Sun-drying
Definition
Finishing tea leaves by drying in direct sunlight rather than in heated ovens. Sun-drying is essential to Yunnan pu-erh production and is also used in some white and black teas.
Why it matters
Sun-drying, called shai qing in Chinese, is one of the defining steps of pu-erh and certain Yunnan-style teas. After kill-green and rolling, the leaves are spread on bamboo mats and dried under the sun until moisture drops to a stable level. Crucially, the maximum leaf temperature stays well below that of oven drying, so heat-labile enzymes and microbes survive on the leaf surface. This surviving microbial and enzymatic activity is what allows raw (sheng) pu-erh to continue transforming for years or decades in storage, slowly developing the deep, sweet, woody character of aged tea. Oven-dried green teas, by contrast, are essentially sealed and stale relatively quickly. Sun-drying is also used for traditional white teas like Yunnan moonlight white and for some country-style black teas. Weather risk is significant: a sudden rain or extended cloud cover can ruin a batch, which is one reason hybrid solar/indoor drying setups are increasingly common.