How Are Our Coffee Beans Decaffeinated?
Our Decaf beans start out in Narino, Colombia, and are processed so
that the outer layers (called the "cherry") are removed. After this processing but before being roasted, coffee beans are referred to as "greens". If coffee is going to be decaffeinated, the caffeine must be extracted after the beans have been processed. The greens are then sent to Germany to a decaffeination plant.
To be considered decaffeinated in the US, the coffee must have a
minimum of 97% of its caffeine removed. Since caffeine is
water-soluble, heat and water are used to remove the caffeine. The next
step is to separate the caffeine from all the other solubles - you
don't want to lose all of those great aromatics along with the
caffeine!
There are several different methods of decaffeination, all of which involve heat, water and a solvent. Solvents are substances capable of dissolving other substances. The most common chemical solvents used in decaffeination are methylene chloride and ethyl acetate, which can remove caffeine directly or indirectly. For our decaf, we buy and roast beans that have been decaffeinated by the methylene chloride, or MC method.
Using the MC method, our beans are decaffeinated directly, using the Direct Solvent process. Here's a run-down of how it works, taken from page 17 of our Barista Manual:
The Direct Solvent Process is considered to be less destructive to the taste of coffee than other methods. We've tasted a lot of decaf, and this process produces a better tasting cup again and again. Of course, any time you begin discussing chemicals, health concerns come into play, but in fact, methylene chloride becomes volatile (burns off) at 104 degrees F, while coffee reaches internal temperatures of over 400 degrees F during roasting. Even microscopic amounts of solvent residues would be burned off.
We only brew our Decaf Americano style, as a shot of espresso pulled over hot water, and we find this to be the best brew method. It produces a creamy body, savory nuttiness and notes of toasted pumpernickel.
Thanks to Mimi Wysong, manager of our Cayuga Street store, for these amazing pictures.
There are several different methods of decaffeination, all of which involve heat, water and a solvent. Solvents are substances capable of dissolving other substances. The most common chemical solvents used in decaffeination are methylene chloride and ethyl acetate, which can remove caffeine directly or indirectly. For our decaf, we buy and roast beans that have been decaffeinated by the methylene chloride, or MC method.
Using the MC method, our beans are decaffeinated directly, using the Direct Solvent process. Here's a run-down of how it works, taken from page 17 of our Barista Manual:
- The beans are steamed, causing them to swell, which opens up the
pores and dissolves the waxy coating without affecting the flavor of
the coffee inside the bean.
- The beans are put in contact with the solvent in a pressurized environment for a certain period of time.
- During this time, the solvent bonds to the caffeine molecules.
- The coffee beans are run through water and steam treatments, evaporating the caffeine-laden solvent out of the beans.
The Direct Solvent Process is considered to be less destructive to the taste of coffee than other methods. We've tasted a lot of decaf, and this process produces a better tasting cup again and again. Of course, any time you begin discussing chemicals, health concerns come into play, but in fact, methylene chloride becomes volatile (burns off) at 104 degrees F, while coffee reaches internal temperatures of over 400 degrees F during roasting. Even microscopic amounts of solvent residues would be burned off.
We only brew our Decaf Americano style, as a shot of espresso pulled over hot water, and we find this to be the best brew method. It produces a creamy body, savory nuttiness and notes of toasted pumpernickel.
Thanks to Mimi Wysong, manager of our Cayuga Street store, for these amazing pictures.
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