1. Unfermented tea: Green tea is the most representative one among these kinds of unfermented tea. In view of production processes, because tea leaves are immediately steamed, blanched and heated in large pots, the enzyme will be destroyed. Therefore, the ingredients, such as catechins and tannins are not metamorphic and oxidized, belonging to strong antioxidants. They can strengthen the antioxidant enzyme activity in human cells with the colors of tea broth becoming slightly yellow and green.
2. Semi-fermented tea: Oolong tea, jasmine tea and Pouchong are the most representative ones. When semi-fermented tea is produced, it will be experienced with sun withering previously to remove the moisture in tea leaves with a semi-fermented state reachable. After the completion of blanching, the tannic acid in tea leaves is oxidized by enzymes and tea broth becomes brownish red.
3. Fully Fermented Tea: Black tea is the most representative one. After tea picking, it is withered. The cell walls of tea leaves are destroyed by hand to make enzymes released. After fermentation, tea leaves are roasted. During the period, enzymes will oxidize most catechin tannin into condensed tannin with the color of tea broth becoming dark red.