Tea enthusiasts often notice that some Pu-erh teas have cloudy liquor. Besides the tea being relatively new, the kneading process is a crucial factor. Both hot kneading and heavy kneading can cause the tea liquor to become cloudy.
Hot kneading, done to make the dry tea more aromatic and visually appealing, breaks down the tea leaf cells and causes the cuticle layers to fragment and fall off, inevitably leading to cloudy liquor. Kneading is an essential part of Pu-erh tea processing and has a significant impact on the tea's later storage and transformation. The primary purpose of kneading is to apply force to the leaves, breaking the cell walls and allowing some tea juice to seep out. This increases the surface viscosity of the leaves and adjusts the concentration of water-soluble substances, thereby affecting the final brewing concentration of the tea. By breaking the cell walls, kneading allows tea polyphenols, catechins, and other beneficial compounds to polymerize, providing the opportunity for post-fermentation in the future.
Tea leaves that have not undergone proper kneading have intact cell walls, preventing the release of internal beneficial compounds. These leaves are less likely to interact with oxygen and beneficial microbes, hindering subsequent transformation. Kneading itself is a highly skilled process requiring experience. For instance, to achieve a rich tea liquor, a stronger kneading force and longer kneading time are needed. However, for teas known for their fragrance, heavy kneading is not recommended. Kneading is both necessary and indispensable.
Experienced tea makers often adjust the kneading intensity based on the characteristics of the fresh leaves. However, some practices aimed at maintaining the integrity and appearance of the leaves often result in insufficient kneading. In reality, proper kneading can stimulate the internal substances of the tea, making it suitable for subsequent transformation.