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Tea
From Wikipedia, the free encyclopedia
T
ea is the second most popular beverage in the world (the most popular is water). It is 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. There are four typesof true tea: black tea, oolong tea, green tea, and white tea. Tea is a natural source of caffeine, theophylline, and antioxidants, although it has almost no fat, carbohydrates, or protein. It has a cooling, slightly bitter and astringent taste. Iced Tea has been popular in North America since the 1904 St. Louis World's Fair.


The term herbal tea usually refers to infusions of fruit or herbssuch as rosehip tea, chamomile tea and Jiaogulan that contain no tea leaves. Alternative terms for herbal tea that avoid the misleading word "tea" are tisane and herbal infusion. This article is concerned exclusively with preparations and uses of the tea plant Camellia sinensis.
Cultivation
Main article: Camellia sinensis
In the wild, the tea plant Camellia sinensis may grow from 5 to 15 m, andsometimes even to 30 m.( Arcimovicova p. 43. See also a photo of an exceptionally old and big tea tree called "King tea plant" (taken by SMČ tea expedition, 1997)) The natural distribution consists of the foothills of the Himalayas, from northeast India to southwest China( Mansfeld's Database Taxonomy Module: Camellia sinensis. Retrieved on 2006-07-22.), areas with subtropical monsoon climateswith wet and hot summers and relatively cold and dry winters.( Arcimovicova p. 46) Today, it is cultivated in many tropical and subtropical regions. In tropical regions, the best conditions are at higher altitudes. Important tea producing regions are mainland China, Taiwan, India, Kenya, Sri Lanka, Japan, Indonesia, Nepal and Bangladesh. (In the tea trade, Sri Lanka and Taiwan are still referred toby their former names of Ceylon and Formosa, respectively.) Recently the Tregothnan Estate in Cornwall, England has started growing tea.( Tregothnan Tea. Retrieved on 2006-07-22.) Tea has also been cultivated in the United States since 1744. (See Tea production in United States).


Cultivated tea shrubs are usually trimmed to below 2 m (six feet) to stimulate the growth of leaves and to easeplucking. Many insects, including green leafhoppers, mites, caterpillars, and termites, are natural enemies of tea plants.
Several varieties of Camellia sinensis are used for tea making, among them the Assam, China, Hong Kong and Cambodian varieties that differ in flavour, preferred climate and soil, and growing habit (some are shrubs, some trees).
About 3.2 million tonnes of tea were producedworldwide in 2004.( FAO figures. Retrieved on 2006-07-22.) India, China, Sri Lanka and Kenya (in descending order) are the most prolific producers of tea leaves. ( Agritrade tea executive brief. Retrieved on 2006-07-22.)
Processing and classification
The types of tea are distinguished by their processing. Leaves of Camellia sinensis, if not dried quickly after picking, soon begin to wilt andoxidize. This process resembles the malting of barley, in that starch is converted into sugars; the leaves turn progressively darker, as chlorophyll breaks down and tannins are released. The next step in processing is to stop the oxidation process at a predetermined stage by removing the water from the leaves via heating.
The term fermentation was used (probably by wine fanciers) to describe thisprocess, and has stuck, even though no true fermentation happens (i.e. the process is not driven by microbes and produces no ethanol). Without careful moisture and temperature control, however, fungi will grow on tea. The fungi cause real fermentation which will contaminate the tea with toxic and carcinogenic substances, so that the tea must be discarded.
Tea is traditionally classified based on the...