Menhuang (Sealed Yellowing)

Definition

Menhuang (闷黄, "smothered yellowing") is what separates yellow tea from green tea. The leaf is picked and fixed with heat like a green tea, but before final drying it is wrapped in cloth or paper, packed into boxes or piled while still warm and damp. Over hours to a few days, sometimes in several rounds alternating with light drying, the trapped heat and moisture drive non-enzymatic changes in the leaf's polyphenols and chlorophyll. The result is a yellowed leaf and liquor and a softer flavor: less grassy and astringent than green tea, smoother and sweeter, sometimes with corn, bread or light honey notes. Because the enzymes were already stopped during kill-green, this is not oxidation in the sense used for oolong or black tea, and it is not microbial fermentation. Only a handful of Chinese teas are made this way. Junshan Yinzhen from Junshan Island in Dongting Lake, Hunan, is the best known. Mengding Huangya from Sichuan and Huoshan Huangya from Anhui are the other classic examples. Yellow tea production fell sharply in the twentieth century as many makers found green tea more profitable, and some teas sold as yellow tea today skip or shorten the menhuang step.