Decaffeinated Coffees
Technology is always trying to give us back the garden without the snake. So you like coffee and not caffeine? Well, then, we will take out the caffeine and leave you your pleasure, intact.
Decaffeinated coffee is indeed without venom. It contains, at most, one fortieth of the amount of caffeine in untreated beans. Nor should the removal of caffeine alter the taste of coffee. Isolated, caffeine is a crystalline substance lacking aroma and possessing only the slightest bitter taste. Its flavor is lost in the heady perfumes of fresh coffee. So if you hear people say, "Coffee doesn't taste like coffee without the caffeine," they are wrong. The only real problem is how to take out the caffeine without ruining the rest of what does influence coffee flavor. But technology has triumphed, more or less. The best decaffeinated coffee, freshly roasted and ground and carefully brewed, can taste so nearly the equal of a similar untreated coffee that only a tasting involving direct comparison reveals the difference.
Unfortunately, fine decaffeinated coffees are the exception rather than the norm. Decaffeinated beans are notoriously difficult to roast, so even the best decaffeinated beans may produce a thin-bodied, half-burned cup once they are roasted. Still, for the coffee devotee even listless decaffeinated coffee is better than mint tea, and you can always compromise and spruce up a caffeine-free coffee by adding a little full-bodied caffeinated coffee before grinding it, or by creating your own low-caffeine blend.
Coffee is decaffeinated in its green state, before the delicate oils are developed through roasting. Hundreds of patents exist for decaffeination processes, but only a few are actually used. They divide roughly into those that use a solvent to dissolve the caffeine, those that use water and charcoal filters, and those that use a special form of carbon dioxide.
Solvent Method of Making Defaffinated Coffee:
The direct solvent method is the most common and oldest process of decaffeination. On bags of coffee it is not typically identified a whole, or is called by various euphemisms like the European or traditional process. The beans are initially cooked with water to open their pores, and then soaked in an organic solvent which links selectively with caffeine. The beans are then cooked with water vapor again to remove the residues solvent, dried, and roasted like any other raw coffee.
Swiss Water Method:
In the 1980s the Swiss firm Coffex S.A. developed a commercially viable decaffeination process using water only -- no solvents whatsoever. As in the indirect solvent or solvent/water process described earlier, the various chemical constituents of the green coffee, including the caffeine, are first removed by soaking the beans in very hot water.
This process is more costly than the solvent process because the separated caffeine cannot be recovered from the charcoal and sold separately. Many coffee professionals contend that the Swiss Water Process blurs flavor more than the competing solvent processes. However, the Canadian plant that currently produces all of the Swiss Water Decaffeinated coffees sold in North America continues to make determined efforts to refine and improve the process.
Carbon Dioxide Method:
Decaffeination processes using carbon dioxide (CO2) differ in their details. All take advantage of the fact that carbon dioxide, when compressed, behaves partly like a gas and partly like a liquid, and has the property of combining selectively with caffeine. In the most widely used CO2 process the steamed beans are bathed in the compressed carbon dioxide and the caffeine is removed from the carbon dioxide through charcoal filtering, just as it is in the water-only process. However, the flavor components remain in the bean throughout the process, rather than being soaked out and then put back in again, as they are in both the Swiss Water and the indirect solvent processes.
Coffees decaffeinated by the CO2 method have been slow to come onto the specialty market, and reviews have been mixed.
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