Date: August 1997
Column/Title: Decaffeinated Coffees
Author: Ken Davids------------------------------------------------------------------------------------------------------------------------------------
Imagine it's a great recording, but your tweeter and woofer are on the fritz. Judging from this issue's selection of decaffeinated coffees, the decaffeination process tends to pass the taste of fine coffee through some rather attenuated speaker systems.
Top notes and bottom both tend to thin out, and even the middle ranges don't open up and resonate. Few shimmers at the top and even fewer deep echoes at the bottom.
On the other hand, there are some moderate successes here. At least one of the Kenyas definitely tastes like a Kenya, one of the Colombias like a Colombia, and so on. The caffeine-avoider may be getting Mozart through K-Mart speakers, but at least you know it is Mozart.
Furthermore, those who don't like the dry, sometimes brisk, sometimes wine-like sensation coffee people call acidity actually might prefer good decaffeinated versions of some coffees because (again, judging from this sampling) decaffeination seems to intensify sweetness while reducing the dry sensation of the acidity.
I often found it difficult to tell how much flavor was lost in the decaffeination process and how much in the roast. Decaffeinated coffees are notoriously difficult to roast. They start out brown in color rather than green, and respond in exaggerated and inconsistent ways to roasting heat.
In other words, they are very easy to overroast. And at least three of the coffees in this cupping struck me as overroasted. In other words, they probably were roasted darker than the roastmaster intended. They were blackish and oily to the eye, and tasted carbony and thin in the cup. At worst, they released their aromatics almost immediately in the nose, leaving little behind in the cup but the taste of the charred cellulose.
Conversely, I suspect that the coffees that succeed here are small, uncelebrated triumphs not only of decaffeination skill, but of careful and sensitive roasting working within a narrow margin for success.
I hope everyone understands that the diminished taste in these coffees has nothing directly to do with caffeine. Isolated, caffeine is a virtually tasteless white powder. The problem is what one does to the coffee to get the caffeine out.
Coffee is decaffeinated in the green, or unroasted, state. There are hundreds of patents for decaffeinating coffee, but currently two processes dominate the specialty coffee industry. In layman's terms, the "Swiss Water Process" (copyrighted name of course) involves soaking the beans in hot water until they've given up everything but the woody structure, running the waters through charcoal filters to remove the caffeine, then recombining the beans and the water. The beans soak up the good stuff from the water again, leaving the caffeine behind in the filters.
The "European process" (not a copyrighted name; so called because this process is accomplished in several plants in Europe) involves use of a solvent (usually methylene chloride), which selectively combines with the caffeine. The beans need to be steamed to open their pores and dissolve their waxy coating, but most of the stuff in the bean that eventually makes coffee taste like coffee remains inside the bean throughout the process, rather than being removed and then put back in again, as it is the Swiss Water Process.
For this and other reasons, the European process is generally considered less destructive to taste than the Swiss Water Process. It is also a bit cheaper, since the caffeine can be recovered and sold to soft drink and pharmaceutical manufacturers.
The problem with the European process, of course, is the troublesome idea that we could be eliminating caffeine while replacing it with leftover solvent. Decaffeinated coffee lovers can take heart from the following points, however. 1) Methylene chloride at this writing has not been linked to any known disease. 2) The U.S. government reports no significantly detectable residues of solvent remaining in green bean samples tested. 3) Methylene chloride volatilizes at about 104 F whereas coffee reaches internal temperatures of over 400 F during roasting. It seems likely that, even if the government tests are wrong, remaining solvent residues would be burned off and sent up the roaster chimney.
As far as flavor is concerned, the results of this cupping clearly support the idea that the European method takes less out of the coffee than the Swiss Water Process. There was one striking exception, however. Both the Roasterie and the Starbucks Kenyas were attractive coffees, but the Roasterie version, a Swiss Water, cupped truer to form than the Starbucks, which was decaffeinated by the European method. It may be that the Swiss Water Process takes less out of the acidity than the European process, but produces a delicate coffee that is easily ruined in the roaster.
When buying decaffeinated coffees I generally would pay more attention to roast than the decaffeination method. Avoid decaffeinated coffees that look extremely dark and oily, particularly if the store you are buying from doesn't usually present its coffees that way. When you add the ravages of a very dark roast to the rigors of any decaffeination process you are likely to have nothing left in the cup but carbon and water.
Most coffee drinkers already believed what Ken concluded in this month's cupping: despite on-going improvements in the quality of decaffeination technology, decaffeinated coffees simply don't taste quite as good as their caffeinated counterparts. Nevertheless, some ten to fifteen percent of coffee lovers elect to drink decaf to avoid the stimulating affects of caffeine. So, what is caffeine, the component of coffee that gives a jump-start to some and the "jitters" to others?
Chemically speaking, caffeine is one of a family of stimulants called methylxantine that occurs naturally in some plants, including the seeds of coffee trees. When occurring naturally, in food or beverages, caffeine does not need to be listed as an ingredient, so you won't find it on coffee packaging (for now.) However, it is also a food additive regulated by the Food and Drug Administration (FDA), which legally requires manufacturers to list caffeine when it is added. Some of the most common products that have caffeine added are cola soft drinks and over-the-counter medications such as pain relievers and stimulants.
The amount of caffeine in coffee depends on a number of factors including botanical variety, origin, and a couple controllable factors such as degree of roast, type of grind, and brewing method. For example, arabica beans, the primary variety used in specialty coffees, contain approximately half the caffeine of robusta beans, which are more common in grocery store canned coffees. Other things being equal, darker roasted coffees have lower levels of caffeine. Finer grinders and slower brewing methods tend to lead to greater extraction, which results in higher caffeine content as well.
Decaffeinated coffee must have a minimum of 97% of its caffeine removed. The amount of caffeine in a five-ounce serving of regular coffee ranges from 50 to 150 mg., meaning decaffeinated coffee contains two to five mg. of caffeine per five-ounce serving. As a point of comparison, a twelve-ounce serving of a caffeinated soft drink contains from 30 to 72 mg. Some popular soft drinks and their caffeine content are as follows:BrandCaffeine (mg./12 oz.)Jolt Cola72.0Mountain Dew54.0Coca-Cola45.6Dr. Pepper39.6Pepsi-Cola38.4
There are a variety of methods for removing caffeine from coffee but only a couple are widely used commercially. The two broad categories are the direct solvent extraction method and the indirect water extraction method. Each process uses a solution of water saturated with coffee oils and flavor elements, but in the former a solvent comes in direct contact with the coffee beans, while, in the latter, the decaffeinating agent does not physically touch the beans.
In the direct solvent process, or European process, unroasted green beans are steamed in a rotating drum for about a half hour to open the pores of the beans. The beans are then repeatedly rinsed directly with a solvent, typically methylene chloride or ethyl acetate, for up to 12 hours, during which time the caffeine is extracted from the beans. Next, the beans are removed from the solvent (or vice versa) and steamed for another eight to twelve hours to evaporate the majority of the remaining solvent. Finally, the beans are dried to reduce the moisture levels appropriate for roasting. Trace amounts of solvent remain in the coffee but burn off in the roasting process.
Another direct processing method similar to the one above often described as the "natural process," uses a decaffeination agent called ethyl acetate, a compound found in fruits such as apples, peaches, and pears. In the indirect extraction process, often loosely referred to as the "water process," green beans are soaked for several hours in a near-boiling water solution saturated with coffee flavor components. Caffeine, which is water soluble at temperatures above 175 F, is removed from the beans, along with other critical coffee oils and flavor elements. The solution is drained and methylene chloride is added to absorb the caffeine. The solution, now void of solvent and caffeine, is returned to the coffee beans so that most of the key flavor components can be reabsorbed. Though solvents are used, they never come indirect contact with the coffee beans.
Another popular indirect process is called the Swiss Water Process? because it was originally developed by a Swiss company almost sixty years ago. This method is similar to other indirect methods, but activated charcoal, not solvents, remove caffeine from the soaking solution. This process, along with the ethyl acetate direct process, are preferred by environment-conscious consumers because of the potentially damaging affects of methyl chloride on the ozone layer.
On a final note, if you are looking for ways to reduce your caffeine intake without giving up coffee or sacrificing taste, there are a couple creative alternatives to decaffeinated coffee. Besides simply drinking less regular coffee, experiment with blending regular coffees naturally low in caffeine with a decaffeinated coffee to create your own favorite low-caffeine coffee. Try mixing one part of a distinctive, full-bodied regular arabica coffee such as Kenya, Yemen Mocha, Sumatra, or Guatemala with two parts of a mild decaffeinated coffee such as Costa Rican or Colombian. The resulting blend will have 80 to 85% less caffeine per cup than popular grocery store coffees and taste like a true specialty coffee.------------------------------------------------------------------------------------------------------------------------------------