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Two Types of Decaf Processes

There are two types of decaffeination processes. The first is called the Swiss Water Process method. Decaf coffee made with this method can be found at most gourmet coffee shops, organic food grocery stores. The other decaffeination processes use some sort of a chemical solvent. In this article, I'll explain the essential aspects of the chemical removal process then I'll discuss a specific variation of the chemical process termed the Super Critical Carbon Dioxide method.

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The Supercritical Carbon Dioxide Method

The Supercritical Carbon Dioxide method is a chemical method that is somewhat dissimilar to the other chemical methods; therefore it deserves special attention. This method uses carbon dioxide at 250 - 300 times normal atmospheric pressure. Carbon dioxide in this form looks like a liquid in terms of its density, but it has the viscosity of a gas. It is a very effective solvent at the high pressures. When the coffee beans are exposed to the solvent, the caffeine migrates to the solvent. When the removal of caffeine is complete, the now caffeine-rich carbon dioxide is passed through either an activated charcoal bed or a bath of water to absorb the caffeine for re-use. Like other chemical methods, the Supercritical Carbon Dioxide method removes 96 - 98% of the caffeine. Carbon dioxide is inexpensive to obtain and non-toxic.