After withering and fermentation, tea leaves undergo the fixation process (also known as “kill-green” or pan-firing). The purpose of this step is to use high heat to halt the fermentation process. In addition to stopping fermentation, it also eliminates the grassy odor of the tea leaves, breaks down the stems and leaves, and makes the tea leaves much softer.
There are two main methods of fixation: steaming and pan-firing. Pan-firing is more commonly seen in Taiwan. In the past, pan-firing was done using a large stove and wok, with manual tossing and stirring, much like cooking a stir-fry, which is why it was traditionally referred to as “stir-frying tea leaves.” Today, specialized fixation machines are used to handle pan-firing and tossing all at once. They also feature timed and temperature-controlled settings, ensuring much more consistent tea quality.
The temperature for tea leaf fixation generally ranges between 250 and 300 degrees Celsius, and is continued until the leaves feel slightly dry to the touch.