People sometimes wonder how coffee beans are decaffeinated - is there a naturally caffeine-less variety of bean grown, or is decaffeinated coffee somehow chemically stripped of its caffeine? In some cases, the answer is "neither." There have been a variety of decaffeination techniques used over the years, some of which made use of natural or chemical solvents which left very few or no residues in the beans themselves. Since some of these chemical solvents were later determined to be carcinogenic, there are only a handful of decaffeination methods in use today.

The most obvious option is water decaffeination - however, water alone cannot be used because it absorbs too many of the substances in coffee which provide its rich flavor and aroma. Because of this, in most cases a chemical solvent such as ethyl acetate (found in small quantities in fruit) or methylene chloride is used to strip the caffeine out of the water, and the water is then brought back to the beans and dried, returning the flavor-enhancing compounds to the 96-98% decaffeinated beans. These processes are guaranteed to leave no more than the legal limit of solvent (typically under 10 parts per million) and are certified by the US Food and Drug Administration to be safe for human consumption.

Some health-conscious coffee drinkers cringe at the idea of any chemical solvent being used in their coffee, whether it is naturally derived or not. For these folks, there is the Swiss water method of decaffeination, in which the beans are soaked in hot water, and then the water is run through filters (such as activated carbon or charcoal) to strip away the caffeine. The water is then returned to the beans before the beans are dried, returning some but not all of the flavor and aroma to the beans. This method is considered more environmentally friendly, and many decaf drinkers refuse to purchase beans processed any other way. However, given the flavor reduction, it isn't ideal for many coffee lovers.

The last, and some would argue the best, of these three choices involves the use of compressed liquid carbon dioxide instead of water as a solvent - the liquid CO2 is pumped into the beans after a light water soak, and then it is drained off of the beans. Because of its molecular characteristics, CO2 is able to absorb the caffeine while leaving behind the flavor components in the coffee. This method is generally considered the most environmentally friendly, and provides the most flavorful decaffeinated coffee with absolutely zero residual chemicals remaining in the final product.

So whether you are interested in lowering your caffeine intake or you just want a late-night cup of coffee without the caffeine rush, now you can make a decision as to which type of bean processing you'd prefer as an informed consumer and coffee connoisseur!