Decaf - How does it happen?
Decaffeinated coffee is not often a topic of conversation among coffee drinkers. On the occasion it is, it’s usually accompanied with jeers or judgment. Decaf coffee commonly has a negative connotation. You hear sentiments such as “death before decaf” or “what’s the point without caffeine?” To be fair, those criticisms have a bit of merit. Decaf coffee is typically a let down. However, when it receives the same care as other coffees, decaf coffee can be delicious! It also serves a noble purpose. Caffeine is a substance that is processed differently by each person’s body. Many people have a high sensitivity to caffeine and are resigned to decaf. Other times, you just deeply crave a cup of coffee… but it’s 10pm. As someone who loves the taste of coffee, I find myself in that scenario quite a bit. Still, there are barriers that remain for someone interested in drinking decaf. Two main questions arise: “How is coffee decaffeinated?” and “Is it safe?”
Decaf coffee starts off as any other coffee would. It is grown, harvested, processed, and shipped off. In this case, the coffee ends up at a decaf processing plant. These plants then put the raw coffee through one of three main decaffeinating methods: The Methylene Chloride/Dichloromethane Process, The Swiss Water Process, or the Sugarcane Ethyl Acetate process.
To oversimplify things, these processes all use the same basic steps. Step one is to steep or steam the coffee with water. This opens up the very dense coffee beans to chemical change by making them more porous. Step two is to add a solvent to grab on to the caffeine particles. Step three involves disposing and rinsing away the solvent. The difference between most methods comes down to the solvent used.
Methylene Chloride/Dichloromethane is a compound that can be dangerous in very high quantities and concentrations. However, the U.S. Environment Protection Agency has concluded that your exposure from drinking two whole pounds of this type of decaf coffee is comparable to the ambient exposure of one day of walking through a North American city.
The Swiss Water Process is a widely known process that uses a “green coffee extract” as a chemical-free solvent. Essentially, raw coffee is soaked in water, it removes the flavor and caffeine compounds, and the caffeine is removed from that extract with a carbon filtration system. That caffeine-free extract is then added into a fresh batch of raw coffee. The caffeine in the fresh coffee is no longer at equilibrium and is expelled out of the beans and into the extract. The caffeine is removed again, and we are left with raw coffee and its re-added flavor compounds.
Lastly, we are left with the method of decaf coffee we buy here at Tala, the Sugarcane Ethyl Acetate process. Ethyl acetate sounds like a scary chemical, but it’s actually an organic compound that comes from the fermentation of molasses derived from sugarcane. Ethyl acetate is added during the solvent phase of decaffeination. It binds to the caffeine particles and is washed away with the solvent. Because it is an organic compound, the ethyl acetate does not bind to the flavor compounds in the raw coffee, preserving flavor without using a damaging or potentially dangerous chemical.
One final, but important note. Decaffeinated coffee is not 100% caffeine free. All of these methods are very effective, but do not completely remove all of the caffeine. To be classified as decaf, caffeine is required to be not more than 0.3% of the final WEIGHT of the coffee. Caffeine starts off at roughly 1-2% of the weight of a coffee. Most of the caffeine is removed, but not all. You can expect to see roughly 4-10 milligrams of caffeine in a double shot of espresso from a well processed decaf coffee.
Whether you have a caffeine sensitivity, become pregnant, or just need that coffee fix without the caffeine, you can now rest easy knowing the uncovered mysteries of decaf coffee.
Mike Boyack
Barista and resident coffee nerd, Mike is always up for a conversation about coffee. When he’s not in the cafe, roastery, or training lab, he’s typically hanging out with his wife Kailyn and newborn son Bennett.
