Fermentation Process Of Black Tea, Green Tea And Oolong Tea - The Ins And Outs Of Tea Oxidation

Black tea, green tea and oolong tea are produced from the same Camellia Sinensis tea plant. The plant is grown in tropical and subtropical regions such as South and Southeast Asia. The differences in the final type of tea strictly develop from the process by which the tea is fermented. Fermentation in teas is somewhat different than the typical fermentation process that is substances such as wine undergo. The tea fermentation process allows the leaves to transform through enzymatic oxidation while drying. The process of fermentation is sustained by steaming or pan frying before they are completely dried, resulting in a non fermented state, a semi fermented state or a fully fermented state.

Green tea is included in the grouping of non-fermented or very light fermented teas. Much of the original tea leaf flavor remains in lightly fermented teas. The fermentation process is halted in green teas most often by pan frying. Only a few of non-fermented teas will stop fermentation by using the steaming process. Occasionally, lightly fermented or semi fermented teas are sometimes enhanced with other herbs such as Jasmine. These additions will provide additional aroma and augment the flavor of the lightly fermented tea. Additional teas that fall into this category are Pi Lo Chun, Sencha, yellow teas and white teas.

Semi-fermented teas go through 10 - 80 % fermentation. There is a largely broad category of semi-fermented teas. A partial fermentation process produces teas that are brown or yellow in color and will also produce a fragrant smell. Three categories of semi-fermented teas are assessed based on the level of fermentation process the tea has undergone. Light semi-fermented teas are 10 - 20 % fermented. This category includes Jasmine teas. Semi-fermented teas which are in the medium range have processed 20 - 50 % through fermentation. Oolong tea as well as Tung-Ting and Ti-Kuan teas falls in this group. Heavy semi-fermented teas are fermented from 50 - 80 % of the process. Champagne Oolong tea is considered to be a heavy tea.

Finally, fully-fermented teas are produced through 100% fermentation. This type of tea is usually dark red and has a sweet, sugary smell. Black teas are considered to be fully fermented. During the fermentation process, the possibility of developing fungi is high. Careful temperature and moisture techniques must be used to ensure the tea is not contaminated with toxic or even carcinogenic elements during the fermentation process. By using proven and controlled oxidation techniques, all teas will be suitable and enjoyable for individual consumption.