Withering

Withering is critical for every tea type except steamed Japanese greens, which skip this step to preserve maximum freshness. During withering, fresh leaves are spread on bamboo trays, mesh screens, or withering troughs through which warm air circulates. As cellular moisture evaporates, enzyme activity increases, proteins begin breaking into amino acids, and starch converts to simple sugars. These biochemical transformations create the flavor precursors that will later develop during oxidation and drying. Indoor withering in controlled environments (common in Sri Lanka and India) uses fans and heated air for consistency. Outdoor or solar withering (used for white tea and some Chinese teas) relies on ambient conditions, introducing variability but often a more complex result. The degree of withering — measured by weight loss — is calibrated to the tea type: light withering for green tea, heavy withering for black tea and oolong.