1, withering. The first step in making black tea is to wash and wither the tea leaves. This step is to promote the activity of fresh leaf enzymes. The method of withering is very simple, that is, it is spread evenly at a certain temperature and humidity, so that the tea leaves wither naturally or wither after being irradiated by sunlight. In the process of withering, it is normal that the smell of grass in tea decreases or disappears.

2. rub. The purpose of kneading dough is for later fermentation. There are two ways of kneading, one is hot kneading and the other is cold kneading.

Tea leaves are shaped and strengthened in the process of rolling, and at the same time, due to the destruction of leaf cells, it is convenient for necessary oxidation under the action of enzymes, which is conducive to the smooth progress of later fermentation.

3. Fermentation. Fermentation is a unique stage of black tea production. At present, fermentation machines are widely used to control the temperature and time of fermentation. In the process of black tea fermentation, the chemical reaction of polyphenols greatly changes the chemical composition of fresh leaves, which will produce theaflavins, thearubigins and other components.

After fermentation, the color of leaves changed from green to red, forming the characteristics of black tea, red leaves and red soup. If the fermentation is moderate, the color of young leaves will be red and uniform, and the old leaves will be blue in red and have the unique aroma of mature fruits.

4. Drying is the process of baking the fermented tea embryo at high temperature, quickly evaporating water, and achieving dry quality. It has three purposes: using high temperature to quickly inactivate the activity of enzyme to stop fermentation; Evaporate water, reduce volume, fix appearance, keep dry and prevent mildew; Emit most of the low-boiling grass fragrance, strengthen the retention of high-boiling aromatic substances, and obtain the unique sweetness of black tea.