Yuba

Tofu skin, yuba, beancurd skin, beancurd sheet, or beancurd robes is a food item made from soybeans. During the boiling of soy milk, in an open shallow pan, a film or skin composed primarily of a soy protein-lipid complex forms on the liquid surface. The films are collected and dried into yellowish sheets known as tofu skin. Since tofu skin is not produced using a coagulant, it is not technically a proper tofu; however, it does have a similar texture and flavor to some tofu products. Tofu skin's use was first documented in written records in China in the sixteenth century. It is widely used, fresh, fermented, or dried, in Chinese, Korean, and Japanese cuisine. An early written reference to tofu skin appeared in 1587 in Japan in the Matsuya Hisamatsu chakai-ki [Three-generation diary of the Matsuya's family's tea ceremonies]. The writer, Matsuya Hisamasa, states simply that tofu skin is the film that forms atop soymilk.

Source: Wikipedia