There are two sources of decaffeinated tea in the world, both processed by firms in Europe. Decaffeinated tea is found in all leaf grades and a great variety of flavors. There are three processes used to decaffeinate tea: methylene chloride, ethyl acetate and CO2, the latter two are the only two permitted in the United States. The use of methylene chloride on tea uses the same processing methods as ethyl acetate (see below) but is not allowed for import to the United States. CO2 is a high pressure, super critical process. Unlike the other two processes mentioned, this process is considered natural and is more gentle to the tea leaves. The ethyl acetate process of decaffeination also removes 90% of the teas original acids while the CO2 process removes only 10%.
Ethyl Acetate Process
Ethyl Acetate is used as an organic solvent that is passed over the leaves to extract the caffeine content. The finished product has less then a 1ppm ethyl-acetate residue, and is 99.9 percent decaffeinated. This process also removes 90 percent of the acid in black tea.
CO2 is a high pressure, super critical process. Unlike the other process mentioned, this process is considered natural and is more gentle to the tea leaves Supercritical Carbon Dioxide is the most widely used solvent for decaffeination of food products. The gas is odorless, tasteless and inert. CO2 processing leaves no toxic residues. In addition, extraction of the caffeine takes place at room temperature, which protects product quality by preventing the breakdown of temperature-sensitive components. As a result, the CO2 process removes 99.9 percent of the caffeine and only 10 percent of the acid. After extraction occurs, the supercritical fluid turns back into a gas, so no solvent residue remains. The decaffeination processes run under normal, official food control and fully comply with the Swiss and European food laws.