Yuba is the delicate film that forms and is lifted from the surface of simmering soy milk — the skin of the soybean (Glycine max), a prized soy product of China, Japan and Korea for over a thousand years. Known as fu zhu or dòu pí in Chinese, yuba (湯葉) in Japanese and dubu-pi in Korean, it is soy milk's richest, most concentrated form: as the milk steams, its proteins and oils bond into a thin sheet that is skimmed off, then eaten fresh and silky or dried into pale golden sheets, sticks and knotted rolls. Faintly nutty, beany and subtly sweet, with a supple, tender-chewy bite when fresh and a meaty, sauce-drinking chew when dried and rehydrated, it is the everyday backbone of Buddhist mock-meats, hotpot, braises and rolls.