The Science of Coffee

If you ask two specialty professionals what makes a high-quality coffee, you’ll likely get a surprisingly consistent answer: clean, sweet, juicy, bright. To an outsider, they would be forgiven for thinking coffee quality is universally defined.

But the truth is more sober.

In this episode, we examine how a simple cupping form helped create a universal idea of quality. We then look at the evidence that, in fact, it’s j...

For the longest time, coffees were dull and bitter. But then a small group of pioneers changed the world. 

In this episode, we travel back to the 1960s and ’70s to meet the trailblazers who realised coffees could taste distinctive: sweeter, brighter, cleaner. 

We discover how their personal preferences became a movement, then a form, and eventually a global definition of “quality”.

Please support my w...

For the longest time, the coffee community only cared about water’s impact ruining espresso machine boilers and kettles. But what about water’s impact on coffee flavour?

In this episode, I tell the story of how the specialty coffee community came to understand water chemistry: the pioneering work of the computational chemist Christopher Hendon and British roaster Maxwell Colonna-Dashwood, th...

550 million years ago, earth was perfect. We had perfect water for coffee AND we were living in a vegetarian paradise!

But then Earth changed—violently. The planet shifted from a peaceful, plant-eating paradise to a darker, more brutal world. And in this new world, the chemistry of water was forever altered.

This is the wild story of how earth-shaking forces and the spirits of long...

Water massively impacts your coffee’s flavours. But most of us struggle to fix our water because water science is confusing…

…until now! In this special collaboration with Lucia Solis (Making Coffee podcast), I guide her through the two most important concepts you need to understand to get great-tasting water for coffee: hardness and alkalinity.

We go step-by-step through:

• Why these concepts matter for coff...

Water massively impacts your coffee’s flavours. But most of us struggle to fix our water because water science is confusing…

…until now! In this special collaboration with Lucia Solis (Making Coffee podcast), I guide her through the two most important concepts you need to understand to get great-tasting water for coffee: hardness and alkalinity.

We go step-by-step through:

• Why these concepts matter for coff...

Every time we open a bag of beautiful specialty coffee — like Erick Bravo’s from Finca El Chaferote in Huila, Colombia — we’re drinking something that’s been on a long journey.

And I mean long! Over 1500 kilometers north up and down the Andes mountain range, a distance more than twice the height of France.

Along the way, it passes through dozens of hands, ma...

I travel to Colombia’s Huila region to answer a question that’s puzzled me for years: if specialty coffee pays more, is better for the environment, and brews tastier cups—why don’t more farmers grow it?

I speak with two producers in the same region whose choices couldn’t be more different. One stakes his future on specialty. The other opts out.

Their decisions come down to more than passion or a hard...

Volume. Cheap. Lame flavours. This is the traditional way of growing coffee in Brazil, and almost every farm does it this way. 

But what if you wanted to produce beautiful, distinctive flavours instead—and make a living from it?

In this episode, we travel to Fazenda Paraíso in Minas Gerais, Brazil, where farmer Vicente Pereira and his daughter are on a steep learning curve finding buyers for their beautiful coffees.&nb...

Volume. Cheap. Lame flavours. This is the traditional way of growing coffee in Brazil, and almost every farm does it this way. 

But what if you wanted to produce beautiful, distinctive flavours instead—and make a living from it?

In this episode, we travel to Fazenda Paraíso in Minas Gerais, Brazil, where farmer Vicente Pereira and his daughter are on a steep learning curve finding buyers for their beautiful coffees.&nb...

To roast coffee faster, you need to turn up the heat….right?

No! 

In this episode, we explore the three powerful methods of heat transfer that revolutionised roasting. We’ll journey from humble beginnings—when roasting three kilos took half an hour—to machines that now roast hundreds of kilos of coffee in the time it takes you to boil a kettle. 

But beans roasted at lightning speed look strange...

A mother coffee plant gifts its baby everything it needs to grow—a green seed packed with food. But when we roast coffee, we hijack that gift and turn it into something else: flavor.

But what is flavor, at a microscopic level? What actually happens inside the bean when heat meets those nutrients?

In this episode, we shrink down to witness the Maillard reaction up close—a wild chain of molecular collisions that transfo...

When I started making cold brew this last year, I treated it like hot brew filter coffee. But no matter how I adjusted the grind or tweaked the brew time, I hardly got any differences in flavor…

Then it hit me: cold brew isn’t just a slower hot brew—it’s a completely different game with its own rules!

In this episode, I speak with leading coffee researchers who break down the microscopic dance between wat...

For years, I used cold brew as a last resort—the only brew method to tame dark, oily beans that were too bitter for hot water. 

Then one day, I took a chance on a Guatemalan Gesha and brewed it cold. The result? A massive explosion of florals I’d never tasted before. That single cup sent opened my eyes into how extraordinary cold brew can be.

In this episode, I speak with world-leading coffee scientists who expla...

We’re back with another series of The Science of Coffee—and this time we’re diving even deeper into coffee’s hidden microscopic secrets!

Over the past year, narrative audio producer and coffee professional James Harper has scoured academic journals, ventured deep into coffee farms, and conducted bold tasting experiments.

Now, he’s weaving those discoveries into captivating audio stories that reveal w...

Deep inside your coffee grinder, tiny changes can have massive consequences.  This episode takes you deep inside Mahlkönig’s grinders to show you how coffee is ground and the importance of particle sizes on flavour.  If you’re a home coffee lover, you could easily spend thousands of dollars on your coffee grinder. But after diving deep into the R&D of grinder manufacturing, I learned that after a certain...

For your coffee to taste its best, it’s crucial you buy fresh roasts and grind fresh.… .….Or maybe not.  When I began creating this episode, I was convinced that ‘fresh is best’. But, after delving into the science of coffee freshness, I don’t believe that anymore.  This episode goes deep into how diffusion and oxidation changes a coffee’s flavours. You’ll learn what it...

In the last episode, I discovered that rinsing my Chemex filter papers was a waste of time! As a result I’ve managed to claw back over seven days of my life left on earth.  But why stop there?  The coffee industry is full of elaborate ways of brewing and savouring coffee: fancy drippers, cold metal balls, “slurp-able” cupping spoons. These are very fun, but how many of them actually affect the flavour...

Should you rinse your filter paper before making a filter coffee? Almost everybody in coffee internet says you should.  But what if most of coffee internet was wrong? In this episode, I show you how I try to answer this question like a professional sensory scientist would.  It’s hard. It’s frustrating. But ultimately, it’s worth it because I end up saving seven days of my life left on earth! Please ...