Yuba (bean curd skin) (ゆば)
Yuba is a processed food made from soybeans. When soy milk is brought to boil, due to the Ramsden phenomenon a film or skin forms on the surface, which is lifted with utensils such as bamboo skewers. That protein-rich film is referred to as yuba, and is a popular ingredient for vegetarian cuisine.
It is said that yuba as an ingredient for vegetarian cuisine was seen for the first time in Japan approximately 1200 years ago, when Saicho brought it back from China along with Buddhism and tea. The first yuba in Japan was introduced to the Grand Head Temple of the Tendai sect Enryaku-ji Temple at Mt. Hiei, located between the present Kyoto City, Kyoto Prefecture and Otsu City, Shiga Prefecture.
According to some historical records remaining today, there was an old children's song in Sakamoto at the base of Mt. Hiei, the lyrics of which included a passage saying, 'what do those monks on the mountain eat, Grilled yuba and pickled vegetables.'
Kyoto City and Omi (the present Otsu City, Shiga Prefecture) at the base of Mt. Hiei, where yuba was first introduced in Japan, along with Nikko City and Minobu Town, are well known as production centers of yuba.
In Kyoto and Minobu, yuba is written with kanji representing '湯葉 (leaves of hot water),' whereas in Nikko, it is written with kanji meaning '湯波 (ripples of hot water).'
In Japan, they call yuba lifted from boiling soy milk fresh yuba (or hikiage – lifted - yuba) and, aside from using it as an ingredient for cooking, eat it as is without cooking, which is referred to as 'yuba sashimi.'
Yuba is also often used in Fucha-ryori cuisine (Chinese-style Buddhist vegetarian cuisine).
In Kyoto, since they slip the skewer underneath the outer edge of yuba to lift it, yuba comes out in single-sheet form. In Nikko, on the other hand, they slip the skewer underneath the center of yuba to lift it, yuba comes out folded in two. In view of the above, the Kyoto yuba is thin, whereas, the Nikko yuba is more substantial.
Yuba is available in various forms including dried yuba as well as yuba which has been made into a roll or knot while it was partially dry. Rolled yuba is often used in soup, whereas yuba sheets are often softened by soaking in warm water prior to being used for making various bean curd sheet rolls.
In China, yuba comes predominantly as either 'fupi' (fǔpí), which is dried yuba sheets, or 'fuchu' (fǔzhú), dried yuba sticks made by wringing fresh yuba into the stick shape, and it is very seldom available in the roll form that is common in Japan. Yuba in the form of knots, called 'fupijie' (fǔpíjié), is made in China.
Hangzhou City, Zhejiang Province, is well known as the production center of 'fupi' yuba, with one of the signature dishes of the region being 'tsuijartialing' (cuìzháxiǎnglíng), which is deep fried yuba.
Among the Cantonese dim sum dishes common in Hong Kong and Guangzhou City, sin jyut gyun (tofu skin rolls), sin jyut zaat (tofu skin rolls) and fu pei gyun (tofu skin rolls) are popular. These are tofu skin rolls stuffed with various ingredients including pork, shiitake mushrooms and carrots all cut to matchstick size and then cooked in the sauce made with oyster sauce and other seasonings. Then the tofu skin rolls are steamed in a bamboo steamer before being served.
Fuchu' is produced in various locations in China including Kanan Province where it is known as Changge fuzhu (the yuba of Changge City), Hunan Province where it is known as Yongxing fuzhu (the yuba of Yongxing Prefecture) and the Municipality of Guangxi Zhuangzu where it is known as Guilin fuzhu (the yuba of Guilin City). It is common for 'fuchu' to be softened by soaking in hot water prior to cooking in sauce or use in hot pot cooking.