1. Tea withering

In the process of withering, the chemical composition of the fresh leaves changes slowly. With the loss of water, the concentration of cell fluid increases, enzyme activity increases, the green smell of tea is partly emitted, polyphenols are slightly oxidized, some proteins are hydrolyzed into amino acids, and starch is decomposed into soluble sugars. These changes are all conducive to the improvement of quality. Due to a small amount of damage to the green color, the leaf color is greenish with yellowish green feeling; the hydrolysis of protein and starch increases the water extract content, while the ratio of polyphenols to amino acids decreases, which makes the tea soup color change mellow.

2. Tea fixation process

During the high-temperature fixation process, the moisture of the fresh leaves quickly vaporizes and evaporates in large quantities, and the low-boiling components with green odor and unpleasant odor are volatile, and the aromatic high-boiling components are revealed; at the same time, under the action of thermophysical chemistry, some new special aromas are formed.

Fresh leaves have high water content and active ingredient content, so they should be stir-fried more when they are fixation to increase the aroma and keep the green; old leaves have low water content and low amino acid content. In order to improve the taste of the tea soup of low-grade leaves, it is necessary Appropriately increase the degree of stuffiness.