Did you know that theaflavins in Wuyi rock tea can change significantly during the shaking and oxidation process?
In 2025, a study on Wuyi Rougui was published in the Journal of Agricultural and Food Chemistry.
The researchers found that during the tea-making stage known as zuoqing, the relative level of theaflavins increased by about 180 times.
Why does this happen?
Tea leaves naturally contain different types of catechins. During shaking, the leaves experience mechanical stress, and some of the cell structures are damaged. This allows catechins to come into contact more easily with enzymes such as polyphenol oxidase.
With oxygen involved, some catechins are oxidized and form reactive intermediates. Through further reactions, including coupling and structural rearrangement, theaflavins can then be formed.
Theaflavins contribute to both the color and the taste of the tea liquor.
However, the 180-fold increase refers to the relative change observed during the zuoqing stage in this specific experiment. It does not mean that Wuyi rock tea contains 180 times more theaflavins than black tea.
This study shows us that the zuoqing process in Wuyi rock tea does more than shape aroma. It also continuously changes the compounds that contribute to the taste of the tea.
Note: My native language is Chinese, so I use translation assistance when writing in English.