Decaffeination is the process of taking caffeine out of coffee, for those times when you want that coffee flavor, but don’t want the jitters that come with it. There are a lot of processes that have been used, but most conventional decaffeination processes involve the use of a chemical solvent. These can cause health problems, due to residues left in the bean.

The Roselius process, an old fashioned method using benzene, is no longer in use, but chemicals such as methylene chloride and ethyl acetate, triglycerides, and other unpleasant substances are still being used for decaffeinating conventional coffee. These are the subject of health concerns, and are not permitted for removing the caffeine from organic coffee. For decaffeinating organic coffee, one of two methods is generally used.

The Swiss Water Process was developed in the 1930s in Switzerland, but the only facility currently processing coffee this way is actually based near Vancouver, in Canada. The Swiss Water Process involves soaking beans in hot water, releasing caffeine. The beans are then discarded (after all coffee solids and caffeine have been released into the water) and the liquid is passed through a carbon filter. The caffeine is trapped, but coffee solids are passed through.

The resulting solution is called flavor charged water by the company, and is filtered again. Then, new coffee beans are added. This water can’t accept any more coffee solids, being completely saturated with them, but it can accept caffeine, so only the caffeine is removed from these beans. The process is repeated until the beans are almost entirely caffeine free. They retain most of their smell and flavor, and have no solvent residue, since no solvents are used.

Another process uses carbon dioxide. Called supercritical fluid extraction, it involves steaming the beans, then soaking them in supercritical carbon dioxide at high pressure. After the beans are soaked, the pressure is reduced and the CO2 evaporates, taking the caffeine with it. The pressurized CO2 may also be run through a charcoal or water filter to remove the caffeine. This liquid is somewhat more effective than water, requiring fewer filtrations, and also avoids the use of solvents, resulting in a safe, nearly caffeine free bean.