Of all the crops of which humans have taken full advantage, tea is a unique one. It is not like vegetables and fruits that we eat directly, or like wheat and grapes that are fermented to produce alcoholic beverages, or like grasses and mulberry that are fed to other animals that we use. Tea goes trough special processing, which must preserve some of its original qualities as well as add some elements of spiritual pleasure by human creativity, before it can be used. This is the result of thousands of years of development. From there evolved two distinctive yet related concepts, varieties of tea trees and varieties of tea.
The biological concept of variety refers a category lower than species. Varieties of the same species exhibit minor differences between them, which are often results of different natural environmental conditions and human cultivation.
Tea trees, like all other crops, have evolved into a wide range of varieties through thousands of years of human cultivation, Each of these varieties has its own appearance, quality and adaptability. For example, right now the tea tree variety that is the most suited to grow in the Longjing area is Longjing tea. This particular tea tree variety is result of generations of cultivation and selection.
Meanwhile, during the long evolution of tea use, different types of tea emerged as different processing methods developed, notably the six basic categories named after their colours, which we have mentioned before - green, white, yellow, blue-green, black tea (commonly known as red tea in China), and dark tea (commonly known as black tea in China). The main difference between these types of teas is in the processing technique, and thus came different traditions of tea drinking.
While varieties of tea tree and varieties of tea are different concepts, they are also closed linked. Theoretically, the leaves from any varieties of tea trees can be processed by different techniques and produce different varieties of tea. But in order to produce a genuine famous tea, leaves of a particular tea tree variety must be processed with a particular technique. Since every famous tea variety is closely linked a particular geographical region, the locality heavily influences the quality of the tea. Tea produced with any other tea tree varieties can rarely reach the standard of a genuine famous tea in both appearance and flavour.
For example, Wuyi Yan tea (literally tea from rocks of Mount Wuyi), one of the ten famous teas, is a wiety of blue-green tea or oolong tea. It got its name from the fact that its tea trees usually grow in the rock cracks on Mount Wuyi. Different microclimates on Mount Wuyi produced a series of Wuyi Yan tea. Hie most well-known Da Hong Pao (Big Red Robe) tea initially had only six bushes. The tea trees that are now used for Da Hong Pao production all came from those six bushes through asexual reproduction. They all live in rock cracks in the surroundings with very similar environment. With this kind of highly exclusive production, the unique qualities of Da Hong Pao are guaranted.
Of the six main tea categories, green tea has the largest production and consumption in China. Green tea is an China. Green tea is an unoxidized tea. There are hundreds of green tea varieties. After processing, their shapes vary widely, including curled, straight, beady, needled, flat, flowery shapes and more. The main characteristic of green tea is that it makes a clear brew with fresh green leaves. The most representative green teas include Longjing Tea from Hangzhou and Biluochun from Suzhou, White tea is slightly oxidized. Its main feature is the white hairs on the tender buds. Therefore, the tea tree varieties selected for white tea must have relative more of these white hairs. White tea output is very small. The most famous white tea is the Baihao Yinzhen (Silver Tip Pekoe) from Fujian Province.
Yellow tea is mildly oxidized. It makes a yellow brew with yellow leaves. Initially, yellow tea was. discarded as inferior products from improperly processed green tea. Green tea enthusiasts thought yellow tea was worthless. But some people appreciated the unique colour and flavour of yellow tea, and gradually it became its own category. Yellow tea output is not very big either. The characteristic yellow tea is Junshan Yinzhen (Junshan Saver Tip) produced on Junshan island on Lake Dongting in Hunan province.
Blue-green tea, better known as oolong tea, is a half oxidized tea. Its oxidation level is between that of green tea and black tea, but can vary widely, ranging from 20 to 70 percent. Therefore there are different varieties of oolong tea, differentiated by their oxidation level -lights medium, or heavy. Oolong tea is particularly popular in Southern China and Taiwan. Da Hong Pao and Tieguanyin (Iron Bodhisattva of Mercy) are both famous oolong teas.
Black tea, which is known as "red tea" in Chinese, has the largest consumption in the world It is wholly oxidized. Its brew can be red as wine. Black tea was developed based on oolong tea techniques. It can be divided into Souchong, kongfu, and fragmented black tea three categories. Fragmented black tea was invented in the 1920s in India and Sri Lanka,where tea leaves were first cut into fragments. Now fragmented black tea is the main material for tea bags around the world-Dark tea, which is known as "black tea" in Chinese, is a post-fermented tea. It should not be confused with black tea, It was first developed during transportation on the Ancient Tea-Horse Road, Because the packaging materials in those days were not waterproof, tea sacks absorbed moisture during the unfavourable transportation conditions. This induced chemical reactions within the tea leaves, causing the tea quality to change dramatically, The seemingly spoiled flavour was gradually accepted by the tea drinker living at the frontier and dark tea became its own category. The most famous dark tea is the famous Pu'erh tea.
The six basic tea categories differ in the oxidation levels of tea polyphenol. Unoxidized tea polyphenol is colourless, which is why unoxidized green tea only displays the green colour of chlorophyll. As the level of oxidation increases, tea polyphenol is oxidated into polymers containing different pigments,which are collectively allied tea pigments.
Based on these six tea categories, through the long history of development, aided especially by modern industry, various new processed tea varieties developed. They can also be divided into six categories, including compressed tea, flower tea, medicinal tea, fruit tea, extract tea, and other beverages containing tea.
Compressed tea is a concept relative to loose leaf tea. It uses ail types of loose leaf tea as material and steam compresses into solid shapes. Depending on the confessed shapes, there are cake tea, brick tea, and tuo tea. Compressed tea is better for storage and transportation. But it also destroys the opportunity to appreciate of the leaf shapes, So high grade green teas, which put much emphasis on leaf shapes, are never compressed.
Other types of processed tea beverages are processed using modern or traditional methods, either exacting tea juice, or mixing in other materials and creating new drinks. No matter how they are processed, one principle never changes: never mess with the original ingredients and flavours of the six basic tea categories with chemical methods. Otherwise, such beverages can no longer be called tea.