The practice of unification of bean curd is to grind soybeans finely and put them into a cauldron to cook into soybean milk, then pour the soybean milk into a flat pot stove with a small fire, and the soybean milk congealed into the viscosity of soybean skin after picking up and drying can be. And the soybean residue has become the top feed for pigs. Putian Hanjiang someone thought of a trick, with soybean oil, and then the dregs of soybean with a pulverizer crushed made of soybean skin ... This reduces the cost of roti!