Tea is a beverage consisting of an infusion or decoction of the leaves (sometimes mixed with spices, herbs or essences) of a shrub cultivated mainly in Bangladesh, China, Indonesia, Sri Lanka, Japan and Kenya. Tea use and ceremonies are associated with various Far Eastern traditions. Another country famous for its tea consumption is the United Kingdom, where tea is practically a national symbol. Tea has a bitter, astringent flavour and is the world's most widespread beverage after water. Since the 1980s the consumption of "iced tea" has become common; this is primarily an industrial product made from an infusion of tea and bottled, refrigerated and served as a refreshing drink; the most popular types are lemon and peach-flavoured. The six basic types of tea are:
• black tea
• green tea
• Oolong tea
• white tea
• yellow tea
• Pu-Erh or fermented tea
All these varieties come from the leaves of the same plant, but are made by different processes and subject to varying degrees of oxidation (commonly known as fermentation). black teas are fermented teas, green teas are unfermented, and oolongs are semi-fermented. Once dried, the tea can be further processed to create flavoured teas, pressed teas and decaffeinated teas. The term "red tea" commonly refers to hibiscus tea or the South African infusion of rooibos, which do not contain Camellia sinensis.
Tea can be classified on the basis of various factors, such as production area, destination market, size and shape of leaves etc. However, the most important factor distinguishing the end product is the processing method which the leaves undergo after harvest. The main difference is the degree of oxidation of the leaves (commonly known as fermentation); which distinguish: green teas (non-oxidised), black teas (completely oxidised) and semi-fermented teas such as oolong, which fall between the two extremes.
The earliest text references to the consumption of tea in China date back to the 3rd century. Among the greatest promotors of tea were Buddhist monks, who adopted it as a ritual beverage and a tonic. In China, the use of leaf tea was consolidated during the Ming Dynasty, and production began not only of green teas, but also of oxidised and partially oxidised teas. The first reference to tea in a European text is found in a report by Venetian Giovan Battista Ramusio. It is assumed that the Portuguese introduced tea into Europe, but the first imports documented were by the Dutch East India Company. In Europe, tea first became popular in France and the Netherlands. The first establishment to serve tea was Thomas Garway's coffee house in 1657. The British East India Company began importing tea in 1669, and over the subsequent century tea became the most important cargo in English trade with the East. The consumption of tea in Great Britain increased enormously and became a national custom.