Health Benefits Of Tea

Camellia sinensis is an evergreen plant that grows mainly in tropical and sub-tropical climates. Nevertheless, some varieties can also tolerate marine climates and are cultivated as far north as Cornwall on the UK mainland and Seattle in the United States.

Historically, tea has been served as a part of various ceremonies and has been used to stay alert during long meditations. A legend in India describes the story of Prince Siddhartha Gautama, the founder of Buddhism, who tore off his eyelids in frustration at his inability to stay awake during meditation while journeying through China.

A tea plant is said to have sprouted from the spot where his eyelids fell, providing him with the ability to stay awake, meditate, and reach enlightenment. Turkish traders reportedly introduced tea to Western cultures in the 6th century. By the 18th Century, tea was commonly consumed in England, where it became customary to drink tea at 5 p.m.

Tea plants require at least 50 inches of rainfall a year and prefer acidic soils. Many high-quality tea plants are cultivated at elevations of up to 1500 meters (5,000 ft). At these heights, the plants grow more slowly and acquire a better flavour. The four types of tea most commonly found on the market are black tea, oolong tea, green tea and white tea, all of which can be made from the same bushes, processed differently, and in the case of fine white tea grown differently. Pu-erh tea, a double-fermented black tea, is also often classified as amongst the most popular types of tea.

There is also herbal tea. However, contrary to what most people believe, herbal tea is a herbal infusion made from anything other than the leaves of the camellia sinensis plant. In effect, the term "herbal tea" usually refers to an infusion or tisane of leaves, flowers, fruit, herbs or other plant material that contains no Camellia sinensis.

There is also red tea. The term "red tea" either refers to an infusion made from the South African rooibos plant, also containing no Camellia sinensis, or, in Chinese, Korean, Japanese and other East Asian languages, refers to black tea. During harvest, only the top 1-2 inches of the mature plant are picked. These buds and leaves are called flushes. A plant will grow a new flush every seven to ten days during the growing season.

A tea plant will grow into a tree if left undisturbed, but cultivated plants are pruned to waist height for ease of plucking. A tea's type is determined by the processing which it undergoes. Leaves of Camellia sinensis soon begin to wilt and oxidize if not dried quickly after picking. The leaves turn progressively darker as their chlorophyll breaks down and tannins are released. This process, enzymatic oxidation, is called fermentation in the tea industry, although it is not a true fermentation: it is not caused by micro-organisms, and is not an anaerobic process.

The next step in processing is to stop the oxidation process at a predetermined stage by heating, which deactivates the enzymes responsible. With black tea this is done simultaneously with drying. Without careful moisture and temperature control during manufacture and packaging, the tea will grow fungi. The fungus causes real fermentation that will contaminate the tea with toxic and sometimes carcinogenic substances, as well as off-flavors, rendering the tea unfit for consumption.

Tea leaf processing methods (Simplified)Tea is traditionally classified based on the techniques with which it is produced and processed. White tea: Unwilted and unoxidized Yellow tea: Unwilted and unoxidized but allowed to yellow Green tea: Wilted and unoxidized Oolong: Wilted, bruised, and partially oxidized Black tea: Wilted, sometimes crushed, and fully oxidized Post-fermented tea: Green Tea that has been allowed to ferment/compost Black tea is a variety of tea that is more oxidized than the oolong, green, and white tea varieties. Black tea is generally stronger in flavor and contains more caffeine than the less oxidized teas. Two principal varieties of the species are used, the small-leaved Chinese variety plant (C. sinensis sinensis), also used for green and white teas, and the large-leaved Assamese plant (C. sinensis assamica), which was traditionally only used for black tea, although in recent years some green has been produced.

The tea plant is native to Southeast Asia and can grow up to a height of 40 feet, but is usually maintained at a height of two to three feet by regular pruning. The first spring leaf buds, called the first flush , are considered the highest-quality leaves. When the first flush leaf bud is picked, another one grows, which is called the second flush , and this continues until an autumn flush . The older leaves picked farther down the stems are considered to be of poorer quality.

In Chinese and Chinese influenced languages, black tea is known as "crimson tea", perhaps a more accurate description of the colour of the liquid. The name black tea, however, could alternatively refer to the colour of the oxidized leaves. In Chinese, "black tea" is a commonly used classification for post-fermented teas, such as Pu-erh tea. However, in the Western world, "red tea" more commonly refers to rooibos, a South African tisane.Black tea is a primary source of caffeine, a methylxanthine that stimulates the central nervous system, relaxes smooth muscle in the airways to the lungs (bronchioles), stimulates the heart, and acts on the kidney as a diuretic (increasing urine).