Fixation (Kill-green)

杀青

Heat application to deactivate polyphenol oxidase enzymes, halting oxidation and preserving the leaf's green color and fresh character. This is the defining step that separates green tea from oxidized teas. Methods include pan-firing (chao qing, most Chinese green teas), steaming (zheng qing, Japanese green teas), baking, and sun-drying. Pan-firing at 200-280°C creates toasty, nutty notes; steaming at 100°C preserves a more vegetal, marine character. The timing and temperature of fixation profoundly influence the tea's final flavor.