Black tea belongs to post-fermented tea, which is unique to China. It has a long history of production, mainly in Hunan, Hubei, Sichuan, Yunnan, Guangxi and other places. The main varieties are Hunan Black Tea, Hubei Laobian Tea, Sichuan Biancha, Guangxi Liubao Sancha Tea and Yunnan Pu 'er Tea. Among them, Yunnan Pu 'er tea enjoys a long-standing reputation at home and abroad. ?

Black tea is made from coarse and old raw materials through four primary processes: deactivation, rolling, fermentation and drying. Pile fermentation is the key process to determine the quality of black tea, and the length and degree of time will make obvious differences in the quality and style of finished tea. For example, the accumulation fermentation of Hubei old green tea is carried out after enzyme fixation, kneading and frying. During composting and fermentation, the re-kneaded leaves are piled into small piles, which are tightly packed and compacted to make them undergo biochemical changes at high temperature. When the pile temperature reaches about 60 degrees, turn over the pile, stir it evenly inside and outside, and continue the pile. The total time of stacking fermentation is 7-8 days. When water drops appear in the tea pile, the grass disappears, and the leaves are green or copper in color and uniform, it is moderate and opposed to drying. ?

Black tea pressed tea, such as brick tea, cake tea, Tuo tea and Liubao tea, is an indispensable drink for ethnic minorities.