The Swiss Water Process (SWP) is a non-solvent method or decaffeinating unroasted coffee beans. It was introduced by Coffex in 1979 and was, at that time, the only commercial decaffeination method that did not use solvents. The Swiss Water Process has quickly become one of the most popular methods of decaffeinating specialty coffee. This process was developed in Switzerland, hence the name, Swiss Water.
In this process, the coffee beans are soaked in caffeine-free green coffee extract, allowing the caffeine to be extracted from the bean and into the solution while the flavor components are retained in the beans. The now caffeine-saturated green coffee extract is then processed through activated charcoal to remove the caffeine, thus becoming caffeine-free again and ready to extract caffeine from a new batch of coffee. The coffee beans are then dried to their originating moisture level and re-bagged. The Swiss Water Process results in coffee that is 99.9% caffeine free.
In other methods of decaffeination, the caffeine is recovered from the mixture and sold separately from the coffee. Typically, caffeine is captured through the introduction of a volatile solvent (such as methylene chloride or ethyl acetate), which allows the caffeine to attach to the solvent and then be recovered through dehydration. However, in the Swiss Water Process, no chemical solvents are used. The cost of this process is usually slightly higher than solvent-based processes.
