Tea is one of the most widely-consumed beverages in the world. It has a cooling, slightly bitter, astringent flavor. It has almost no carbohydrates, fat, or protein. Tea is a natural source of the amino acid theanine, methylxanthines such as caffeine and theobromine, and polyphenolic antioxidant catechins.
Camellia sinensis is an evergreen plant and grows in tropical to sub-tropical climates. In addition to tropical climates (at least 50 inches of rainfall a year), it also prefers acidic soils. Many high quality tea plants grow at elevations up to 1500 meters (5,000 ft), as the plants grow more slowly and acquire a better flavor. Only the top 1-2 inches of the mature plant are picked. These buds and leaves are called flushes, and a plant will grow a new flush every seven to ten days during the growing season.
Tea plants will grow into a tree if left undisturbed, but cultivated plants are pruned to waist height for ease of plucking.
Two principal varieties are used, the small-leaved China plant (C. sinensis sinensis) and the large-leaved Assam plant (C. sinensis assamica).
Tea is traditionally classified based on producing technique:
- Green tea: Un-wilted and unoxidized
- Yellow tea: Un-wilted and unoxidized but allowed to yellow
- White tea: Wilted and unoxidized
- Oolong: Wilted, bruised, and partially oxidized
- Black tea/Red tea: Wilted, crushed, and fully oxidized
- Post-fermented tea: Green Tea that has been allowed to ferment/compost
Green Pu-erh tuo cha, a type of compressed raw pu-erh