1, black tea, English black tea. During the processing of black tea, a chemical reaction centered on the enzymatic oxidation of tea polyphenols took place, and the chemical components in fresh leaves changed greatly. Tea polyphenols decreased by more than 90%, resulting in new components such as theaflavins and thearubigins. Compared with fresh leaves, the aroma substances increased obviously. Therefore, black tea has the characteristics of black tea, red soup, red leaves and glycol.

2. Black tea is a kind of fully fermented tea, which is refined through a series of technological processes such as withering, rolling (cutting), fermentation and drying. Withering is an important process in the primary processing of black tea, which is called "black tea" in the primary processing. Black tea is named after the tea soup and leaf background color are red after brewing dry tea.