Step 1, select soybeans, and choose new soybeans that are not moldy, mature, untreated, bright in color, full in particles, moth-eaten and rat-bitten as raw materials;
Step 2: Soaking: firstly, fresh water with the amount of 1.5 times that of soybeans is injected into the soaking pool, and then the soybeans are put into the soaking pool, and the water temperature should be controlled within the range of 15-20℃;
The third step is pulping, commonly known as "grinding". After soybean is soaked, it must be washed with clear water and drained before it can enter the pulverizer for pulping. When grinding, water must be added quantitatively.
Fourthly, residue filtering: adopting the traditional residue filtering method, putting polished soybeans into a filtering tool, and shaking rhythmically to filter out bean residues;
Step 5: Boil the pulp, that is, pour the squeezed raw pulp into the pot and boil it, without covering the pot cover, and skim off the foam on the surface while cooking. The fire should be strong, but not too strong, in case the soybean milk overflows after boiling. Boil soybean milk until the temperature reaches 90 ~ 1 10℃. Insufficient temperature or too long time will affect the quality of soybean milk;
Step 6: Pulping, that is, grinding the burned gypsum into powder, mixing it with clear water into gypsum slurry, pouring it into the soybean milk just scooped out of the pot, and gently stirring it with a spoon. After a few minutes, the soybean milk condenses into tofu flower;
Step 7, squeezing: scoop the bean curd flower into the wooden pallet, wrap it with cloth, cover it with wooden boards, pile up stones, and press all the water to get dried bean curd;
Step 8: Smoke and bake: The extruded dried bean curd needs to be smoked and baked with Jatropha curcas trunk firewood until it becomes hard and uniformly black.