Fixation

Fixation — also called 'kill-green' (sha qing in Chinese) — is the pivotal processing step that determines how far oxidation progresses. By applying heat, the polyphenol oxidase and peroxidase enzymes responsible for browning are deactivated. Chinese pan-firing in a hot wok (typically 200-300 degrees Celsius) imparts toasty, chestnut notes and allows the artisan to shape leaves simultaneously. Japanese steaming preserves a fresh, marine, vegetal character by applying moist heat that avoids Maillard browning. The timing and method of fixation define the fundamental character divide between Chinese and Japanese green teas. For oolong production, fixation occurs after the desired oxidation level is reached, locking in the specific flavor profile. White tea uses minimal fixation — gentle sun-drying or low-temperature baking — which preserves the highest level of natural antioxidants among all tea types.