Coffee processing of decaffeination

Caffeine is a physiologically active component in coffee, was been studied intensively. The process of decaffeinating coffee began at the turn of the last century, in Germany.

Decaffeinated coffee means in the EU countries a maximum caffeine concentration of 0.1% related to the dry mass; in the US, it means less than 3% of the amount initially present in the beans.

Today there are only three primary decaffeination methods used by the coffee industry.

*The Swiss water process or water only method
Swiss water decaffeination almost always uses high quality arabica beans. This process does not use chemicals.

In this process method the green coffee beans are soaked in water for several hours, which removes about 97 percent of the caffeine as well as a few of the flavor components.

*The water decaffeinated method 
The method was first mentioned in 1941 by Berry and Walters. It uses green coffee extract with equilibrium quantities of non-caffeine soluble solids and removal of caffeine from the extract with dichloromethane on liquid-liquid extraction.

In water decaffeination process, sometimes chemicals rather than charcoals filters, are used to extract the caffeine. In this process, no solvent touches the beans. After the beans are steamed, they are soaked in water in big vats, which removes the caffeine along with all the soluble solids in the beans.

*The solvent method
Certain solvents, such as methylene chloride and common ethyl acetate, are the most widely used chemical compounds to decaffeinate coffee.

A raw green beam is softened with steam and water allowing bean to double in size. The beans are vibrated for about an hour in the solvent, which loosens the caffeine and combines it with the chlorine.

The commercial decaffeination process is at present carried out on the green coffee beans before roasting.
Coffee processing of decaffeination