Tea

The beverage tea is an infusion made by steeping the dried leaves or buds of the shrub Camellia sinensis in hot water. Tea may also include other herbs, spices, or fruit flavors.

An herbal or fruit tea--that is, a tea with no tea leaves in it--is more properly called an infusion or tisane.

Cultivation and Classification

Tea is grown primarily in Mainland China, India, Sri Lanka, Taiwan, Japan, Nepal, Australia, and Kenya. (Note: in the tea trade, Sri Lanka and Taiwan are still referred to by their former names of Ceylon and Formosa, respectively.)

The four main types of tea are distinguished by their processing. Camellia sinensis is an evergreen shrub whose leaves, if not quickly dried after picking, soon begin to wilt and oxidize. 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 this process, and has stuck, even though no true fermentation happens.

Tea is traditionally classified into four main groups, based on the degree of fermentation undergone:

• White tea - young leaves (new growth buds) that have undergone no oxidation.
• Green tea - no oxidation.
  • Kukicha or Winter Tea - Twigs and old leaves, pruned from the tea plant during its dormant season and dry-roasted over a fire. Popular as a health food in Japan and in the macrobiotic diet.
• Oolong (烏龍茶) - whose oxidation is stopped somewhere in-between.
• Black tea - substantial oxidation.
  • Pu-erh (普洱茶) - A subclass of Black tea, Pu-erh is a very unusual product. While most teas are consumed within a year of production, Pu-erh can be over 50 years old. Over this time they acquire an earthy flavour due to the layer of mold that develops on the leaves (or tea brick if they are compressed). The tea is often steeped for long periods of time (Tibetans are known to boil it overnight). Pu-erh is considered a medicinal tea in China.
• Unusual Variations - There are several rarely-encountered tea preparations available (often associated with Traditional Chinese Medicine) which do not fit into the usual nomenclature.
  • Chong Cha (虫茶) - literally "worm tea", this brew is made from the seeds of tea shrubs instead of the leaves. It is used in Chinese medicine for coping with summer heat as well as for treating influenza symptoms.

Processing

Teas are processed in two ways, CTC (crush, tear, curl) or orthodox. The CTC method is used for lower quality leaves that end up in tea bags and are processed by machines. This method is efficient and effective for producing a better quality product from medium and lower quality leaves. Orthodox processing is usually done by hand and is used for higher quality leaves. While the methods employed in orthodox processing differ by tea type, this style of processing results in the high quality loose tea sought after by many connoisseurs.

Varieties

Black tea is usually named after the region of origin: Darjeeling, Assam, Ceylon, etc. Most green teas, however, have kept their traditional Japanese or Chinese names: Genmaicha (玄米茶), Houjicha (焙じ茶), Pouchong (包種茶), etc. White teas produce a delicate liquor that often retains a slight residual sweetness. Green tea and black tea both have antioxidants, but different kinds. Green tea has a majority from catechins, particularly epigallocatechin gallate, whereas black tea has a greater variety of flavenoids. Oolong tea falls in between. It is not clear that the quantity or type of antioxidants present have any effect whatsoever on health.

All types are sold as either "single" teas, meaning just one variety, or as blends.

Adulteration and falsification are serious problems in the global tea trade; the amount of tea sold worldwide as Darjeeling every year greatly exceeds the annual tea production of Darjeeling, which is estimated at 11,000 metric tons.

Blends and additives

There are various teas which have additives and/or different processing than "pure" varieties:

• Lapsang souchong (正山小种 or 烟小种) from Fujian, China, is a strong black tea, which is dried over burning pine, and so winds up with a strong smoky flavor.
• Jasmine tea is spread with jasmine flowers while oxidizing, and occasionally some are left in the tea as a decoration. Many other flowers, including roses and other fragrant blooms, are used as flavouring in tea in China.
• Earl Grey is usually a mix of black teas, with essence of the tropical fruit bergamot added.
• Spiced teas, such as the Indian chai, flavored with sweet spices such as ginger, cardamom, cinnamon, black pepper, clove, indian bay leaf and sometimes nutmeg are common in southern Asia and the Middle East.

Tea-like plants

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