January 20, 2024 • 54 mins
In this classic series from Stuff to Blow Your Mind, Robert and Joe discuss the history, mythology, culture and nature of tea. So start a kettle and prepare to listen with your favorite cup… (originally published 02/02/2023)
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Speaker 1 (00:06):
Hey you, Welcome to Stuff to Blow Your Mind.
Speaker 2 (00:07):
My name is Robert Lamb and I am Joe McCormick,
and it's Saturday. We're heading into the vault for a
classic episode of the show. This one originally aired on
February second, twenty twenty three. This is part one of
our series on Tea Hope you enjoy.
Speaker 1 (00:27):
The first cup caresses my dry lips and throat. The
second shatters the walls of my lonely sadness. The third
searches the dry rivulets of my soul to find the
stories of five thousand scrolls. With the fourth, the pain
of life's grievances evaporates through my pores. The fifth relaxes
my muscles and bones become light. With the sixth, I
(00:49):
find the path that leads to the immortal ancestors. Oh,
the seventh cup, better not take it. If I had it,
the only feeling is the fresh en blowing through my
wings as I make my way to Pung Lai.
Speaker 3 (01:08):
Welcome to Stuff to Blow Your Mind production of iHeartRadio.
Speaker 1 (01:18):
Hey, welcome to Stuff to Blow Your Mind. My name
is Robert Lamb.
Speaker 2 (01:22):
And I'm Joe McCormack, and today we're going to begin
a series on tea. Yes, t the beverage and the
plant that it comes from. Now, Rob, you began today's
episode by reading a Is this a poem or a song?
Speaker 1 (01:37):
This is a poem by Lu Toong from the Tang
dynasty titled Seven Bowls of Tea, and it's it's pretty
widely cited. I ran across various like tea blogs talking
about it and sometimes saying that this is overly sited
in the literature of tea, especially in the West, and
(01:58):
I think with good reason, because it's it's amazing. It
captures this just intense enthusiasm for tea. And also it's
essentially about a man drinking way too much tea during
the course of the day that brings him to the
to the very brink of like blinking out of physical
reality and going to toping lie the mystical mountain where
(02:20):
you have fantastic creatures and immortal beings.
Speaker 2 (02:23):
So you don't want to do the seventh cup because
that will just essentially you will leave your body in
the place where you currently reside.
Speaker 1 (02:31):
Right, But it's not it doesn't seem to be a
case where you have to worry about like crashing with
that seventh cup. It's just the seventh cup is one
pleasure beyond that which you should grant yourself. You should.
You have to show restraint because you still have stuff
to do here in the mortal realm.
Speaker 2 (02:48):
Well, I like the way that the poem escalates because
at the beginning it's more just about the like the
first line is about the sensory experience, caresses, dry lips
and throat. It's it's happening in the mouth. And then
after that it's like mood, you know, shatters the walls
of my lonely sadness. That's mood stuff. That's level two.
But beyond that, you're like talking about communing with other beings,
(03:10):
the path that leads to the immortal ancestors.
Speaker 1 (03:13):
Yeah, it gets very spiritual towards the end, transformative.
Speaker 2 (03:16):
Even I've never gone six cups in on caffeinated tea,
but I don't doubt it.
Speaker 1 (03:23):
Yeah, I my wife and I probably have, but only
through re steeps. We're big into picking out a good
tea that you can resteep several times. So I could
probably write a similar poem about, like, you know, steeps
one through four or five on a particular tea that
(03:44):
I like, because sometimes you get get the you get
an interesting tea, and it changes like cup. Cup one
might actually not be the best cup, and it's your
second or third steep where things maybe become a little
more nuanced, a little less sharp. I found that to
be the case with some of the poorer teas that
(04:04):
I really like.
Speaker 2 (04:05):
I assume does the caffeine content become less powerful as
you go through multiple steeps.
Speaker 1 (04:11):
That is my understanding, and I believe that is my experience,
and that's one of the reasons I tell myself that
it's okay to have so many cups of tea during
the course of an afternoon because I'm getting decreased returns
on the cup from a caffeine standpoint. But yeah, we've
touched on tea in the past, but I don't think
we've ever done a proper deep dive on this most
(04:34):
splendid beverage, not just splendid, but really one of the
most popular beverages in the world. You could probably make
a case for it being the most popular. There's a
great deal of variety to how it's cultivated, prepared, brewed,
and consumed, and yeah, there's no denying its appeal. And
it's importance weaves in and out of global history, various cultures.
(04:57):
It factors into mythology, literature, politics, and much much more.
Speaker 2 (05:02):
Yes, And to clarify something here, I guess we should
do this at the beginning. There's a little bit of
confusion in English. I don't know if it's like this
in other languages, but at least in English. There are
a lot of things that we call tea that are
not made with the tea plant. So we use the
word tea as like a generic synonym basically for an infusion.
(05:22):
Anytime you take a substance, herbal or otherwise, and you
expose it to hot water in order to extract some
kind of flavor or chemical compounds into the water, and
then you drink the water, people will call this a
tea no matter what it is. So you've got herbal
teas made from everything from like camomal to turmeric to mint,
or even cases where people will refer to meat based
(05:45):
broths as like beef tea, but there is no really.
But there is also the specific tea plant, the leaves
of which are used to make tea proper. And it
is this plant and its eponymous infusion that we're going
to be most focusing on in these episodes.
Speaker 1 (06:02):
And obviously there are various blends that have taken place.
There's so many teas available now, especially loose leaf teas
where you'll have like little bits of dried flavor bits
that are not tea, but still the primary ingredient is
the dried tea. Now, I think one of the other
exciting things about this is and this is going to
(06:22):
be a fun one to hear from listeners because I
know everyone out there you have your own individual story
with tea. You probably have your own cultural story with tea.
For my own part, I've come to like a number
of different teas. I want to also throw out an
important caveat that I would not say that I am
like a tea super nerd, you know, like I'm not
(06:43):
a connoisseur of teas, So I'm not going to be
speaking from that vantage point in these episodes. But I've
grown particularly fond of these pooh Air teas, which we'll
discuss in due course. I like several things about them. Obviously,
I like the various tastes. They often have this kind
of dark, earthy or sometimes there's lighter, but there's often
(07:04):
an earthy tone to them sometimes compared to hay, and
that is a flavor profile that I find it works.
You get interesting results when you do re steeps on it,
because the hay taste might be a bit strong in
that first cup, but then cup two or three is
generally the comfort zone for me personally. I also really
(07:26):
love how so many of these particular teas are preserved
in bricks or pucks. Sometimes you have to break up
the brick with a little specialized knife, and I like
the ritual of that. I also like it when it's
a little puck that's already been prepared, often circular, sometimes
heart shaped today and that can be a lot of
(07:48):
fun as well, and also makes it a little handy
easy to get into the tea bag.
Speaker 2 (07:52):
Rob, I seem to recall you getting very into the
idea of some kind of disgusting nineteenth century way of
preparing coffee that involved like brick or puck based concentrate.
Am I remembering that right now?
Speaker 1 (08:04):
Oh? No, no, no. I think I was interested in
the study of like Civil War era instant coffee, but
none of it sounded like anything I wanted to even
experiment with.
Speaker 2 (08:15):
Okay, no, no, no, I just meant that you were
interested in the idea and not that like you, oh yeah,
hawking it's virtues as great coffee.
Speaker 1 (08:22):
No, No, it's just it's interesting history like the and
it kind of speaks to the importance of caffeinated beverages
to the people who consume them. You'll have situa like
war situations where people realize, hey, these soldiers need coffee,
these soldiers need tea. How do we get that to them?
What is the most cost effective means of doing so?
What happens when the product is bad? How do the
(08:46):
soldiers in the field relate to this additional indignity. I
also love how tea is like anything else. There's nothing
like great branding. I love some of the names of
the teas that I have enjoyed, Like there's one called
the Bewitched Emperor, there's one called Evil Snake King, and
so yeah, I'm obviously these are just the labels given
(09:07):
to these and these are the English I think that
these are translations though, of what they're actually called in
the case of these two in China as well. But
I just love the idea that is wrapped up in
the branding for these as well. It makes me feel
like I'm not only enjoying an afternoon cup of tea,
but I'm engaging in something possibly supernatural.
Speaker 2 (09:29):
Well, I would say that I sense no other beverage
to have as rich an array of supernatural associations as tea.
Speaker 1 (09:38):
Yeah, I think so. Like there's just there's so and
it's one of the things that's interesting but also could
probably be intimidating at times. Is you get into not
just tea culture, but various tea cultures that all have
various practices of how you're supposed to prepare it, how
you're supposed to consume it, and so forth. I mean
(09:59):
Macha from Japan is of course a great example of this,
and just on its own can be a wonderful tea. Yeah,
there are just so many, so many fascinating teas out there.
We're going to touch on some of the tea cultures
as we proceed through these episodes. But how about you, Joe,
what's your personal story with tea?
Speaker 2 (10:19):
Well, I am not really a tea drinker, not because
I dislike tea. I mean, when I have it, I
enjoy it, But I think it's because for me personally,
there is simply not room for additional caffeine in my life.
I have my morning coffee routine, and I have to
be very careful even with that, because if I have
too much coffee, I will spend the rest of the
(10:40):
day and night having visions of the doom of all
and just hear the screams of a dying planet like
I get the fear bad. And it's strange. I wasn't
always like that. I can think years back, I used
to hang out with my friends and drink cup after
cup of coffee and I was fine. Something happened to me,
and now I cannot handle that much caffeine. It just
(11:01):
wrecks me. So after I've had my daily coffee, I
do not have tolerance for anything else, no tea proper,
no second or third cup whatever. So in order to
do caffeinated tea, I think I would have to do
a full switch out and have it instead of coffee,
which I've never tried to do. But occasionally I do
enjoy non tea teas. I like some herbal teas, lemon
(11:23):
ginger infusions and stuff, and I guess they do make
decaffeinated tea, but I've just never gone down that path.
Speaker 1 (11:30):
M Yeah, yeah, I'm like you, and that I can't
quite put aside the morning coffee. I've gotten it down
to just two cups of coffee, my initial wake up
cup and then the second cup of coffee, and then
everything after that for me is tea. Generally it's one
tea bag, multiple steeps of set tea bag. And it's
(11:50):
worth keeping in mind when thinking about the caffeine. Now,
this is just general, and this maybe can't be applied
completely across the board, but generally speaking, a cup of coffee,
a standard cup of coffee is gonna have somewhere between
one hundred, one hundred and twenty milligrams of caffeine. Meanwhile,
a cup of black tea is gonna have forty milligrams
of caffeine. Green tea's gonna have thirty. Green and white
(12:12):
tend to have the least amount of caffeine, followed by oolong.
These numbers are pointed out by Laura C. Martin, who's
excellent book A History of Tea is one of the
sources that I'm going to keep coming back to in
these episodes.
Speaker 2 (12:24):
Okay, so even if I did try to incorporate some
tea into my daily routine, it would not be equivalent
to drinking the same volume of coffee.
Speaker 1 (12:36):
Yes, that seems to be the case. Now that being said,
there are so many ways to prepare tea, and certainly
you could drink enough tea, you could drink those six
fresh steeps of tea and risk of transporting yourself to
the mystic mountain. So it's always always a possibility. And
everybody's different, you know, And I think our relationship with
caffeine does change as we age, so naturally, yeah, you
(12:57):
don't have to be a total tea nerd or immerged
to any degree within an Eastern culture of tea to
be into TV, because tea has spread around the globe
by this point. Tea culture now encompasses everything from British
high tea to Southern sweet iced tea, Taiwanese bubble tea,
to things like Senegaluese tea and their Tibetan tea preparation
(13:22):
methods that are also rather distinct. And again we'll come
back to some examples of these later on. But I
thought an interesting place to start might be too. Instead
of starting with the familiar or even anything in the
actual real world, we might start off by getting into
the mythological origins of tea. Even before we get into
(13:43):
the botanical realities of tea, we might start in just
purely mythic and I think mostly Chinese mythological origins for
this splendid beverage.
Speaker 2 (13:53):
Oh wait a minute, Wait a minute. If we're getting
into a myth about a psychoactive substance and its ancient
Chinese myth, are we going to meet the divine farmer
once again?
Speaker 1 (14:04):
Yes, yes we will, because of course, if it involves
something that you should eat or shouldn't eat, and is
a plan of some sort, then yeah, the divine farmer
Shinong has to show.
Speaker 2 (14:16):
Up Shinong putting things in his mouth for everybody's benefit.
Speaker 1 (14:20):
That's right. Yes, we've talked about Shinong before on the show.
He's a pretty important figure in Chinese mythology and he's
tied to myths concerning various botanical substances. His name literally
means divine farmer. He's a culture bearer, a god. He's
attributed with the invention of agriculture and the introduction of
(14:41):
agriculture to human beings. He's an important name in Chinese medicine.
He's said to have invented various farm tools and musical instruments,
So there's a lot that this mythological figure is attributed with.
And you know, obviously as a mythological figure, he is
sort of summing up and condensing a lot of the
things that actual human beings did over the course of generations.
(15:05):
Figuring out which plant has a medicinal property or seems
to which plant is good to eat, which plant will
kill you, that sort of thing. You should definitely look
up some images of him, because he's He's often depicted
as this kind of squat older man with bovine or
ox like characteristics, often kind of wide set eyes, and
(15:27):
even one of my favorite things about him is he
often has these kind of nub like horns. Now I
have seen depictions I think these are more modern, but
it could be wrong where he has like full blown
horns like a hornet deity. But generally it's these kind
of nubs where he looks just again, very very bovine.
Speaker 2 (15:44):
Would you call them buds? Are those called buds?
Speaker 1 (15:47):
Yeah? They kind of look like like buds. Yeah, Like,
if you don't know what you're looking at, you might say, well,
why does that man have two bumps on his head?
And it's because it's invoking this kind of ox like characteristics,
a character stick of the character. And in some tales
he was said to have had the head of a dragon,
others the head of an ox. And so we do
(16:08):
have to remember that he is a god, of course,
so it's natural that he might have some qualities like this.
There are various tales about his birth, including some traditions
that relate his incredible rate of maturity. One version said
that he could talk at three days old, he had
all of his teeth, etc. And in some accounts his
(16:29):
father was an actual dragon.
Speaker 2 (16:31):
Wait when you said had all of his teeth, you
meant he was like born with all of his teeth,
or he had all of his teeth when he was
three days old.
Speaker 1 (16:37):
His memory serves, and I believe this is related in
the book Chinese Mythology by yang An and Turner, there's
tales that's like, all right, at three days he had this,
At four days he had this. So he's just maturing
at a rapid rate, where at like three months old
he knows everything about agriculture and he's able to teach
it to humanity. Okay, but the basic story with Shin
(17:00):
own concerning plants is that he not only gave humans
the knowledge of agriculture, he also sussed out which plants
were useful in medicine and which ones were food, and
also which ones were poison And he did this, of course,
by testing them all himself. In some tellings, he's not
actually eating them. He's thrashing them with a reddish brown whip,
(17:22):
like a whip that is. And there's a lot you
can get into with the symbolism of it. I've seen
that it's there's something to it that this is kind
of the color of dried blood. Other times he has
a cauldron. So yeah. In some cases he says to
have some tools that he's using. But in many tellings
and certainly many artistic interpretations, he's testing all these various
(17:43):
botanicals out by eating them, and then afterwards he passes judgment.
He's okay, this this is a plant that would be
good for medicine, so I'm going to put it into
my right hand bag. This one is good for food,
so it's going into my left hand bag, and he
sorts it generally like that.
Speaker 2 (17:59):
What about the one that are poisonous.
Speaker 1 (18:03):
There's one tale where if something's poisonous, he just wants
to stop it, Like, I think there's a story that's
related about Ginger, where originally Ginger was said to be
poisonous and Shinong took a look at each he like
he checked it out and he's like, yeah, this is horrible.
I want to stomp on it as well. And then
Ginger had to change in order to be accepted, and
(18:24):
that's when Ginger went underground. Oh beautiful. Yeah, so yeah,
I want to explore that one more at some point
because I don't really understand all the meaning going on there,
but it's it's it's interesting now. I don't know if
we've talked about this version of the story with Shinong before,
but as Yang'an and Turner point out, in Chinese mythology,
some versions also state that Shinnong is particularly good at
(18:48):
figuring all of this out because he has a crystal
stomach and he can see everything that's going on inside
of his own internal organs as he's digesting things.
Speaker 2 (19:00):
It's like top ar. They open up his stomach and
they can look inside and see it see all the
parts working.
Speaker 1 (19:06):
Yeah, yeah, I just I love it. I definitely picture
this as kind of like almost some sort of an
android body that he has going on underneath his robes
here that he can pull it up, and yeah, it's
just crystal organs under crystal skin, and he can observe
every little detail going on in digestion. So in some
versions of the story, the first plant he was said
(19:28):
to taste was a green leaf, which once he put
it in his mouth and swallowed it, it went on
a grand tour of his insides, cleaning up everything along
the way, and again crystal stomach, so he gets to
watch it go.
Speaker 2 (19:41):
Okay, So it's kind of like a dryer sheet or something.
Speaker 1 (19:44):
Yeah, yeah, I guess. This particular plant was referred to
as cha, which means to inspect, which eventually got confused
in later tellings with cha, which is the exact same
phonetic sound but a different Chinese character. So the story
becomes later on that Shinong was poisoning himself upwards of
(20:08):
seventy times a day, testing out the world's plants to
determine which ones we could use for various purposes, and
if something got on top of him he got some
poison going around in his system, he would turn to
the cleansing power of tea to detoxify himself.
Speaker 2 (20:23):
Oh so, by the way, you should not derive actual
use value from that. But yeah, so in this version
of the story, T is like a universal antidote, right.
Speaker 1 (20:34):
And my understanding too is that older versions of the
story are not referring to T, but it becomes Tea
and later tellings of the story though this eventually catches
up with him. I was reading in that book that
one day he is said to have tried a yellow flower,
(20:54):
and upon trying the yellow flower, it broke his intestines
into pieces. He sees this through his stomach, his crystal stomach.
This occurs just the moment he swallows it, and he's
quickly trying to, you know, get himself some tea so
he can cleanse everything up, but it is too late.
He dies, and the plant that does this to him
(21:16):
becomes known as the intestine breaking weed.
Speaker 2 (21:20):
That is brutal in so many ways, especially because it
imagines the intestines as brittle rather than elastic. I mean,
I guess you could think of them that way.
Speaker 1 (21:33):
Well again, it makes me personally think of Shinong's crystal
organs as being like glass. And then the shattering is
kind of like when a cartoon character bites on something
that's too hard, and their teeth do that cartoon shattering thing.
That's what I picture in my mind happening to Shinong
here portion on. Yeah. Now there's a book, Shinong's Herbal Classic,
(22:05):
a later Han dynasty book that includes a great deal
of knowledge related to various botanical substances, and this book
is attributed to Shinong, likely based on oral traditions. It
includes a passage on tea, telling us that it's bitter
and share some details about when, how and where it
grows best. But as Laura C. Martin points out in
(22:26):
a History of Ta, references to T in this book
were probably not original to it, as the character for
Ta itself didn't come into usage until seventh century. But
more on the timeline of tea in a bit, because
we're still for now in the mythic.
Speaker 2 (22:41):
Timeline, okay, But talking about this book attributed to Shinong,
the idea is that probably there were earlier versions of
the book that did not have the tea passages, and
in recopying through the year's tea passages were inserted by
some editor or copyist exactly.
Speaker 1 (22:57):
Yes, Now, there are a couple of other tea related
myths here. This is one that Young Haan Turner point out.
It's a creation myth of the Dang ethnic people known
outside of China as the Palolang people in Unan Province.
And it's said that in this creation myth, one hundred
and two tea leaves went around and around in the
(23:19):
air for thirty thousand years and then transformed into fifty
one young men and fifty one young women. That's the
beginning of humanity. Now there's another one. This is a
This is a tea myth that largely emerges from India
rather than China. As Martin points out, the early history
of tea centers around China. But the plant is indigenous
(23:40):
to the Assam region of India in addition to southwestern China.
Yet it seems that it was a little known or
used in India prior to the sixth century.
Speaker 2 (23:48):
Seat and if you don't know where it is, Assam
is located in northeastern India. So the area of origin
for the tea plant, we think is basically southwestern China
northeastern India.
Speaker 1 (24:01):
Yeah. Yeah, though it does seem like it was better
known in China as opposed to India. But of course
we see a fair amount of cultural exchange between India
and China, and of course the most famous example of
this is of course Buddhism, and this particular story does
(24:22):
involve Buddhism as well. It's the story of Bodhidharma, who
was a fifth century semi legendary Indian prince who, much
like the Buddha himself a thousand years earlier, came to
see the emptiness of wealth and abandoned all of it
in the quest for enlightenment. He became a Buddhist monk,
and after many years of study, he travels to China
(24:43):
to reintroduce Buddhism and found Buddhism had been introduced into
China previously, but this most period where maybe it was
waning a bit, and he said to end up becoming
the founder of Chan Buddhism in the process. But while
he's in China, after visiting the emperor on this trip,
he retreated. He eats to a shovelin temple and here
he begins a long period of devoted meditation and asceticism.
(25:08):
So depending on the tail, and again there are different
versions with this. With most of these stories, he either
stares at a wall for nine years in meditation, or
he gives up sleep for nine years so that he
can really double down on his meditation. In one version
of this story, he grows so sleepy that he reaches
out and he grabs a leaf, like a random leaf,
(25:29):
and he just shoves it in his mouth to chew
it as a way to perk himself up. And his
luck would have it, this plant is tee and it
really does perk him up because it we'll discuss it
a bit, it contains a stimulant. There's another version of
this tale, and this one I got in trouble for
sharing at the Venner table in my post research excitement.
But in this other version, he's getting sleepy and he
(25:53):
pulls off his own eyelids because it's like, oh, heavy eyelids,
they keep shutting. I'm trying to meditate, but I keep
falling asleep. So he just pulls the eyelids off, throws
them on the ground, and then a tea plant grows
from where the eyelids fall. So, in either case, according
to this legendary account, he discovers tea and passes it
(26:16):
on to the other monks to assist them in their meditation.
All right, So there's just a taste of some of
the mythological stories involving the origin of ta, this spectacular
plant that is either discovered or perhaps even created out
of some sort of inspired inside by a legendary or
semi legendary individual.
Speaker 2 (26:37):
Now, when it comes to the T plant itself, there
were a few things that I actually did not know
until recently. I don't know if I should be embarrassed
about not knowing these, but I was just pretty much
in the dark about tea. But one thing I discovered
was that, apart from the issue of things being called
tea just actually being an infusion of anything, even when
you're talking about the T plant itself. Previously thought that
(27:01):
the main varieties of tea you hear about, like green
tea and black tea or maybe oolong tea, were from
different plants. But actually these are all from the same
plant as far as I can tell. They're just different
preparation and curing methods. Correct.
Speaker 1 (27:18):
Yeah, yeah, they're essentially we're talking about one single species
of plant. Camellia senensuss Camellia sinensus is an evergreen shrub
or tree, and you know Asterix there, we'll get to
that that produces small white petaled flowers. In the wild,
it will eventually reach tree size, but in situations where
(27:41):
it's been cultivated, generally they're kept at a shrub size
via pruning. They're typically kept at like a meter or
three feet in height, as that's an ideal height for picking.
Speaker 2 (27:53):
Yeah, and so you have these top layers of leaves
that come out, and I think they refer to those
as flushes, like the leaves keep protruding and then the
top young leaves are harvested.
Speaker 1 (28:04):
Yeah, and while we're essentially talking about one species, there
are two varieties. There's Camillias Andensus. This is the one
that's indigenous to western Yunnan in China. And then there's
a variety of that Camillia Senensus issamica. This is indigenous
to the Assam region of India as well as parts
of Myanmar, Thailand, Laos, Cambodia, Vietnam, and southern China. Now,
(28:28):
these two varieties they cross pollinate easily, so they are
also blends of the two. But Martin stresses that they're
actually not that different in taste either. So the varying
tastes and colors of different teas they stem from the
way we process them, whether you're talking about black or
green oolong, et cetera. And so either variety of tea
(28:49):
leaf processed the same way will basically be similar. But
at the same time, we don't want to discount traditions
surrounding particular teas. It's one of those things. It's kind
of like, you know, wine tastes or any kind of
like cultural food tradition. There's a lot tied up in
knowing where something comes from as well, and some of
(29:10):
that translates into the taste for the average consumer. Sometimes
it's something that translates into the connoisseur's taste experience, and
sometimes you're getting into an area where yes, you're being
primed that this particular I don't know, you know, this
wine stems from this vintage versus this vintage, this winery
(29:32):
versus this winery, etc. Yeah.
Speaker 2 (29:34):
Yeah, I mean, I think there are a lot of
different foods that maybe you actually couldn't tell the difference
in a blind taste test. But then again, it might
be cool to enjoy an authentic version of something knowing
the history behind it, like knowing where it comes from
and being able to think about that and so forth.
Speaker 1 (29:52):
Exactly so in the wild, tea plants are generally going
to thrive in an open woodland area or on the
edge of the woodlands where they can benefit from the
shade of larger trees. As such, when cultivating tea plants,
they're generally grown alongside shade trees. These, as Martin points out,
(30:12):
not only provide shade, but also it keeps weeds away
and enriches the soil and generally the leaves and the
buds or what are harvested fresh leaves generally contain about
four percent caffeine.
Speaker 2 (30:25):
I'm reading, and I was wondering about this because I
had read that it is maybe we can get more
into this when we do some of the cultural history.
But I have read that tea leaves were traditionally treated
as a food plant in China, more so than a
beverage plant, and the beverage stage came later. And so
(30:46):
apparently you can eat tea leaves. You can just prepare
them like a green and chew them up and eat them.
People do this sometimes and it's fine, though you need
to be careful about how much you eat, obviously, because
you don't want to overdose yourself.
Speaker 1 (30:59):
On caffeine right right, because most of us don't have
crystal clear guts that we can look at and to
determine what's happening, you know, by the moment. But yeah,
that'll be fun to get into in a subsequent episode.
The history of tea as a beverage is also the
history of a food, so yeah, I'm looking forward to that.
(31:29):
But coming back to the caffeine, this is a question
that applies of course to tea, but also to other
caffeinated beverages, or at least ones that have a natural origin,
Like why is there caffeine in the leaf? Like what
is there? Well, why is that substance that, for us
humans is a stimulant that kind of manipulates us as
(31:51):
a consumer of the plant, Like why is it even there?
Speaker 2 (31:54):
To begin with great question, So as a jumping off
point to answer this, I want to refer to an
article I was reading on the subject by previous show
guest Carl Zimmer, who is one of our favorite science writers.
He's been a guest on the podcast before. Maybe we'll
get him back again someday, but he came on to
talk about his book on genes and heredity called She
(32:15):
Has Her Mother's Laugh, which is a fantastic book. And
so Carl Zimmer had an article in twenty fourteen in
The New York Times called how Caffeine Evolved to help
plants survive and help people wake up? And he begins
by pointing out some rough stats about the popularity and
power of coffee and caffeine, saying the world consumes roughly
twenty six thousand cups of coffee per second. That's a lot.
(32:37):
That caffeine is probably the most widely used psychoactive substance
in the world. But there's an interesting thing about caffeine,
which is that it has a number of different associated
plants that it comes from. So, for example, there are
coffee beans. Coffee Beans are the seeds of a genus
of flowering plant called Caffea or Coffea in the family rubiaishi.
(33:03):
These plants are native to tropical Africa and tropical Asia.
There is of course tea. Tea again is made from
the leaves of the evergreen shrub Camillias and ensus, which
is native to East Asia. There's mate made from the
urbamate plant, which is a holly shrub native to South
America scientific name Ilex paraguariensis. And then you've even got chocolate.
(33:25):
Chocolate also contains caffeine. Chocolate's made from the seeds of
the cacao tree or theobroma cacao. Theobroma, by the way,
means food of the gods. Theo roma and historically was
not always used as an ingredient in sweets and desserts.
The main way we in the United States consume it today.
It was often consumed as a bitter, hot, or cold beverage,
(33:48):
kind of similar to how we consume coffee, which of
course would have carried a punch of caffeine, and chocolate
does have caffeine.
Speaker 1 (33:55):
I think our Invention episode where we talk to Jeff
Beach Bomberry, we talked a little bit about ancient recipes
for hot chocolate.
Speaker 2 (34:05):
Essentially, But it's kind of interesting to look at this
geographic distribution and say, how do all of these different
plants that are not closely related to one another independently
make this same compound. We know why humans like caffeine,
but what does caffeine do for the plants, and how
(34:27):
did all these diverse different species evolve to make it?
Speaker 1 (34:30):
Well.
Speaker 2 (34:30):
This article looks at a study published in the journal
Science in twenty fourteen, where researchers detailed an effort to
sequence the genome of a species of coffee plant responsible
for many of the world's coffee beans. This remember, coffee
comes from the genus Coffea or coffea, and this is
Coffea canaphora. The study is by France. Oh, I do
(34:53):
not know how to pronounce this last name, Deneud is
how the name is spelled at all, and the title
is the coffee genome provides insight into the convergent evolution
of caffeine biosynthesis. Again, that's in the journal Science twenty fourteen.
So one thing this study looked at is how caffeine
is actually synthesized in coffee plants. And it turns out
(35:16):
it is a multi stage transformation of molecule that it
begins with a compound called xanthozine, and the coffee plant
manufactures several enzymes that act on this compound. So one
enzyme removes an arm of the molecule, another enzyme adds
a new arm, Two more enzymes come in and add
two more clusters of atoms, and after all these transformations,
(35:39):
you finally have transformed xanthezine into caffeine, and the enzymes
involved in this multi step transformation are called in methyl transferases.
They are found in all plants, and they do generally
this sort of work, building specific compounds, many of which
plants use to defend themselves against predator or parasites. And
(36:02):
one example of a compound manufactured with the help of
in methyl transferases that zimbercites in the article is salicylic acid,
which is a compound produced by willow trees, which actually
turns out to be a potent pain reliever in animals
like us. Salicilic acid is the chemical basis for aspirin.
But what about the enzymes that manufacture caffeine specifically in coffee. Well,
(36:27):
the authors determine that some time ago, in the evolution
of the coffee plant, a gene for creating one type
of in methyl transfer enzyme underwent a series of mutations
to produce a variety of enzymes which would eventually create caffeine.
And so one of the co authors is quoted in
Carl Zimber's articles. This is by Victor A. Albert saying
(36:50):
they're all descendants of a common ancestor enzyme that started
screwing around with xanthezene compounds, So the plants are just
kind of like doing all these little variations on this
originator molecule and producing these derivative molecules that in many
cases are physiologically active or psychoactive on animals. And it
turns out scientists had already discovered that caffeine was created
(37:13):
by the action of in methyl transferrass in cocaw trees
and in the tea plant, so similar molecular frameworks are
going on within coffee plants, within the tree that makes
chocolate or cocow, and within tea plants. However, the researchers
also found that the enzymes for making caffeine in these
(37:35):
different plants did not all evolve from the same ancestors.
So this would be a case of convergent evolution, different
branches on the tree of life evolving the same solution,
the same phenotype independently. So you can think of a
million different examples of this. One is wings. Birds and
bees both evolved flapping wings independently for flight. They didn't
(37:58):
get them from a common ancestor that had wings. They
know their last common ancestor did not have wings, and
they independently, separately came up with the same solution. Now,
when you see convergent evolution, you see different streams of
evolution converging on the same trait or the same solution
to an environmental problem. It's usually a sign that that
(38:19):
trait or solution is pretty good. It's a powerful adaptation,
and there's a big survival and reproduction payoff. So it
would seem, based on the evidence of convergent evolution, that
producing caffeine is definitely good for something for the plants.
So what is it really good for. Well, there are
a few things we can talk about. One is activity
in poisoning or deterring predation by insects. So, like so
(38:43):
many of the plant based compounds that humans ingest on
purpose for their psychoactive properties, caffeine seems to be at
least in part useful for deterring predation by insects. Insects
would of course naturally like to eat the leaves and
the seeds of the cope plant, but high levels of
caffeine are toxic to them, and this relationship can be
(39:05):
seen further in the fact that the fruit fly Drosophila
drosophala has the ability to taste the presence of certain compounds.
I was reading about how they have an array of
at least sixty eight known These are called seven transmembrane
goostatory receptors or goustatory receptors are grs and goustatory meaning taste.
(39:27):
So these goustatory receptors allow the fly to sense the
presence of compounds that could kill it or harm it
and avoid eating them. Caffeine is one of those compounds.
Fruit Flies appear to have a suite of receptors, including
one called g R sixty six A, that work together
to sense the presence of caffeine in whatever they're eating
(39:49):
and allow an avoidance response to take over. Now, I
think it's interesting to put that together with the fact
that in the human experience, most alkaloids taste. Bitter. Alkaloids
are a broad class of nitrogen bearing organic compounds that
plants make, many of which have physiological effects on humans
(40:11):
and other animals, effects ranging from you know, all your
standard types of poisoning and death to psychoactive effects such
as the stimulant effect of caffeine. So bitter taste often
causes animals to reject a food source. So I think
it's kind of reasonable to put all this together in
wonder if the sensation of bitterness when ingesting plants rich
(40:32):
in alkaloids is perhaps a protective response that tells us
to stop consuming these plants and reject them, similar in
effect to the way that a fruitfly has the ability
to taste and reject caffeine, though with a different evolutionary backstory.
Speaker 1 (40:47):
Yeah, that's a good point. I mean, it makes me
think of, you know, the obvious of example of say
a child being introduced to coffee and finding it disgusting
because it is bitter. And also we have to think
about the fact that that the chocolate unsweeten has a
very bitter taste to it as well, though of course
in both cases coffee and chocolate, there is of course
(41:09):
a process involved here we're not going to really get
into with coffee and chocolate between plant and even the
unsweetened food product, but that's something we can come back
to in the future. I love to do something on chocolate,
say in the future.
Speaker 2 (41:25):
Absolutely, And yeah, it's interesting to think about the complex
human reaction or response to bitterness that it seems bitterness
is probably primarily biologically relevant in getting us to reject foods.
You know, it's like this has something in it that
I don't want to get too much of, So I
probably don't want to eat too much of this.
Speaker 1 (41:42):
Yeah. So many of the naturally occurring pesticides that we consume, Yeah,
they have some sort of a strong flavor that would
tend to convince most humans to avoid them, certainly, and
in many of the cases where there are various spices,
avoid them in larger quantities than we traditionally use them.
Speaker 2 (42:00):
And yet we can really get a taste for them.
I mean, I like the bitter taste of coffee and
of chocolate and of tea and so forth. It might
have to do with like it's a level of bitterness
that doesn't reach kind of a threshold which you would
find it disgusting, like it's like below the bar for rejection.
Or it could be a totally it could be a
(42:21):
learned response. I mean maybe naturally people don't like bitter
stuff in any quantity, but if culturally they learn to
appreciate it, I don't know, maybe maybe that's what's making
the difference there.
Speaker 1 (42:32):
Oh well, I mean in cocktail culture, for example, you
have a you know, a whole spectrum of bitter drinks.
You know, sometimes you're just adding a little bitter taste
via bitters in many cases, to to offset sweetness and
give you a certain flavor profile. But some people go
especially hard for those those bitter drinks. They're like, I've
(42:54):
never tried one of these, but you have these recipes
floating around for mixed drinks that contain like multiple bitter
components to try and create like some sort of uber
bitter concoction, which is not for me, but I assume
it's for some people who have developed a taste for
all of those bitter components.
Speaker 2 (43:14):
Well, I mean, I do think about how many of
the bitter food almost all of the really enjoyable bitter
foods and beverages I can think of or psychoactive in
one way or another. I mean, I guess not like
you know, bitter greens or something. You know, I like
greens that can be bitter, but I think of coffee,
which has caffeine. I think of chocolate, which has caffeine.
I think of tea, which has caffeine. Or I think
(43:36):
of alcoholic beverages that are bitter, like you know, like
hoppy beers and so forth.
Speaker 1 (43:41):
Yeah, so it's almost like on some level, our bodies
saying this tastes bad, but something good is happening.
Speaker 4 (43:47):
Yeah, but okay, So caffeine, one of it rolls within
a plant might be to deter insects or other animals,
maybe from eating the leaves of the plant.
Speaker 2 (44:06):
They got enough caffeine in there. One way or another,
the toxicity of the caffeine will drive the animal away.
Another interesting idea that Zimmer raises in this article is
that caffeine in coffee plants is suspected to work also
by inhibiting the growth and germination of other plants. He
writes that when coffee leaves die and fall off of
(44:29):
a coffee plant, they fall down to the soil below.
The caffeine content seeps into the earth and interferes with
the ability of other plant species in the soil nearby
to germinate. So this helps limit competition for soil resources
and sunlight in the area. Now, I didn't find anything
specifically about whether or not that's true with tea plants
(44:49):
as well, but it could also be the case if
it works for the coffee plant. But one thing where
I did find a parallel between how they think caffeine
is working in coffee plants and tea plants is its
role in pollination. I thought this was the most interesting
of all. So, in addition to deterring insect or animal
predation and perhaps limiting competition from nearby plants, the psychoactive
(45:14):
and drug like properties of caffeine on animals might be
not only an unintended byproduct or side effect of their
physiological activity as a deterrent. They might actually be in
part the point of the compound, or at least one
of the points of the compound, and it would work
like this So coffee and flowering plants that produce caffeine
(45:37):
in their leaves also produce lower doses of caffeine in
their nectar. Now, plants make nectar as a food for
insects as an incentive for insects to spread their pollen.
So the insect gets sugar from the plant, it gets
a meal, and the plant gets help with reproduction and
(45:58):
dispersal when returning it's help spreading its genetic material. Now
here's the really interesting thing. Research has shown that when
insects feed on plant nectar containing low doses of caffeine,
they seem to become more disposed to remember the scent
of the flower where they consumed that nectar, and researchers
(46:20):
believe this may cause the insect to return to that
flower more often and thus spread its pollen more effectively.
So maybe out of just one compound, this one molecule
that the plant creates, it can be getting multiple completely
different effects depending on the dosage in the different part
of the plant. So maybe higher levels in the leaves
(46:41):
will deter insects from trying to eat the leaves, but
lower levels in the nectar will be more like a
cup of coffee for the insect, which boosts the insect's
memory and allows it to return to the same plant
more frequently and spread that plant's genetic material. Toxic and
high concentration, but beneficial to some types of brain function
(47:04):
at lower doses. And it's funny that caffeine has the
same dual effect on humans. I mean, if you have
too much of it, it will kill you. But if
you have these low doses of it that people consume
in beverages and stuff, people use it directly as a
stimulant to improve their brain function.
Speaker 1 (47:20):
Yeah, I mean, coming back to Shinong, the mythical story here,
it's basically an individual god figuring out to what degree
one should consume the world of poisons around us, how
much of this poison is appropriate for desired outcome, and
then which poisons should we not mess with at all?
Speaker 2 (47:40):
Exactly? So I found this so interesting. But anyway, this
was all about the coffee plant. I was trying to
find is the same thing true of the T plant,
And I did, in fact find. A study from just
a couple of years ago is from twenty twenty one
published in the Journal of Insect Physiology. It was by
Gwen Gong at All and it was called Laurel T
(48:00):
polyphenols can improve honeybee memory retention and olfactory sensitivity. So
the background on the study is to read from their
abstract quote. Animal pollinated plants face a common problem how
their defensive anti herbivore compounds may impair or alter pollinator behavior.
Evolution has tailored multiple solutions, which largely involve pollinator tolerance
(48:25):
or manipulation to the benefit of the plant, not the
removal of these compounds from pollen or nectar. The T
plant Camilli s. Senensis is famous for the caffeine and
T polyphenols that it produces in its leaves. However, these
compounds are also found in its nectar, which honeybees readily collect.
(48:45):
So to summarize here, the authors tested the effects of
these two different products of the tea plant, of the
caffeine and the T polyphenols, and they tested it on
the forging behavior of honeybees. And what they say they
found is that honeybees preferred simulated nectar from a feeder
when it contained T polyphenols over a control feeder that
(49:07):
did not contain them. And they also found that bees
that were fed on a feeder laced with caffeine showed
small improvements in learning. Both caffeine and T polyphenols increased
memory retention and showed influences on other behaviors as well,
such as response to alarm pheromones. So it seems that
the T plant may well be adapted to give pollinating
(49:29):
insects small doses of caffeine and T polyphenols for a reason.
It could mean, among other things, that the pollinating insects
are more likely to keep returning to the same plant
and spreading its genetic material. And I thought this was
so interesting. So if this is in fact the case,
it's a more complex relationship than I usually imagine between
(49:51):
plants and the alkaloids that they manufacture and the animals
that they target, because I usually think of the relationship
as a pretty simple one way way interaction, like the
plant alkaloid causes some kind of negative physiological response or
reaction in the animal, and then the animal is deterred
from eating the plant again, or the animal is driven
(50:12):
to evolve like gustatory receptors or taste that make the
plant taste nasty from the first spite, because you know,
it's ancestors that didn't have that may have died. But
this is a more complex implied relationship. I don't know
exactly what to compare it to. I mean, it's almost
like the cultivating of an analog of an addiction, but
one with I don't know, survival benefits for the bee
(50:36):
as well, because it allows them to keep returning to
a food source.
Speaker 1 (50:40):
So before we got into all this here, if I
were put to the test, I would have just said, well,
caffeine implants is just about keeping some things from eating them,
and we've managed to manipulate that situation for our own benefit.
But yeah, it sounds like the reality is a lot
more complicated. Of course, you can't really think about purpose
and design and desire in the literal sense when it
(51:02):
comes to the evolution of something like this in various
plant species. But I am kind of reminded of how
some products in the human world will end up with
more than one purpose, Like, for instance, I think of
bag bomb. Have you ever used bag bomb or seen
a container of bag bomb?
Speaker 2 (51:19):
I don't think so. Explain.
Speaker 1 (51:21):
It's like a little greenkin and I believe it dates
back to her about eighteen ninety nine, and it was
it's a salve to put on a cow's udders after milking.
But people started using it because they realized that, hey,
you can put this on dry cracked skin. And so
it's one of these things where it ended up being
there's this whole additional application of the product, an entire
(51:44):
different consumer base that kind of sprang out of it.
It's more complicated, obviously with the case with caffeine and plants,
but it's almost it almost feels like that where there
may be one purpose that's kind of driving the evolution
of this, but then this other use, the other way
that it can enhance the survivability of the plant emerges
(52:06):
as well, and so you have these sort of dual
forces driving it at that point.
Speaker 2 (52:11):
Oh yeah, Evolution loves to repurpose pre existing morphologies, So
like a structure or a chemical capacity, or something that
evolved initially for one reason can always be repurposed when
a new opportunity presents itself. Yeah, and I don't know
specifically what the order would have been in any of
these cases, whether you're talking about coffee plants or tea plants,
(52:33):
but you can imagine a compound. Initially, there is evolutionary
pressure favoring the enzymes to produce that compound because it
I don't know, because it deters predation by animals, or
because it limits competition when the leaves fall into the soil.
And then later something like this relationship with pollinators emerges
using the same compound.
Speaker 1 (52:51):
And then eventually this relationship with human beings who start
cultivating it. So it's fascinating to think about all of
these relationships. All Right, we're gonna go ahead and wrap
up this episode, but we'll be back in the next
episode with more discussion of tea. In the meantime, of course,
we'd love to hear from everyone out there. You might
be thinking to yourself, well, I have some tidbit I
(53:13):
want to share about tea, but surely Robert and Joe
don't want to hear it. No, we want to hear
it right in. We want to know about your individual
or cultural differences and appetite for tea. If there are
other myths or legends or folk tales that you've heard
about about the origins of tea, write in. We would
love to hear from you. In the meantime, will remind
(53:35):
you that Stuff to Blow Your Mind is primarily a
science podcast, with core episodes on Tuesdays and Thursdays. On
Mondays we do listener mail. That's that's when we will
read the messages that come in about these episodes. On
Wednesdays we do a short form artifact or monster fact episode,
and then on Fridays it's Weird House Cinema time. That's
when we set aside most serious concerns and just talk
(53:56):
about a strange film.
Speaker 2 (53:57):
Huge thanks to our audio producer JJ Pauseway. If you
would like to get in touch with us with feedback
on this episode or any other, to suggest a topic
for the future, or just to say hello, you can
email us at contact at stuff to Blow your Mind
dot com.
Speaker 3 (54:19):
Stuff to Blow your Mind is production of iHeartRadio. For
more podcasts from iHeartRadio, visit the iHeartRadio app, Apple podcasts,
or wherever you're listening to your favorite shows.
Hey you, Welcome to Stuff to Blow Your Mind.
Speaker 2 (00:07):
My name is Robert Lamb and I am Joe McCormick,
and it's Saturday. We're heading into the vault for a
classic episode of the show. This one originally aired on
February second, twenty twenty three. This is part one of
our series on Tea Hope you enjoy.
Speaker 1 (00:27):
The first cup caresses my dry lips and throat. The
second shatters the walls of my lonely sadness. The third
searches the dry rivulets of my soul to find the
stories of five thousand scrolls. With the fourth, the pain
of life's grievances evaporates through my pores. The fifth relaxes
my muscles and bones become light. With the sixth, I
(00:49):
find the path that leads to the immortal ancestors. Oh,
the seventh cup, better not take it. If I had it,
the only feeling is the fresh en blowing through my
wings as I make my way to Pung Lai.
Speaker 3 (01:08):
Welcome to Stuff to Blow Your Mind production of iHeartRadio.
Speaker 1 (01:18):
Hey, welcome to Stuff to Blow Your Mind. My name
is Robert Lamb.
Speaker 2 (01:22):
And I'm Joe McCormack, and today we're going to begin
a series on tea. Yes, t the beverage and the
plant that it comes from. Now, Rob, you began today's
episode by reading a Is this a poem or a song?
Speaker 1 (01:37):
This is a poem by Lu Toong from the Tang
dynasty titled Seven Bowls of Tea, and it's it's pretty
widely cited. I ran across various like tea blogs talking
about it and sometimes saying that this is overly sited
in the literature of tea, especially in the West, and
(01:58):
I think with good reason, because it's it's amazing. It
captures this just intense enthusiasm for tea. And also it's
essentially about a man drinking way too much tea during
the course of the day that brings him to the
to the very brink of like blinking out of physical
reality and going to toping lie the mystical mountain where
(02:20):
you have fantastic creatures and immortal beings.
Speaker 2 (02:23):
So you don't want to do the seventh cup because
that will just essentially you will leave your body in
the place where you currently reside.
Speaker 1 (02:31):
Right, But it's not it doesn't seem to be a
case where you have to worry about like crashing with
that seventh cup. It's just the seventh cup is one
pleasure beyond that which you should grant yourself. You should.
You have to show restraint because you still have stuff
to do here in the mortal realm.
Speaker 2 (02:48):
Well, I like the way that the poem escalates because
at the beginning it's more just about the like the
first line is about the sensory experience, caresses, dry lips
and throat. It's it's happening in the mouth. And then
after that it's like mood, you know, shatters the walls
of my lonely sadness. That's mood stuff. That's level two.
But beyond that, you're like talking about communing with other beings,
(03:10):
the path that leads to the immortal ancestors.
Speaker 1 (03:13):
Yeah, it gets very spiritual towards the end, transformative.
Speaker 2 (03:16):
Even I've never gone six cups in on caffeinated tea,
but I don't doubt it.
Speaker 1 (03:23):
Yeah, I my wife and I probably have, but only
through re steeps. We're big into picking out a good
tea that you can resteep several times. So I could
probably write a similar poem about, like, you know, steeps
one through four or five on a particular tea that
(03:44):
I like, because sometimes you get get the you get
an interesting tea, and it changes like cup. Cup one
might actually not be the best cup, and it's your
second or third steep where things maybe become a little
more nuanced, a little less sharp. I found that to
be the case with some of the poorer teas that
(04:04):
I really like.
Speaker 2 (04:05):
I assume does the caffeine content become less powerful as
you go through multiple steeps.
Speaker 1 (04:11):
That is my understanding, and I believe that is my experience,
and that's one of the reasons I tell myself that
it's okay to have so many cups of tea during
the course of an afternoon because I'm getting decreased returns
on the cup from a caffeine standpoint. But yeah, we've
touched on tea in the past, but I don't think
we've ever done a proper deep dive on this most
(04:34):
splendid beverage, not just splendid, but really one of the
most popular beverages in the world. You could probably make
a case for it being the most popular. There's a
great deal of variety to how it's cultivated, prepared, brewed,
and consumed, and yeah, there's no denying its appeal. And
it's importance weaves in and out of global history, various cultures.
(04:57):
It factors into mythology, literature, politics, and much much more.
Speaker 2 (05:02):
Yes, And to clarify something here, I guess we should
do this at the beginning. There's a little bit of
confusion in English. I don't know if it's like this
in other languages, but at least in English. There are
a lot of things that we call tea that are
not made with the tea plant. So we use the
word tea as like a generic synonym basically for an infusion.
(05:22):
Anytime you take a substance, herbal or otherwise, and you
expose it to hot water in order to extract some
kind of flavor or chemical compounds into the water, and
then you drink the water, people will call this a
tea no matter what it is. So you've got herbal
teas made from everything from like camomal to turmeric to mint,
or even cases where people will refer to meat based
(05:45):
broths as like beef tea, but there is no really.
But there is also the specific tea plant, the leaves
of which are used to make tea proper. And it
is this plant and its eponymous infusion that we're going
to be most focusing on in these episodes.
Speaker 1 (06:02):
And obviously there are various blends that have taken place.
There's so many teas available now, especially loose leaf teas
where you'll have like little bits of dried flavor bits
that are not tea, but still the primary ingredient is
the dried tea. Now, I think one of the other
exciting things about this is and this is going to
(06:22):
be a fun one to hear from listeners because I
know everyone out there you have your own individual story
with tea. You probably have your own cultural story with tea.
For my own part, I've come to like a number
of different teas. I want to also throw out an
important caveat that I would not say that I am
like a tea super nerd, you know, like I'm not
(06:43):
a connoisseur of teas, So I'm not going to be
speaking from that vantage point in these episodes. But I've
grown particularly fond of these pooh Air teas, which we'll
discuss in due course. I like several things about them. Obviously,
I like the various tastes. They often have this kind
of dark, earthy or sometimes there's lighter, but there's often
(07:04):
an earthy tone to them sometimes compared to hay, and
that is a flavor profile that I find it works.
You get interesting results when you do re steeps on it,
because the hay taste might be a bit strong in
that first cup, but then cup two or three is
generally the comfort zone for me personally. I also really
(07:26):
love how so many of these particular teas are preserved
in bricks or pucks. Sometimes you have to break up
the brick with a little specialized knife, and I like
the ritual of that. I also like it when it's
a little puck that's already been prepared, often circular, sometimes
heart shaped today and that can be a lot of
(07:48):
fun as well, and also makes it a little handy
easy to get into the tea bag.
Speaker 2 (07:52):
Rob, I seem to recall you getting very into the
idea of some kind of disgusting nineteenth century way of
preparing coffee that involved like brick or puck based concentrate.
Am I remembering that right now?
Speaker 1 (08:04):
Oh? No, no, no. I think I was interested in
the study of like Civil War era instant coffee, but
none of it sounded like anything I wanted to even
experiment with.
Speaker 2 (08:15):
Okay, no, no, no, I just meant that you were
interested in the idea and not that like you, oh yeah,
hawking it's virtues as great coffee.
Speaker 1 (08:22):
No, No, it's just it's interesting history like the and
it kind of speaks to the importance of caffeinated beverages
to the people who consume them. You'll have situa like
war situations where people realize, hey, these soldiers need coffee,
these soldiers need tea. How do we get that to them?
What is the most cost effective means of doing so?
What happens when the product is bad? How do the
(08:46):
soldiers in the field relate to this additional indignity. I
also love how tea is like anything else. There's nothing
like great branding. I love some of the names of
the teas that I have enjoyed, Like there's one called
the Bewitched Emperor, there's one called Evil Snake King, and
so yeah, I'm obviously these are just the labels given
(09:07):
to these and these are the English I think that
these are translations though, of what they're actually called in
the case of these two in China as well. But
I just love the idea that is wrapped up in
the branding for these as well. It makes me feel
like I'm not only enjoying an afternoon cup of tea,
but I'm engaging in something possibly supernatural.
Speaker 2 (09:29):
Well, I would say that I sense no other beverage
to have as rich an array of supernatural associations as tea.
Speaker 1 (09:38):
Yeah, I think so. Like there's just there's so and
it's one of the things that's interesting but also could
probably be intimidating at times. Is you get into not
just tea culture, but various tea cultures that all have
various practices of how you're supposed to prepare it, how
you're supposed to consume it, and so forth. I mean
(09:59):
Macha from Japan is of course a great example of this,
and just on its own can be a wonderful tea. Yeah,
there are just so many, so many fascinating teas out there.
We're going to touch on some of the tea cultures
as we proceed through these episodes. But how about you, Joe,
what's your personal story with tea?
Speaker 2 (10:19):
Well, I am not really a tea drinker, not because
I dislike tea. I mean, when I have it, I
enjoy it, But I think it's because for me personally,
there is simply not room for additional caffeine in my life.
I have my morning coffee routine, and I have to
be very careful even with that, because if I have
too much coffee, I will spend the rest of the
(10:40):
day and night having visions of the doom of all
and just hear the screams of a dying planet like
I get the fear bad. And it's strange. I wasn't
always like that. I can think years back, I used
to hang out with my friends and drink cup after
cup of coffee and I was fine. Something happened to me,
and now I cannot handle that much caffeine. It just
(11:01):
wrecks me. So after I've had my daily coffee, I
do not have tolerance for anything else, no tea proper,
no second or third cup whatever. So in order to
do caffeinated tea, I think I would have to do
a full switch out and have it instead of coffee,
which I've never tried to do. But occasionally I do
enjoy non tea teas. I like some herbal teas, lemon
(11:23):
ginger infusions and stuff, and I guess they do make
decaffeinated tea, but I've just never gone down that path.
Speaker 1 (11:30):
M Yeah, yeah, I'm like you, and that I can't
quite put aside the morning coffee. I've gotten it down
to just two cups of coffee, my initial wake up
cup and then the second cup of coffee, and then
everything after that for me is tea. Generally it's one
tea bag, multiple steeps of set tea bag. And it's
(11:50):
worth keeping in mind when thinking about the caffeine. Now,
this is just general, and this maybe can't be applied
completely across the board, but generally speaking, a cup of coffee,
a standard cup of coffee is gonna have somewhere between
one hundred, one hundred and twenty milligrams of caffeine. Meanwhile,
a cup of black tea is gonna have forty milligrams
of caffeine. Green tea's gonna have thirty. Green and white
(12:12):
tend to have the least amount of caffeine, followed by oolong.
These numbers are pointed out by Laura C. Martin, who's
excellent book A History of Tea is one of the
sources that I'm going to keep coming back to in
these episodes.
Speaker 2 (12:24):
Okay, so even if I did try to incorporate some
tea into my daily routine, it would not be equivalent
to drinking the same volume of coffee.
Speaker 1 (12:36):
Yes, that seems to be the case. Now that being said,
there are so many ways to prepare tea, and certainly
you could drink enough tea, you could drink those six
fresh steeps of tea and risk of transporting yourself to
the mystic mountain. So it's always always a possibility. And
everybody's different, you know, And I think our relationship with
caffeine does change as we age, so naturally, yeah, you
(12:57):
don't have to be a total tea nerd or immerged
to any degree within an Eastern culture of tea to
be into TV, because tea has spread around the globe
by this point. Tea culture now encompasses everything from British
high tea to Southern sweet iced tea, Taiwanese bubble tea,
to things like Senegaluese tea and their Tibetan tea preparation
(13:22):
methods that are also rather distinct. And again we'll come
back to some examples of these later on. But I
thought an interesting place to start might be too. Instead
of starting with the familiar or even anything in the
actual real world, we might start off by getting into
the mythological origins of tea. Even before we get into
(13:43):
the botanical realities of tea, we might start in just
purely mythic and I think mostly Chinese mythological origins for
this splendid beverage.
Speaker 2 (13:53):
Oh wait a minute, Wait a minute. If we're getting
into a myth about a psychoactive substance and its ancient
Chinese myth, are we going to meet the divine farmer
once again?
Speaker 1 (14:04):
Yes, yes we will, because of course, if it involves
something that you should eat or shouldn't eat, and is
a plan of some sort, then yeah, the divine farmer
Shinong has to show.
Speaker 2 (14:16):
Up Shinong putting things in his mouth for everybody's benefit.
Speaker 1 (14:20):
That's right. Yes, we've talked about Shinong before on the show.
He's a pretty important figure in Chinese mythology and he's
tied to myths concerning various botanical substances. His name literally
means divine farmer. He's a culture bearer, a god. He's
attributed with the invention of agriculture and the introduction of
(14:41):
agriculture to human beings. He's an important name in Chinese medicine.
He's said to have invented various farm tools and musical instruments,
So there's a lot that this mythological figure is attributed with.
And you know, obviously as a mythological figure, he is
sort of summing up and condensing a lot of the
things that actual human beings did over the course of generations.
(15:05):
Figuring out which plant has a medicinal property or seems
to which plant is good to eat, which plant will
kill you, that sort of thing. You should definitely look
up some images of him, because he's He's often depicted
as this kind of squat older man with bovine or
ox like characteristics, often kind of wide set eyes, and
(15:27):
even one of my favorite things about him is he
often has these kind of nub like horns. Now I
have seen depictions I think these are more modern, but
it could be wrong where he has like full blown
horns like a hornet deity. But generally it's these kind
of nubs where he looks just again, very very bovine.
Speaker 2 (15:44):
Would you call them buds? Are those called buds?
Speaker 1 (15:47):
Yeah? They kind of look like like buds. Yeah, Like,
if you don't know what you're looking at, you might say, well,
why does that man have two bumps on his head?
And it's because it's invoking this kind of ox like characteristics,
a character stick of the character. And in some tales
he was said to have had the head of a dragon,
others the head of an ox. And so we do
(16:08):
have to remember that he is a god, of course,
so it's natural that he might have some qualities like this.
There are various tales about his birth, including some traditions
that relate his incredible rate of maturity. One version said
that he could talk at three days old, he had
all of his teeth, etc. And in some accounts his
(16:29):
father was an actual dragon.
Speaker 2 (16:31):
Wait when you said had all of his teeth, you
meant he was like born with all of his teeth,
or he had all of his teeth when he was
three days old.
Speaker 1 (16:37):
His memory serves, and I believe this is related in
the book Chinese Mythology by yang An and Turner, there's
tales that's like, all right, at three days he had this,
At four days he had this. So he's just maturing
at a rapid rate, where at like three months old
he knows everything about agriculture and he's able to teach
it to humanity. Okay, but the basic story with Shin
(17:00):
own concerning plants is that he not only gave humans
the knowledge of agriculture, he also sussed out which plants
were useful in medicine and which ones were food, and
also which ones were poison And he did this, of course,
by testing them all himself. In some tellings, he's not
actually eating them. He's thrashing them with a reddish brown whip,
(17:22):
like a whip that is. And there's a lot you
can get into with the symbolism of it. I've seen
that it's there's something to it that this is kind
of the color of dried blood. Other times he has
a cauldron. So yeah. In some cases he says to
have some tools that he's using. But in many tellings
and certainly many artistic interpretations, he's testing all these various
(17:43):
botanicals out by eating them, and then afterwards he passes judgment.
He's okay, this this is a plant that would be
good for medicine, so I'm going to put it into
my right hand bag. This one is good for food,
so it's going into my left hand bag, and he
sorts it generally like that.
Speaker 2 (17:59):
What about the one that are poisonous.
Speaker 1 (18:03):
There's one tale where if something's poisonous, he just wants
to stop it, Like, I think there's a story that's
related about Ginger, where originally Ginger was said to be
poisonous and Shinong took a look at each he like
he checked it out and he's like, yeah, this is horrible.
I want to stomp on it as well. And then
Ginger had to change in order to be accepted, and
(18:24):
that's when Ginger went underground. Oh beautiful. Yeah, so yeah,
I want to explore that one more at some point
because I don't really understand all the meaning going on there,
but it's it's it's interesting now. I don't know if
we've talked about this version of the story with Shinong before,
but as Yang'an and Turner point out, in Chinese mythology,
some versions also state that Shinnong is particularly good at
(18:48):
figuring all of this out because he has a crystal
stomach and he can see everything that's going on inside
of his own internal organs as he's digesting things.
Speaker 2 (19:00):
It's like top ar. They open up his stomach and
they can look inside and see it see all the
parts working.
Speaker 1 (19:06):
Yeah, yeah, I just I love it. I definitely picture
this as kind of like almost some sort of an
android body that he has going on underneath his robes
here that he can pull it up, and yeah, it's
just crystal organs under crystal skin, and he can observe
every little detail going on in digestion. So in some
versions of the story, the first plant he was said
(19:28):
to taste was a green leaf, which once he put
it in his mouth and swallowed it, it went on
a grand tour of his insides, cleaning up everything along
the way, and again crystal stomach, so he gets to
watch it go.
Speaker 2 (19:41):
Okay, So it's kind of like a dryer sheet or something.
Speaker 1 (19:44):
Yeah, yeah, I guess. This particular plant was referred to
as cha, which means to inspect, which eventually got confused
in later tellings with cha, which is the exact same
phonetic sound but a different Chinese character. So the story
becomes later on that Shinong was poisoning himself upwards of
(20:08):
seventy times a day, testing out the world's plants to
determine which ones we could use for various purposes, and
if something got on top of him he got some
poison going around in his system, he would turn to
the cleansing power of tea to detoxify himself.
Speaker 2 (20:23):
Oh so, by the way, you should not derive actual
use value from that. But yeah, so in this version
of the story, T is like a universal antidote, right.
Speaker 1 (20:34):
And my understanding too is that older versions of the
story are not referring to T, but it becomes Tea
and later tellings of the story though this eventually catches
up with him. I was reading in that book that
one day he is said to have tried a yellow flower,
(20:54):
and upon trying the yellow flower, it broke his intestines
into pieces. He sees this through his stomach, his crystal stomach.
This occurs just the moment he swallows it, and he's
quickly trying to, you know, get himself some tea so
he can cleanse everything up, but it is too late.
He dies, and the plant that does this to him
(21:16):
becomes known as the intestine breaking weed.
Speaker 2 (21:20):
That is brutal in so many ways, especially because it
imagines the intestines as brittle rather than elastic. I mean,
I guess you could think of them that way.
Speaker 1 (21:33):
Well again, it makes me personally think of Shinong's crystal
organs as being like glass. And then the shattering is
kind of like when a cartoon character bites on something
that's too hard, and their teeth do that cartoon shattering thing.
That's what I picture in my mind happening to Shinong
here portion on. Yeah. Now there's a book, Shinong's Herbal Classic,
(22:05):
a later Han dynasty book that includes a great deal
of knowledge related to various botanical substances, and this book
is attributed to Shinong, likely based on oral traditions. It
includes a passage on tea, telling us that it's bitter
and share some details about when, how and where it
grows best. But as Laura C. Martin points out in
(22:26):
a History of Ta, references to T in this book
were probably not original to it, as the character for
Ta itself didn't come into usage until seventh century. But
more on the timeline of tea in a bit, because
we're still for now in the mythic.
Speaker 2 (22:41):
Timeline, okay, But talking about this book attributed to Shinong,
the idea is that probably there were earlier versions of
the book that did not have the tea passages, and
in recopying through the year's tea passages were inserted by
some editor or copyist exactly.
Speaker 1 (22:57):
Yes, Now, there are a couple of other tea related
myths here. This is one that Young Haan Turner point out.
It's a creation myth of the Dang ethnic people known
outside of China as the Palolang people in Unan Province.
And it's said that in this creation myth, one hundred
and two tea leaves went around and around in the
(23:19):
air for thirty thousand years and then transformed into fifty
one young men and fifty one young women. That's the
beginning of humanity. Now there's another one. This is a
This is a tea myth that largely emerges from India
rather than China. As Martin points out, the early history
of tea centers around China. But the plant is indigenous
(23:40):
to the Assam region of India in addition to southwestern China.
Yet it seems that it was a little known or
used in India prior to the sixth century.
Speaker 2 (23:48):
Seat and if you don't know where it is, Assam
is located in northeastern India. So the area of origin
for the tea plant, we think is basically southwestern China
northeastern India.
Speaker 1 (24:01):
Yeah. Yeah, though it does seem like it was better
known in China as opposed to India. But of course
we see a fair amount of cultural exchange between India
and China, and of course the most famous example of
this is of course Buddhism, and this particular story does
(24:22):
involve Buddhism as well. It's the story of Bodhidharma, who
was a fifth century semi legendary Indian prince who, much
like the Buddha himself a thousand years earlier, came to
see the emptiness of wealth and abandoned all of it
in the quest for enlightenment. He became a Buddhist monk,
and after many years of study, he travels to China
(24:43):
to reintroduce Buddhism and found Buddhism had been introduced into
China previously, but this most period where maybe it was
waning a bit, and he said to end up becoming
the founder of Chan Buddhism in the process. But while
he's in China, after visiting the emperor on this trip,
he retreated. He eats to a shovelin temple and here
he begins a long period of devoted meditation and asceticism.
(25:08):
So depending on the tail, and again there are different
versions with this. With most of these stories, he either
stares at a wall for nine years in meditation, or
he gives up sleep for nine years so that he
can really double down on his meditation. In one version
of this story, he grows so sleepy that he reaches
out and he grabs a leaf, like a random leaf,
(25:29):
and he just shoves it in his mouth to chew
it as a way to perk himself up. And his
luck would have it, this plant is tee and it
really does perk him up because it we'll discuss it
a bit, it contains a stimulant. There's another version of
this tale, and this one I got in trouble for
sharing at the Venner table in my post research excitement.
But in this other version, he's getting sleepy and he
(25:53):
pulls off his own eyelids because it's like, oh, heavy eyelids,
they keep shutting. I'm trying to meditate, but I keep
falling asleep. So he just pulls the eyelids off, throws
them on the ground, and then a tea plant grows
from where the eyelids fall. So, in either case, according
to this legendary account, he discovers tea and passes it
(26:16):
on to the other monks to assist them in their meditation.
All right, So there's just a taste of some of
the mythological stories involving the origin of ta, this spectacular
plant that is either discovered or perhaps even created out
of some sort of inspired inside by a legendary or
semi legendary individual.
Speaker 2 (26:37):
Now, when it comes to the T plant itself, there
were a few things that I actually did not know
until recently. I don't know if I should be embarrassed
about not knowing these, but I was just pretty much
in the dark about tea. But one thing I discovered
was that, apart from the issue of things being called
tea just actually being an infusion of anything, even when
you're talking about the T plant itself. Previously thought that
(27:01):
the main varieties of tea you hear about, like green
tea and black tea or maybe oolong tea, were from
different plants. But actually these are all from the same
plant as far as I can tell. They're just different
preparation and curing methods. Correct.
Speaker 1 (27:18):
Yeah, yeah, they're essentially we're talking about one single species
of plant. Camellia senensuss Camellia sinensus is an evergreen shrub
or tree, and you know Asterix there, we'll get to
that that produces small white petaled flowers. In the wild,
it will eventually reach tree size, but in situations where
(27:41):
it's been cultivated, generally they're kept at a shrub size
via pruning. They're typically kept at like a meter or
three feet in height, as that's an ideal height for picking.
Speaker 2 (27:53):
Yeah, and so you have these top layers of leaves
that come out, and I think they refer to those
as flushes, like the leaves keep protruding and then the
top young leaves are harvested.
Speaker 1 (28:04):
Yeah, and while we're essentially talking about one species, there
are two varieties. There's Camillias Andensus. This is the one
that's indigenous to western Yunnan in China. And then there's
a variety of that Camillia Senensus issamica. This is indigenous
to the Assam region of India as well as parts
of Myanmar, Thailand, Laos, Cambodia, Vietnam, and southern China. Now,
(28:28):
these two varieties they cross pollinate easily, so they are
also blends of the two. But Martin stresses that they're
actually not that different in taste either. So the varying
tastes and colors of different teas they stem from the
way we process them, whether you're talking about black or
green oolong, et cetera. And so either variety of tea
(28:49):
leaf processed the same way will basically be similar. But
at the same time, we don't want to discount traditions
surrounding particular teas. It's one of those things. It's kind
of like, you know, wine tastes or any kind of
like cultural food tradition. There's a lot tied up in
knowing where something comes from as well, and some of
(29:10):
that translates into the taste for the average consumer. Sometimes
it's something that translates into the connoisseur's taste experience, and
sometimes you're getting into an area where yes, you're being
primed that this particular I don't know, you know, this
wine stems from this vintage versus this vintage, this winery
(29:32):
versus this winery, etc. Yeah.
Speaker 2 (29:34):
Yeah, I mean, I think there are a lot of
different foods that maybe you actually couldn't tell the difference
in a blind taste test. But then again, it might
be cool to enjoy an authentic version of something knowing
the history behind it, like knowing where it comes from
and being able to think about that and so forth.
Speaker 1 (29:52):
Exactly so in the wild, tea plants are generally going
to thrive in an open woodland area or on the
edge of the woodlands where they can benefit from the
shade of larger trees. As such, when cultivating tea plants,
they're generally grown alongside shade trees. These, as Martin points out,
(30:12):
not only provide shade, but also it keeps weeds away
and enriches the soil and generally the leaves and the
buds or what are harvested fresh leaves generally contain about
four percent caffeine.
Speaker 2 (30:25):
I'm reading, and I was wondering about this because I
had read that it is maybe we can get more
into this when we do some of the cultural history.
But I have read that tea leaves were traditionally treated
as a food plant in China, more so than a
beverage plant, and the beverage stage came later. And so
(30:46):
apparently you can eat tea leaves. You can just prepare
them like a green and chew them up and eat them.
People do this sometimes and it's fine, though you need
to be careful about how much you eat, obviously, because
you don't want to overdose yourself.
Speaker 1 (30:59):
On caffeine right right, because most of us don't have
crystal clear guts that we can look at and to
determine what's happening, you know, by the moment. But yeah,
that'll be fun to get into in a subsequent episode.
The history of tea as a beverage is also the
history of a food, so yeah, I'm looking forward to that.
(31:29):
But coming back to the caffeine, this is a question
that applies of course to tea, but also to other
caffeinated beverages, or at least ones that have a natural origin,
Like why is there caffeine in the leaf? Like what
is there? Well, why is that substance that, for us
humans is a stimulant that kind of manipulates us as
(31:51):
a consumer of the plant, Like why is it even there?
Speaker 2 (31:54):
To begin with great question, So as a jumping off
point to answer this, I want to refer to an
article I was reading on the subject by previous show
guest Carl Zimmer, who is one of our favorite science writers.
He's been a guest on the podcast before. Maybe we'll
get him back again someday, but he came on to
talk about his book on genes and heredity called She
(32:15):
Has Her Mother's Laugh, which is a fantastic book. And
so Carl Zimmer had an article in twenty fourteen in
The New York Times called how Caffeine Evolved to help
plants survive and help people wake up? And he begins
by pointing out some rough stats about the popularity and
power of coffee and caffeine, saying the world consumes roughly
twenty six thousand cups of coffee per second. That's a lot.
(32:37):
That caffeine is probably the most widely used psychoactive substance
in the world. But there's an interesting thing about caffeine,
which is that it has a number of different associated
plants that it comes from. So, for example, there are
coffee beans. Coffee Beans are the seeds of a genus
of flowering plant called Caffea or Coffea in the family rubiaishi.
(33:03):
These plants are native to tropical Africa and tropical Asia.
There is of course tea. Tea again is made from
the leaves of the evergreen shrub Camillias and ensus, which
is native to East Asia. There's mate made from the
urbamate plant, which is a holly shrub native to South
America scientific name Ilex paraguariensis. And then you've even got chocolate.
(33:25):
Chocolate also contains caffeine. Chocolate's made from the seeds of
the cacao tree or theobroma cacao. Theobroma, by the way,
means food of the gods. Theo roma and historically was
not always used as an ingredient in sweets and desserts.
The main way we in the United States consume it today.
It was often consumed as a bitter, hot, or cold beverage,
(33:48):
kind of similar to how we consume coffee, which of
course would have carried a punch of caffeine, and chocolate
does have caffeine.
Speaker 1 (33:55):
I think our Invention episode where we talk to Jeff
Beach Bomberry, we talked a little bit about ancient recipes
for hot chocolate.
Speaker 2 (34:05):
Essentially, But it's kind of interesting to look at this
geographic distribution and say, how do all of these different
plants that are not closely related to one another independently
make this same compound. We know why humans like caffeine,
but what does caffeine do for the plants, and how
(34:27):
did all these diverse different species evolve to make it?
Speaker 1 (34:30):
Well.
Speaker 2 (34:30):
This article looks at a study published in the journal
Science in twenty fourteen, where researchers detailed an effort to
sequence the genome of a species of coffee plant responsible
for many of the world's coffee beans. This remember, coffee
comes from the genus Coffea or coffea, and this is
Coffea canaphora. The study is by France. Oh, I do
(34:53):
not know how to pronounce this last name, Deneud is
how the name is spelled at all, and the title
is the coffee genome provides insight into the convergent evolution
of caffeine biosynthesis. Again, that's in the journal Science twenty fourteen.
So one thing this study looked at is how caffeine
is actually synthesized in coffee plants. And it turns out
(35:16):
it is a multi stage transformation of molecule that it
begins with a compound called xanthozine, and the coffee plant
manufactures several enzymes that act on this compound. So one
enzyme removes an arm of the molecule, another enzyme adds
a new arm, Two more enzymes come in and add
two more clusters of atoms, and after all these transformations,
(35:39):
you finally have transformed xanthezine into caffeine, and the enzymes
involved in this multi step transformation are called in methyl transferases.
They are found in all plants, and they do generally
this sort of work, building specific compounds, many of which
plants use to defend themselves against predator or parasites. And
(36:02):
one example of a compound manufactured with the help of
in methyl transferases that zimbercites in the article is salicylic acid,
which is a compound produced by willow trees, which actually
turns out to be a potent pain reliever in animals
like us. Salicilic acid is the chemical basis for aspirin.
But what about the enzymes that manufacture caffeine specifically in coffee. Well,
(36:27):
the authors determine that some time ago, in the evolution
of the coffee plant, a gene for creating one type
of in methyl transfer enzyme underwent a series of mutations
to produce a variety of enzymes which would eventually create caffeine.
And so one of the co authors is quoted in
Carl Zimber's articles. This is by Victor A. Albert saying
(36:50):
they're all descendants of a common ancestor enzyme that started
screwing around with xanthezene compounds, So the plants are just
kind of like doing all these little variations on this
originator molecule and producing these derivative molecules that in many
cases are physiologically active or psychoactive on animals. And it
turns out scientists had already discovered that caffeine was created
(37:13):
by the action of in methyl transferrass in cocaw trees
and in the tea plant, so similar molecular frameworks are
going on within coffee plants, within the tree that makes
chocolate or cocow, and within tea plants. However, the researchers
also found that the enzymes for making caffeine in these
(37:35):
different plants did not all evolve from the same ancestors.
So this would be a case of convergent evolution, different
branches on the tree of life evolving the same solution,
the same phenotype independently. So you can think of a
million different examples of this. One is wings. Birds and
bees both evolved flapping wings independently for flight. They didn't
(37:58):
get them from a common ancestor that had wings. They
know their last common ancestor did not have wings, and
they independently, separately came up with the same solution. Now,
when you see convergent evolution, you see different streams of
evolution converging on the same trait or the same solution
to an environmental problem. It's usually a sign that that
(38:19):
trait or solution is pretty good. It's a powerful adaptation,
and there's a big survival and reproduction payoff. So it
would seem, based on the evidence of convergent evolution, that
producing caffeine is definitely good for something for the plants.
So what is it really good for. Well, there are
a few things we can talk about. One is activity
in poisoning or deterring predation by insects. So, like so
(38:43):
many of the plant based compounds that humans ingest on
purpose for their psychoactive properties, caffeine seems to be at
least in part useful for deterring predation by insects. Insects
would of course naturally like to eat the leaves and
the seeds of the cope plant, but high levels of
caffeine are toxic to them, and this relationship can be
(39:05):
seen further in the fact that the fruit fly Drosophila
drosophala has the ability to taste the presence of certain compounds.
I was reading about how they have an array of
at least sixty eight known These are called seven transmembrane
goostatory receptors or goustatory receptors are grs and goustatory meaning taste.
(39:27):
So these goustatory receptors allow the fly to sense the
presence of compounds that could kill it or harm it
and avoid eating them. Caffeine is one of those compounds.
Fruit Flies appear to have a suite of receptors, including
one called g R sixty six A, that work together
to sense the presence of caffeine in whatever they're eating
(39:49):
and allow an avoidance response to take over. Now, I
think it's interesting to put that together with the fact
that in the human experience, most alkaloids taste. Bitter. Alkaloids
are a broad class of nitrogen bearing organic compounds that
plants make, many of which have physiological effects on humans
(40:11):
and other animals, effects ranging from you know, all your
standard types of poisoning and death to psychoactive effects such
as the stimulant effect of caffeine. So bitter taste often
causes animals to reject a food source. So I think
it's kind of reasonable to put all this together in
wonder if the sensation of bitterness when ingesting plants rich
(40:32):
in alkaloids is perhaps a protective response that tells us
to stop consuming these plants and reject them, similar in
effect to the way that a fruitfly has the ability
to taste and reject caffeine, though with a different evolutionary backstory.
Speaker 1 (40:47):
Yeah, that's a good point. I mean, it makes me
think of, you know, the obvious of example of say
a child being introduced to coffee and finding it disgusting
because it is bitter. And also we have to think
about the fact that that the chocolate unsweeten has a
very bitter taste to it as well, though of course
in both cases coffee and chocolate, there is of course
(41:09):
a process involved here we're not going to really get
into with coffee and chocolate between plant and even the
unsweetened food product, but that's something we can come back
to in the future. I love to do something on chocolate,
say in the future.
Speaker 2 (41:25):
Absolutely, And yeah, it's interesting to think about the complex
human reaction or response to bitterness that it seems bitterness
is probably primarily biologically relevant in getting us to reject foods.
You know, it's like this has something in it that
I don't want to get too much of, So I
probably don't want to eat too much of this.
Speaker 1 (41:42):
Yeah. So many of the naturally occurring pesticides that we consume, Yeah,
they have some sort of a strong flavor that would
tend to convince most humans to avoid them, certainly, and
in many of the cases where there are various spices,
avoid them in larger quantities than we traditionally use them.
Speaker 2 (42:00):
And yet we can really get a taste for them.
I mean, I like the bitter taste of coffee and
of chocolate and of tea and so forth. It might
have to do with like it's a level of bitterness
that doesn't reach kind of a threshold which you would
find it disgusting, like it's like below the bar for rejection.
Or it could be a totally it could be a
(42:21):
learned response. I mean maybe naturally people don't like bitter
stuff in any quantity, but if culturally they learn to
appreciate it, I don't know, maybe maybe that's what's making
the difference there.
Speaker 1 (42:32):
Oh well, I mean in cocktail culture, for example, you
have a you know, a whole spectrum of bitter drinks.
You know, sometimes you're just adding a little bitter taste
via bitters in many cases, to to offset sweetness and
give you a certain flavor profile. But some people go
especially hard for those those bitter drinks. They're like, I've
(42:54):
never tried one of these, but you have these recipes
floating around for mixed drinks that contain like multiple bitter
components to try and create like some sort of uber
bitter concoction, which is not for me, but I assume
it's for some people who have developed a taste for
all of those bitter components.
Speaker 2 (43:14):
Well, I mean, I do think about how many of
the bitter food almost all of the really enjoyable bitter
foods and beverages I can think of or psychoactive in
one way or another. I mean, I guess not like
you know, bitter greens or something. You know, I like
greens that can be bitter, but I think of coffee,
which has caffeine. I think of chocolate, which has caffeine.
I think of tea, which has caffeine. Or I think
(43:36):
of alcoholic beverages that are bitter, like you know, like
hoppy beers and so forth.
Speaker 1 (43:41):
Yeah, so it's almost like on some level, our bodies
saying this tastes bad, but something good is happening.
Speaker 4 (43:47):
Yeah, but okay, So caffeine, one of it rolls within
a plant might be to deter insects or other animals,
maybe from eating the leaves of the plant.
Speaker 2 (44:06):
They got enough caffeine in there. One way or another,
the toxicity of the caffeine will drive the animal away.
Another interesting idea that Zimmer raises in this article is
that caffeine in coffee plants is suspected to work also
by inhibiting the growth and germination of other plants. He
writes that when coffee leaves die and fall off of
(44:29):
a coffee plant, they fall down to the soil below.
The caffeine content seeps into the earth and interferes with
the ability of other plant species in the soil nearby
to germinate. So this helps limit competition for soil resources
and sunlight in the area. Now, I didn't find anything
specifically about whether or not that's true with tea plants
(44:49):
as well, but it could also be the case if
it works for the coffee plant. But one thing where
I did find a parallel between how they think caffeine
is working in coffee plants and tea plants is its
role in pollination. I thought this was the most interesting
of all. So, in addition to deterring insect or animal
predation and perhaps limiting competition from nearby plants, the psychoactive
(45:14):
and drug like properties of caffeine on animals might be
not only an unintended byproduct or side effect of their
physiological activity as a deterrent. They might actually be in
part the point of the compound, or at least one
of the points of the compound, and it would work
like this So coffee and flowering plants that produce caffeine
(45:37):
in their leaves also produce lower doses of caffeine in
their nectar. Now, plants make nectar as a food for
insects as an incentive for insects to spread their pollen.
So the insect gets sugar from the plant, it gets
a meal, and the plant gets help with reproduction and
(45:58):
dispersal when returning it's help spreading its genetic material. Now
here's the really interesting thing. Research has shown that when
insects feed on plant nectar containing low doses of caffeine,
they seem to become more disposed to remember the scent
of the flower where they consumed that nectar, and researchers
(46:20):
believe this may cause the insect to return to that
flower more often and thus spread its pollen more effectively.
So maybe out of just one compound, this one molecule
that the plant creates, it can be getting multiple completely
different effects depending on the dosage in the different part
of the plant. So maybe higher levels in the leaves
(46:41):
will deter insects from trying to eat the leaves, but
lower levels in the nectar will be more like a
cup of coffee for the insect, which boosts the insect's
memory and allows it to return to the same plant
more frequently and spread that plant's genetic material. Toxic and
high concentration, but beneficial to some types of brain function
(47:04):
at lower doses. And it's funny that caffeine has the
same dual effect on humans. I mean, if you have
too much of it, it will kill you. But if
you have these low doses of it that people consume
in beverages and stuff, people use it directly as a
stimulant to improve their brain function.
Speaker 1 (47:20):
Yeah, I mean, coming back to Shinong, the mythical story here,
it's basically an individual god figuring out to what degree
one should consume the world of poisons around us, how
much of this poison is appropriate for desired outcome, and
then which poisons should we not mess with at all?
Speaker 2 (47:40):
Exactly? So I found this so interesting. But anyway, this
was all about the coffee plant. I was trying to
find is the same thing true of the T plant,
And I did, in fact find. A study from just
a couple of years ago is from twenty twenty one
published in the Journal of Insect Physiology. It was by
Gwen Gong at All and it was called Laurel T
(48:00):
polyphenols can improve honeybee memory retention and olfactory sensitivity. So
the background on the study is to read from their
abstract quote. Animal pollinated plants face a common problem how
their defensive anti herbivore compounds may impair or alter pollinator behavior.
Evolution has tailored multiple solutions, which largely involve pollinator tolerance
(48:25):
or manipulation to the benefit of the plant, not the
removal of these compounds from pollen or nectar. The T
plant Camilli s. Senensis is famous for the caffeine and
T polyphenols that it produces in its leaves. However, these
compounds are also found in its nectar, which honeybees readily collect.
(48:45):
So to summarize here, the authors tested the effects of
these two different products of the tea plant, of the
caffeine and the T polyphenols, and they tested it on
the forging behavior of honeybees. And what they say they
found is that honeybees preferred simulated nectar from a feeder
when it contained T polyphenols over a control feeder that
(49:07):
did not contain them. And they also found that bees
that were fed on a feeder laced with caffeine showed
small improvements in learning. Both caffeine and T polyphenols increased
memory retention and showed influences on other behaviors as well,
such as response to alarm pheromones. So it seems that
the T plant may well be adapted to give pollinating
(49:29):
insects small doses of caffeine and T polyphenols for a reason.
It could mean, among other things, that the pollinating insects
are more likely to keep returning to the same plant
and spreading its genetic material. And I thought this was
so interesting. So if this is in fact the case,
it's a more complex relationship than I usually imagine between
(49:51):
plants and the alkaloids that they manufacture and the animals
that they target, because I usually think of the relationship
as a pretty simple one way way interaction, like the
plant alkaloid causes some kind of negative physiological response or
reaction in the animal, and then the animal is deterred
from eating the plant again, or the animal is driven
(50:12):
to evolve like gustatory receptors or taste that make the
plant taste nasty from the first spite, because you know,
it's ancestors that didn't have that may have died. But
this is a more complex implied relationship. I don't know
exactly what to compare it to. I mean, it's almost
like the cultivating of an analog of an addiction, but
one with I don't know, survival benefits for the bee
(50:36):
as well, because it allows them to keep returning to
a food source.
Speaker 1 (50:40):
So before we got into all this here, if I
were put to the test, I would have just said, well,
caffeine implants is just about keeping some things from eating them,
and we've managed to manipulate that situation for our own benefit.
But yeah, it sounds like the reality is a lot
more complicated. Of course, you can't really think about purpose
and design and desire in the literal sense when it
(51:02):
comes to the evolution of something like this in various
plant species. But I am kind of reminded of how
some products in the human world will end up with
more than one purpose, Like, for instance, I think of
bag bomb. Have you ever used bag bomb or seen
a container of bag bomb?
Speaker 2 (51:19):
I don't think so. Explain.
Speaker 1 (51:21):
It's like a little greenkin and I believe it dates
back to her about eighteen ninety nine, and it was
it's a salve to put on a cow's udders after milking.
But people started using it because they realized that, hey,
you can put this on dry cracked skin. And so
it's one of these things where it ended up being
there's this whole additional application of the product, an entire
(51:44):
different consumer base that kind of sprang out of it.
It's more complicated, obviously with the case with caffeine and plants,
but it's almost it almost feels like that where there
may be one purpose that's kind of driving the evolution
of this, but then this other use, the other way
that it can enhance the survivability of the plant emerges
(52:06):
as well, and so you have these sort of dual
forces driving it at that point.
Speaker 2 (52:11):
Oh yeah, Evolution loves to repurpose pre existing morphologies, So
like a structure or a chemical capacity, or something that
evolved initially for one reason can always be repurposed when
a new opportunity presents itself. Yeah, and I don't know
specifically what the order would have been in any of
these cases, whether you're talking about coffee plants or tea plants,
(52:33):
but you can imagine a compound. Initially, there is evolutionary
pressure favoring the enzymes to produce that compound because it
I don't know, because it deters predation by animals, or
because it limits competition when the leaves fall into the soil.
And then later something like this relationship with pollinators emerges
using the same compound.
Speaker 1 (52:51):
And then eventually this relationship with human beings who start
cultivating it. So it's fascinating to think about all of
these relationships. All Right, we're gonna go ahead and wrap
up this episode, but we'll be back in the next
episode with more discussion of tea. In the meantime, of course,
we'd love to hear from everyone out there. You might
be thinking to yourself, well, I have some tidbit I
(53:13):
want to share about tea, but surely Robert and Joe
don't want to hear it. No, we want to hear
it right in. We want to know about your individual
or cultural differences and appetite for tea. If there are
other myths or legends or folk tales that you've heard
about about the origins of tea, write in. We would
love to hear from you. In the meantime, will remind
(53:35):
you that Stuff to Blow Your Mind is primarily a
science podcast, with core episodes on Tuesdays and Thursdays. On
Mondays we do listener mail. That's that's when we will
read the messages that come in about these episodes. On
Wednesdays we do a short form artifact or monster fact episode,
and then on Fridays it's Weird House Cinema time. That's
when we set aside most serious concerns and just talk
(53:56):
about a strange film.
Speaker 2 (53:57):
Huge thanks to our audio producer JJ Pauseway. If you
would like to get in touch with us with feedback
on this episode or any other, to suggest a topic
for the future, or just to say hello, you can
email us at contact at stuff to Blow your Mind
dot com.
Speaker 3 (54:19):
Stuff to Blow your Mind is production of iHeartRadio. For
more podcasts from iHeartRadio, visit the iHeartRadio app, Apple podcasts,
or wherever you're listening to your favorite shows.
Stuff To Blow Your Mind News
Hosts And Creators
Robert Lamb
Joe McCormick
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