Detailed Explanation of the Dark Tea Manufacturing Process and Processing Methods

The manufacturing process of dark tea consists of fixation, rolling, pile fermentation, and drying. Among these, pile fermentation is a unique step in dark tea manufacturing and the key step that forms the quality of dark tea.

(1) Fixation

Because the leaves picked for dark tea are coarse and old with low moisture content, they require high-temperature quick-frying with fast and even turning until they turn dark green.

(2) Rolling

After the fixation leaves are removed from the wok, they should be rolled immediately while hot, which makes it easier to shape a good appearance. The rolling method is the same as that for ordinary black and green tea.

(3) Pile fermentation

The rolled leaves are piled on a bamboo mat to a thickness of 15-25 cm, covered with a damp cloth and weighted down to retain moisture and heat, carrying out the pile fermentation process. During pile fermentation, the leaves should be turned 1-2 times at appropriate times according to changes in pile temperature.

Regarding the essence of the chemical changes in pile fermentation, there is still no definitive conclusion. Currently, the tea science community has three theories: enzymatic action, microbial action, and damp-heat action, but it is generally believed that the main role is played by hydrothermal action, similar to the yellowing process of yellow tea.

(4) Drying

There are baking methods and sun-drying methods to fix the quality and prevent deterioration.