method. In this method, instead of treating the beans directly, they are first soaked in hot water for several hours, then removed. The remaining water is treated with solvents (e.g. dichloromethane or ethyl acetate) to extract the caffeine from the water. As in other methods, the caffeine can then be separated from the organic solvent by simple evaporation. The same water is recycled through this two-step process with new batches of beans. An equilibrium is reached after several cycles, wherein the water and the beans have a similar composition except for the caffeine. After this point, the caffeine is the only material removed from the beans, so no coffee strength or other flavorings are lost. Because water is used in the initial phase of this process, indirect method decaffeination is sometimes referred to as "water-processed". This method was first mentioned in 1941, and people have made great efforts to make the process more "natural" and a true water-based process by finding ways to process the caffeine out of the water in ways that circumvents the use of organic solvents. Swiss Water process An alternative method for removal of caffeine from coffee is the Swiss Water process. This process uses no organic solvents, and instead only water is used to decaffeinate beans, a technique first developed in Switzerland in 1933, and commercialized by Coffex S.A. in 1980. The Swiss Water process was then introduced by The Swiss Water Decaffeinated Coffee Company of Burnaby, British Columbia, Canada, in 1988. The process uses green coffee extract (GCE) for the caffeine extraction mechanism. Green coffee extract is a solution containing the water-soluble components of green coffee except for the caffeine, obtained by soaking green coffee beans in hot water, then filtering through an activated charcoal filter to remove the caffeine molecules. Fresh beans containing both caffeine and the other components are added to the GCE solution, where the gradient pressure difference between the GCE (which is caffeine-lean) and the green coffee (which is caffeine-rich) causes the caffeine molecules to migrate from the green coffee into the GCE. Because GCE is saturated with the other water-soluble components of green coffee, only the caffeine molecule migrates to the GCE; the other water-soluble coffee elements are retained in the green coffee. The newly caffeine-rich GCE solution is then passed through the activated carbon filters to remove the caffeine again, and the process is repeated. The continuous batch