How Science Saved Decaf: Coffee Chemistry 101 with Dr. Yoblinski

What really happens when coffee goes decaf? Discover the truth of the often-misunderstood world of decaffeination as we peel back the layers to reveal the surprising history and cutting-edge science that creates your favorite caffeine-free brew. Discover how decaf coffee went from using dangerous chemicals like benzene to today's revolutionary supercritical CO2 process. Our expert guest, Dr. BJ Yoblinski, an inorganic chemist, demystifies complex concepts, explaining what a supercritical fluid is and how it precisely extracts caffeine from green coffee beans. From early accidental discoveries to modern bean to cup innovation, this episode offers a fascinating look at the coffee science ensuring your decaf is both safe and delicious. Tune in to understand the intricate industrial process and the surprising fate of the extracted caffeine!

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5 Takeaways:

1. Early Decaf Was Risky: The very first decaffeination methods, including those used for Sanka, involved highly toxic chemicals like benzene (a component of paint stripper and gasoline).

2. Supercritical Fluids are "Fourth State" Wonders: Beyond solid, liquid, and gas, substances like CO2​ can become a "supercritical fluid" under specific temperature and pressure, exhibiting properties of both liquid and gas, making them ideal solvents.

3. CO2​ is a Selective Solvent: In its supercritical state, carbon dioxide preferentially dissolves caffeine from coffee beans, leaving the flavor compounds largely intact.

4. Modern Decaf is Safe & Clean: The widespread adoption of the supercritical CO2​ process replaced older, more dangerous chemical methods, leading to a safer and better-tasting decaf coffee.

5. Extracted Caffeine Has a New Life: The caffeine removed from decaf coffee beans is purified and primarily sold to the soft drink and power drink industries.

3 Discussion Questions :

1. Were you surprised to learn about the early decaffeination methods? What was the most shocking fact for you?

2. Had you ever heard of a "supercritical fluid" before this episode? How would you explain it to a friend now?

3. Do you drink decaf coffee? Does knowing the science behind the CO2​ process change your perception of it?

Glossary of Terms

• Atmosphere (atm): A unit of pressure, approximately equal to the average atmospheric pressure at sea level. In the context of decaffeination, high atmospheres of pressure are used to achieve a supercritical state.

• Benzene: An organic chemical compound, historically used in the early decaffeination process for Sanka. It is a known carcinogen (cancer-causing substance) and is also found in paint stripper and gasoline.

• Caffeine: A natural stimulant found in coffee beans, tea leaves, cocoa, and other plants. It is the primary target for removal in the decaffeination process.

• Carcinogen: Any substance, radionuclide, or radiation that promotes carcinogenesis (the formation of cancer). Benzene is identified as a carcinogen in the episode.

• Carbon Dioxide (CO2​): A colorless, odorless gas. In the supercritical CO2​ decaffeination process, it is transformed into a supercritical fluid to selectively extract caffeine.

• Critical Point: The specific temperature and pressure at which the distinction between liquid and gas phases disappears for a substance. Above this point, the substance exists as a supercritical fluid.

• Decaffeination: The process of removing caffeine from coffee beans.

• Degassing Chamber: A component in the industrial supercritical CO2​ decaffeination process where the pressure and temperature are lowered, causing the CO2​ to revert to a gas and leaving solid caffeine behind.

• Extractors (Continuous Extractors): Tall, industrial vessels (described as 60-70 feet high) used in the supercritical CO2​ process where green coffee beans are soaked in the supercritical CO2​ to dissolve the caffeine.

• Green Coffee Beans: Unroasted coffee beans, which are the starting material for the decaffeination process.

• Inorganic Chemistry: A branch of chemistry that deals with the properties and reactions of inorganic compounds (those not containing carbon-hydrogen bonds, or containing them in simple forms). Dr. BJ Yablinski's expertise is in th