2. Boil the beancurd skin in 35% salt water for about 20 minutes, then cool it and put it in a pre-scalded tank. It is required to use cans that can be completely sealed, such as pickle cans. Put it into the cylinder and seal it, so that the cylinder is isolated from the outside air and placed in a cool and ventilated place. This method can be preserved for more than ten days without deterioration.