Decaffeination

The amount of caffeine that is required to be removed in order to be labelled as Decaffeinated is not consistent worldwide. In Europe the maximum amount of caffeine allowed to remain is 0.1% by weight in either green or roasted beans.

Traditionally caffeine was removed from the raw beans by the addition of solvents in water. This involved putting dichloromethane (known as Methylene Chloride) in water and then adding the green beans. Steam was then added to the mix which made the beans swell up  by up to 40% in weight. This added water content was found to liberate the caffeine from within the bean which was then dried to return to its original water content.  Whilst this was a successful method of caffeine removal it also did a very good job of removing the main flavour characteristics of the coffee and replacing them with a somewhat unpleasant chemically tasting residue.

In 1979 the first water only decaffeination process was commercially begun although its origins go back to 1933 at least.

In order to be able to decaffeinate coffee by this method you first need to create something called Green Coffee Extract. This is an extract that has been made by processing a batch of raw coffee to remove the caffeine whilst also allowing the soluble coffee solids  (the flavour) to be removed as well. This batch of raw coffee is then discarded and the remaining caffeine in the extract is removed by passing  the liquid through charcoal filters. You are then left with the extract that is “full of coffee flavour”. The next batch of coffee to be processed is then rehydrated, to the correct moisture content to allow the removal of the caffeine, the Green Coffee Extract is added to the mix and the process repeated. The caffeine from this batch of coffee is removed but the flavour remains within the bean as there is no room in the extract for it to be released. The green beans are then removed from the solution and dried to remove the excess moisture. The result is 99.9% caffeine free coffee that retains all of its coffee flavour.

Other methods  of decaffeination without removing flavour have now been discovered such as Co2 and Sparkling Water.

A byproduct of the Co2 decaffeination process is called crude caffeine which is sold to be added to many non-caffeine containing food products such as energy drinks.