The process of removing most of the caffeine from coffee beans or tea leaves while keeping as much flavor as possible. Common industrial methods include the Swiss Water process, which uses water and activated carbon; supercritical carbon dioxide extraction; and solvent methods employing ethyl acetate or methylene chloride, followed by steaming to remove residues. Regulations typically require at least 97 percent of caffeine to be removed for a product sold as decaffeinated, leaving a cup with only a few milligrams compared with roughly 75 to 150 milligrams in regular coffee. Each method affects aroma and taste differently, and green-bean decaffeination generally preserves flavor better than treating roasted beans. Tea is harder to decaffeinate evenly, which is why decaf teas often taste noticeably thinner than their regular versions.