Coffee from which caffeine has been removed, either chemically or using water filtration. A variety of methods for decaffeination exist, but all operate on the same basic principle: coffee is soaked in a liquid (water or pressurized carbon dioxide) bath and the caffeine is extracted from the liquid. See SWP, CO2 process, Ethyl Acetate. Decaffeinated beans have a much darker appearance and give off little chaff when roasting. Decafs will roast differently than regular coffees because of their altered state; in most roasting methods, they will roast faster than regular beans.