Food

Jul 7 2009, 6:45 am

In Defense of Decaf

We have also cupped many samples that have been decaffeinated using either ethyl acetate or carbon dioxide (CO2). Neither method has consistently produced satisfying flavor in the cup. Ethyl acetate, a synthetic fruit ester, leaves a fruity aftertaste in the coffee--unfortunately nothing like the berry and citrus flavors we find in East African coffees. And we had high hopes for the CO2 process in the early '90s. Carbon dioxide is the carbonation in sparkling water, but it is forced into the coffee at pressures well in excess of 1000 pounds per square inch to extract the caffeine. Perhaps it's the pressure that also forces out the coffee flavor.

The last method to discuss is dihydro-oxide--water. At one time, water process was the most damaging to coffee flavor. That general statement is no longer true, due to improvements in the processing by some companies. Although some water-process decaf has flavor approaching methylene chloride (and a relatively new North American company is making great strides in cup quality), further development will be required before it can be methylene chloride's equal.

In general the process uses water as the solvent, supersaturated with soluble solids from green coffee beans, except caffeine. The idea is that when the warm solvent is circulated through the coffee, it will extract only caffeine, which in turn is removed from the circulating fluid with activated carbon. It's a thesis that in practice has not produced great cups of decaf.

The old standby water decaffeination company, Swiss Water (the only attempt to brand a process), of Vancouver, Canada, is doing all the advertising while others are improving their process. We prefer the cup quality of other companies, and I deplore the marketing tactics of Swiss Water.

In the late '80s, when I first wrote to the previous owners, I decried their deliberately misleading advertising. Here they go again. They are falling back into advertising tactics that assume the ignorance of the audience. Their attempt to associate the chemical names of the other processes with some chemo-hysteria is unethical.

To summarize, of the four major processes for decaf, only methylene chloride and water are widely used in specialty coffee (here, by the way, Wikipedia on decaffeination is less strong than it is on caffeine). Methylene chloride can produce the best cup results when good coffee and careful processing are used. Good coffee and careful processing also produce the best results from dihydro-oxide, but the best is still second in cup quality to MC.

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Comments (5)

What do you think about chicory and coffee-chicory blends? In addition to having no caffeine, a few minutes of googling suggest to me that chicory is a base, which seems to me would help coffee's acidity as well. (Well, my high school chemistry also suggests that there ought to be a precipitant forming from that, which I try not to think about.)

Jerry Baldwin

Whenever I visit New Orleans, I always have at least one cup of coffee with chicory--just to re-ground myself in the local culture. Although chicory is well established in Louisiana, the rest of the world recognizes it for what it is; namely, one more version of ersatz coffee. Other fillers used over the years are barley (as recently as the 1970s), oats, chickpeas, beets, acorns and whatever the deprived might have at hand. These substitutes may not have caffeine, but neither do they have coffee flavor, which regular readers will recognize as the raison d'etre of my efforts.

Barista de Casa

Good article. I've roasted both MC and Swiss Water, but definitely prefer MC even though I don't favor decaf. It's always good to have a supply on hand.

Brandon Gott
www.baristadecasa.com

Thanks for the excellent article -- especially for debunking the fears of methylene chloride (which is, in other settings, nasty stuff). In any case, at the risk of going dweeby here and introducing a bit more chemistry, I've gotta take issue with your water nomenclature. Maybe it's just a joke, in which case: never mind.

But, first of all, the official IUPAC nomenclature for this molecule is, uh, "water." Second, although dihyro oxide is an atomically correct description (sorta; I assume it's meant to be analogous to carbon dioxide, or something like that), you may remember from high school chemistry that water is made up of two ions -- H+ and OH-. That makes it technically a salt and makes its chemically accurate name hydrogen hydroxide (analogous to, for example, sodium chloride).

OK, that's enough chemistry for a Saturday morning. Over and out.

Sharon McEachern

Coffee -- regular or unleaded -- is a trade off. There is serious research that falls on both sides of the caffeine issue. For some people, like pregnant women,caffeine can cause serious repercussions -- more babies naturally abort and more babies develop leukemia. When you're past your baby-perculating years, you might want to discard decaf coffee because caffeine seems like it may help reduce your risks for Parkinsons and Alzheimers diseases.

I get weary of trying to decide which to chose and then feeling guilty regardless of my choice. If you'd like a break from all the seriousness about coffee, then lighten up with Ethic Soup's very funny article "25 Reasons You Know You've Had Too Much Caffeine." For example, if your eyes stay OPEN when you sneeze, you know you've had too much caffeine. Ditto when you start to chew on OTHER people's fingernails. You can find the article at:

http://www.ethicsoup.com/25-reasons-you-know-you’ve-had-too-much-coffee.html

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