The processing of green tea is simply divided into three steps: fixation, rolling and drying, the key of which is fixation. The fresh leaves are inactivated and the enzyme activity is inactivated. The various chemical components contained therein are basically subjected to physical and chemical changes under the condition of no enzyme influence by the action of heat, thus forming the quality characteristics of green tea.

Fixation plays a decisive role in the quality of green tea. Through high temperature, the properties of enzymes in the fresh leaves are destroyed, and the oxidation of polyphenols is prevented to prevent the leaves from reddening; at the same time, part of the water in the leaves is evaporated, making the leaves soft, creating conditions for rolling and shaping. With the evaporation of water, the low-boiling aromatic substances with grassy aroma in the fresh leaves volatilize and disappear, thereby improving the aroma of the tea.

Except for special teas, this process is all carried out in a fixation machine. The factors that affect the quality of the fixation include the fixation temperature, the amount of leaves, the type of the fixation machine, the time, and the fixation method. They are a whole and are interrelated and restricted.

Affected by the varieties of tea, the methods of fixation are also different, including fried fixation, sun-dried fixation, and steamed fixation.