In the first episode of the new Mental Floss video series “The Big Question”, host Craig Benzine answers the reader question, “How do they make decaf coffee when the caffeine is in the bean?” There are several methods for removing caffeine, but none of them work at 100-percent efficiency.
The decaffeination process doesn’t remove 100-percent of caffeine from coffee beans; usually 94 to 98-percent is removed.