Black tea belongs to post-fermentation tea. The so-called post-fermentation means that tea leaves are treated at high temperature and then piled up for fermentation. In the post-fermentation process, due to the effect of damp heat and microorganism, a series of changes have taken place in the substances in tea. The color of tea gradually deepened from green to dark brown, and the taste became rich, eliminating the rough taste and eventually becoming black tea.

The basic technological process of black tea is enzyme fixation, primary kneading, pile fermentation, secondary kneading and baking. Generally, the raw materials of black tea are coarse and old, and it is often accumulated and fermented for a long time in the production process, so the tea leaves are oily black or dark brown, so it is called black tea. Black tea is the main raw material for pressing all kinds of pressed tea. Black tea can be divided into Hunan black tea, Hubei old green tea, Tibetan tea and Yunnan-Guangxi black tea due to different producing areas and techniques.

Extended data:

Black tea is dried on a seven-star stove. The loose firewood burns on the ground of the stove mouth, and the loose firewood is placed horizontally, and the firepower is kept uniform. The temperature of the fire was evenly penetrated into the Seven Star Cave by the wind, and the temperature of the fire spread evenly to the baking curtain on the stove surface.

When the temperature on the drying curtain reaches above 70℃, sprinkle the first layer of tea blank with a thickness of about 2-3cm. When the first layer of tea blank is 60% to 70% dry, the second layer is sprinkled with slightly thinner leaves, so that it is added to 5-7 layers layer by layer, and the total thickness does not exceed the height of the baking frame. When the top tea blank is 70% to 80% dry, it is annealed and baked.

Bake with a special iron fork, turn the dry bottom layer to the top, and turn the dry top layer to the bottom. Continue to raise the fire and bake until the upper, middle and lower layers of tea are moderately dry, that is, the next baking.