Enryaku-ji's yuba arrives fresh daily from Mount Hiei Yuba, a 71-year-old shop in the town of Otsu, where, in a process that has remained virtually unchanged since Chinese monks introduced it to Japan ten centuries ago, soybeans are soaked in freshwater, then ground and strained to produce milk. As the milk is steam-heated to 190°, strands of denatured protein entangle at the surface, trapping molecules of fat to make a durable, delicious film. It takes about ten minutes for the yuba to form. Workers pull the skin back by hand and insert a stainless steel rod under one edge to lift the yuba off the surface of the liquid in an even sheet. The sheets are hung to cool and dry before being packaged fresh, or are hung longer to be sold as dried yuba, which is used, among other things, for vegetarian mock duck.