The Green Bag Story: Decaf Coffee (part 2)

Decaf Coffee is great for somebody who craves that fresh, bold, coffee flavor but doesn’t want the buzz associated with it. But how does it work? Coffee beans all grow with natural levels of caffeine, so we must extract it after the beans have been removed from the coffee cherry, but before roasting.

Some decaffeinating processes use a “decaffeinating agent” or “solvent” such as ethyl acetate, or methylene chloride at one stage in the decaffeinating process. (Don’t worry-- these agents are completely removed  from the green coffee beans, and in some cases, they never even touch the beans themselves. Even if the solvents remained on the beans, they evaporate at temperatures far lower than those found in a coffee roaster, so the solvents wouldn’t survive the roasting process.) These decaffeinating agents are used because water is not a particularly selective decaffeinating substance on its own. Water can, and does, wash away caffeine, but it can also remove sugars and proteins, which can potentially lend a “washed-out” flavor to the resulting coffee. We discussed the Water Process, which does not use any chemical solvents to decaffeinate coffee, in a previous article.

Solvent-Based decaffeinating processes can be split into two distinct methods. One, is a Direct method, where the decaffeinating agents are applied directly to the beans. The other, an Indirect method, has found a great deal of popularity in Europe (though it is also used elsewhere), and the beans do not come into contact with the decaffeinating agent itself.

We’ll look at the Indirect method in this article.

(Stay tuned for a future article on the Direct method of solvent-based decaffeinating.)

Green coffee beans are soaked in very hot (almost boiling) water for several hours in order to extract the caffeine from the beans. As in the Water Process, the hot water removes caffeine, as well as oils sugars, proteins and other elements that make up the complex flavor profile of the coffee bean.

The water is drained into a separate tank and a solvent (a decaffeinating agent) is added to the water. Often, Methylene Chloride is the chemical used in the indirect method. The caffeine bonds with the methylene chloride. The water is gently heated to aid in this process. The caffeine and solvent are then removed from the water, through a combination of skimming (the caffeine and solvent rise to the top of the water and is funneled out) and gentle heating to evaporate any remaining solvent and caffeine molecules.

Once the water, which still contains coffee flavor molecules and oils, has been decaffeinated, it is returned to the first tank, where the green decaffeinated beans are waiting. The coffee beans reabsorb most of the coffee oils and flavor and are then dried and ready for roasting!

We only select the finest quality decaffeinated coffees to roast here at Carrabassett Coffee Company. You won’t find a weak, washed-out flavor profile in your cup. Our coffees are all carefully selected and curated to suit a variety of tastes. We then roast in small batches to ensure peak freshness by the time it arrives at your door. Browse our selection of Non-Flavored Decaf Coffees, or,( if the thought of a flavored coffee without the buzz tickles your fancy,) you can find decaffeinated flavored coffees here.