This method utilizes water as the decaffeinating agent. The green beans are immersed in water (without chemical additives) for several hours until at least 97-99 of the caffeine is removed. The resulting solution, which contains caffeine as well as other essential coffee elements, is passed through activated charcoal or carbon filters to remove the caffeine. The filtered extracts from the coffee are then added back to the coffee beans. This process is sometimes called "Swiss Water Process" because it was originally developed by a Swiss company.