Decaffeinated coffee has had most of its caffeine stripped out by extraction with water, organic solvents or supercritical carbon dioxide. Green beans are treated before roasting, drawing out the stimulant while leaving flavour compounds largely intact. Good decaf tastes close to the original, though some aroma inevitably escapes. Regulations cap residual caffeine and solvent traces, and labelling must be honest about the process so consumers know what they are drinking. Swiss Water and carbon dioxide methods appeal to buyers seeking chemical-free decaffeination.