Decaffeination is the act of removing caffeine from coffee beans, cocoa, tea leaves and other caffeine-containing materials. (While caffeine-free soft drinks are occasionally referred to as "decaffeinated", some are better termed "uncaffeinated": prepared without adding caffeine during production.) Despite removal of most caffeine, many decaffeinated drinks still have around 1–2% of the original caffeine remaining in them, and research has found that certain decaffeinated coffee drinks can contain around 20% of the original caffeine.
In the case of coffee, various methods can be used. The process is usually performed on unroasted (green) beans, and starts with steaming of the beans. They are then rinsed with a solvent that extracts the caffeine while leaving the other essential chemicals in the coffee beans. The process is repeated anywhere from 8 to 12 times until it meets either the international standard of having removed 97% of the caffeine in the beans or the EU standard of having the beans 99.9% caffeine-free by mass. Coffee contains over 400 chemicals important to the taste and aroma of the final drink: It is, therefore, challenging to remove only caffeine while leaving the other chemicals at their original concentrations.
Coffea arabica normally contains about half the caffeine of Coffea robusta. A Coffea arabica bean containing little caffeine was discovered in Ethiopia in 2004.
Read more about Decaffeination: Roselius Process, Swiss Water Process, Direct Method, Indirect Method, CO2 Process, Triglyceride Process, Decaffeinated Tea, Caffeine Content of Decaffeinated Coffee, Health Effects of Decaffeinated Coffee, Decaffito