According to the Chinese legend, the emperor Shennong learned how to brew the beverage when he was boiling. Tea leaves began to be processed and sold. Lu Yu’s the classic of Tea, published in China, described the cultivation, processing, and use of tea. Tea was introduced by Chinese Buddhist monks into Japan, and tea culture then spread to other tropical and subtropical areas.
Cultivation
Tea plants are grown on tea plantations, called gardens or estates, in areas that have a great amount of rainfall and rich, loamy soil.
Tea plant seeds are planted in a nursery, and when the young trees are between 6 and 18 months old, they are replanted in the garden. Nowadays, however, plants are frequently cloned. The tea plants are pruned periodically in order to maintain a height of about 1 m (3 ft) and to encourage the growth of new leaves. Plants grown at low attitudes produce leaves for commercial use after 2.5 years, and those grown at high attitudes are ready in 5 years. The best leaves are produced at attitudes of 1,000 to 2,200 m (3,000 to 7,000 ft).
Processing
The leaves are hand plucked. Only the smallest, youngest leaves are used to produced tea. The three main types of tea being produced today are black (fermented), oolong (semi fermented), and green (unfermented).
To make black tea, harvested leaves are first dried. They are then roller crushed to break the cell walls and release an enzyme. This process gives the tea its flavor. The leave are spread in a fermentation room to oxidize, which turns them to a copper color. They are finally hot air dried; this stops fermentation and turns the leaves black. The tea is then sieved and graded. Leaf-grade sizes run from pekoe, the coarsest size, to flowery orange pekoe, the smallest.
Green tea is heated before rolling, to destroy the enzyme. The leaf then remains green throughout further manufacture and the aroma characteristic of black tea manufacture does not develop. Gunpowder and young hyson are types of green tea.