In most tea regions, tea trees can be harvested all year round but the flavor profile of the final tea will vary depending on the harvest season. Normally, only the young terminal bud with 2-3 tender leaves is plucked. It is the most desirable part of the tea plant, as it contains higher levels of amino acids, including theanine, which gives the tea its characteristic sweetness and reduces its astringency.
The withering process is two-stage. First, the freshly harvested tea leaves are spread out evenly on a canvas outdoors. Experienced tea masters constantly flip the leaves to ensure that they are fully exposed to the air and sunlight. After a few hours of dehydration, the leaves begin to wilt and turn a darker green color. The leaves are then moved indoors to complete the withering process.
The tossing process is important for removing moisture from the leaves and promoting fermentation. The leaves are tossed in a bamboo basket for 10-20 minutes. The tossing time and speed must be carefully monitored to help promote efficient fermentation.
Fermentation is the oxidation process that gives tea its characteristic flavor. There are four main degrees of fermentation: non-fermented, semi-fermented, fully-fermented, and post-fermented. The tea leaves are placed in a room with a constant temperature and humidity level for effective fermentation, the degree of which determines the color, body, and flavor of the tea.
Fixation The fixation process stops the fermentation process by deactivating enzymes. The leaves are steamed at a high temperature of 300° C (572°F) for 8-10 minutes. This process removes astringency and preserves the flavor and aroma of the tea at a desired level.
After fixation, the tea leaves are soft with high tenacity. The damp tea leaves are repeatedly rolled to release their sap and juices and then dried. The drying process is repeated several times until the leaves reach a moisture content of 3%. The shape of the tea leaves, such as spirals, balls, or cones, is determined by the rolling process.
Sophisticated tea color sorting equipment removes impurities and inadequate tea leaves to achieve standardization. This is the
refining stage of tea processing, where the color, size, and quality of every tea leaf is classified before it is packaged.