Tea is a beverage made by steeping processed leaves, buds, or twigs of the tea bush (Camellia sinensis) in hot water for a few minutes. The processing can include oxidation (fermentation), heating, drying, and the addition of other herbs, flowers, spices, and fruits.
Tea is a natural source of methylxanthines such as caffeine , catechins, and theanine. It has almost no carbohydrates, fat, or protein. It has a cooling, slightly bitter and astringent taste.
There are four basic types of true tea:
The tea leaves are allowed to completely oxidize. Black tea is the most common form of tea in southern Asia (Sri Lanka, India, Pakistan, Bangladesh, etc.) and in the last century many African countries including Kenya, Burundi, Rwanda, Malawi and Zimbabwe. The literal translation of the Chinese word is redtea, which is used by some tea lovers. The Chinese call it red tea because the actual tea liquid isred. Westerners call it black tea because the tea leaves used to brew it are usually black. However, red tea may also refer to rooibos, an increasingly popular South African tisane. The oxidation process will take between two weeks and one month. Black tea is further classified as either orthodox or as CTC (Crush, Tear, Curl, a production method developed about 1932). Unblended black teas are also identified by the estate they come from, their year and the flush (first, second or autumn). Orthodox and CTC teas are further graded according to thepost-production leaf quality by the Orange Pekoe system.
Oxidation is stopped somewhere between the standards for green tea and black tea. The oxidation process takes two to three days. In Chinese, semi-oxidizedteas are collectively grouped as blue tea (literally: blue-green tea), while the term "oolong" is used specifically as names for certain semi-oxidized teas.
The oxidation process is stopped after a minimal amount of oxidation by application of heat, either with steam, a traditional Japanese method, or by dry cooking in hot pans, the traditional Chinese method. Tea leaves may be left to dry as separate leaves or they may be rolled into small pellets to make gun-powder tea. This process is time consuming and is typically done with pekoes of higher quality. The tea is processed within one to two days of harvesting.
Young leaves (new growth buds) that have undergone no oxidation; the buds may be shielded from sunlight to prevent formation of chlorophyll. White tea is produced in lesser quantities than most other styles, and can be correspondingly more expensive than tea from the same plant processed by other methods. It is less well known in countries outside of China, though this is changing with increased western interest in organic or premium teas