Commercially, Yuba is made in small vats, maybe about a foot by 1 1/2 feet (45 cm) wide. The soy milk has to be heated for about 20 minutes for the film to form on top. The skin is then removed with bamboo poles. The professionals fish it off all in one sheet with perfect edges. The Yuba is then hung to dry, and sold either in folded sheets or wrapped up in small batons. When dry, Yuba is somewhat yellowy and flaky, reminiscent of dried corn husks.
Dried Yuba is almost always used in some form of cooked dish. The sheets can be used to wrap other food in. You can make packets of food that you then steam or fry. The sticks can be fried to be eaten on their own, or broken into pieces to be used as an ingredient. They are often broken into small pieces (1 to 2 inches / 2.5 to 5 cm) and popped into soups. Once rehydrated, Yuba is chewy.
In Japanese restaurants, you can order fresh Yuba. Pots of soy milk are brought to your table over a burner to heat the milk. You fish the Yuba off as it forms with chopsticks, and eat it fresh, dressing it up with a dash of soy sauce and perhaps a few garnishes. Fresh Yuba has a very delicate texture.
After all the soy milk has gone up into the making of Yuba, a thin red film will be left on the bottom of the pot. This is called “Sweet Yuba”, and is also considered very good. You gather it up and serve it along with the rest of your yuba. In Japanese, this is called “amayuba.”
Rehydrate dried sheets by covering them with a wet towel. Rehydrate the dried sticks by soaking them in water.
To make your own at home, start with 1 quart (1 litre) of unsweetened, unflavoured soy milk. Pour it into some pan for which you can really control the temperature, such as a double-boiler on the stove top or an electric frying pan. The pan only needs to be 1 1/2 to 3 inches (3.5 to 7 cm) deep, but should be about 12 inches (30 cm) wide.
Pour in about 1/2 an inch (1 cm) of soy milk. Bring the heat to about 175 F (80 C). After about 7 minutes, a skin will start to form on top. Give the skin a few minutes after that to fully form. If there is no skin by 15 minutes, your heat is perhaps a bit too low. You should have a new skin every 7 minutes or so. The skins will form faster as there is less and less soy milk in the pan.
Put a chopstick or knife under the skin, and twirl the skin up onto the chop stick. Put on a plate or in a small bowl to eat.
If you put in more soy milk, say about 1 inch (2.5 cm) in depth, you will have a new skin about every 12 minutes.
The sheets you make at home are likely to be quite raggedy and won’t have the perfect edges that the experts can produce.
Don’t freeze fresh Yuba; it gets really tough after cooking if you do.
The technique originated in China. Introduced to Japan sometime before 1000 AD.
The fresh sheets are called “Tau Pau” in Chinese, and “Nama Yuba” or “Hikiage Yuba” in Japanese.
Dried Yuba is called “Fu Chook” in Chinese, and “Hoshi yuba” or “Kanso” in Japanese.