1. Select high-quality pollution-free soybeans without heat treatment. The new soybean with bright color, full seeds and no insect bites is the best. Newly harvested soybeans are not suitable for use and should be stored for 3 months before use.

2. Water volume: The soaking volume is generally 2-2.5 times that of soybeans. Do not add enough soaking water at one time. It is appropriate to soak the surface of the material about 15CM for the second time. When the soaking water level drops to 5-7 cm below the material level.

3. The boiling temperature should be controlled above 97 degrees Celsius for about 3 minutes. Add 3 defoamers and heat evenly. When the temperature of the pulp reaches 75 degrees Celsius, you can order the pulp.

4. Using salt water as coagulant, protein has a fast solidification speed, so don't master the operation. Take 5kg of dried beans as an example. Before discharging, sprinkle about 60g of salt on the bottom of the barrel. When the temperature drops to 85 degrees Celsius, pour the soaked salt water in 2-3 times. The amount of bittern is 50-70g. Soak 50g of dried bittern slices in warm water and add a little tofu (about 35g).

5. Press the pressure rod to the third or fourth pressure, then stop the flow for 3-5 minutes, and lift the manual hydraulic mechanism to expose the finished product. The bean skin made from it is not only hygienic, but also delicious, well-preserved in texture and even in thickness.