One of two methods for
decaffeinating coffee. (The other is the
European Process.) This process uses no chemicals, but rather hot water and steam to remove the caffeine from the coffee.
Coffee beans are circulated in water saturated with coffee flavor, known as "
flavor-charged" water. This water draws out the caffeine while insuring that the full coffee flavor remains in the bean.
Then the water solution is put through activated charcoal filters to remove the caffeine. Once the caffeine is removed, the same beans are then put back into the decaffeinated solution to reabsorb everything except the
caffeine.
The disadvantage is that the water processing removes more than just the caffeine. Some of the oils from the coffee bean are removed as well, making it less flavorful.