Yuba is a delicacy in Japan and although not sold in traditional tofu shops is a byproduct from the tofu making process. There are some specialist commercial yuba shops in Japan but a small quantity of it is made each time tofu is made. This is usually eaten fresh by tofu makers and their family or served to special guests or visitors as a treat. On occassions it is set aside and dried to be used later in cooking.
When soy milk is heated to make tofu a thin film, which the Japanese call yuba, appears on its surface in the curdling barrel. Before it solidifies this film has to be picked off to prevent it entering the tofu. If the yuba did this it would make the tofu split and ruin it.
Yuba is best served when fresh and warm. When it is made at home and served in this manner, its quality surpasses yuba made in a traditional shop. Despite many traditional yuba shops being present in Japan, finding one elsewhere in the world is very difficult if not impossible.
Elsewhere in the world this food, which is high in protein and easy to digest, is found dried in Chinese markets where it is sometimes called fupei. It is found in the dried goods section in two different forms. The first of these is in a dried sheet which can be labelled as dried bean curd, bean curd sheets or bean curd skin. This can be used a vegan saugage skin as well as it's traditional uses.
The other form of yuba is u shaped rolls which can be labelled as bamboo yuba or bean curd sticks with five different varieties available in a similar manner to pasta. These varieties are flat sheets, long rolls, short rolls, large spirals and Oharagi.
Sources
news:alt.food.vegan
The Book of Tofu by William Shurtleff & Akiko Aoyagi