Peet's new Decaffeinaton Ristretto Espresso Capsules are decaffeinated using the carbon dioxide method. Carbon dioxide makes an ideal solvent for caffeine, making it possible to decaffeinate coffee while retaining the valuable flavors and aroma of the coffee. In the carbon dioxide decaffeination process, green coffee beans are soaked in highly compressed CO2, which extracts the caffeine. The caffeine is then removed from the CO2 using activated carbon filters, which are then reused to extract caffeine from the coffee again.