(1) Remove impurities from soybeans. The moldy beans and stone impurities in the soybeans must be removed to ensure that the beans put into production are pure, fresh, thin-skinned, large and full, clean and free of impurities. For large-scale production, there should be impurity removal equipment, namely a removal machine, which removes impurities from soybeans through mechanical screening, and then uses lifting machinery or raw material conveyors to send the soybeans to the next process.

Soy milk made from peeled soybeans has a better color and flavor than soy milk made without peeling. If the soy milk production process of soaking and grinding after peeling is adopted, the moisture content of soybeans is required to be less than 12% to ensure that the peeling rate is above 90%. When the moisture content of soybeans exceeds 12%, the soybeans should be dried in a dryer at 105 to 110°C, and then peeled after cooling. Soybeans can be peeled using a gear mill, and the spacing is adjusted so that most soybeans can be divided into two halves and the soybean cotyledons will be crushed to a certain degree. After peeling, the difference in gravity between the bean petals and the bean skins is used, and a blower device is used to blow out the bean skins. Soybean skin accounts for about 13% of the weight of soybeans.

(2) Soaking. Soaking soybeans can soften cell tissue to facilitate the extraction of active ingredients. The soaking water should be 3 times the weight of soybean raw materials. The soaking time depends on the water temperature. When the water temperature is below 10°C, the soaking time is controlled between 10 and 12 hours. When the water temperature is between 10 and 25°C, the general soaking time is between 6 and 10 hours. You can also use the method of heating the soaking water. To shorten the soaking time, but the water temperature should not exceed 60℃, an appropriate amount of NaHCO3 can be added to the soaking water to shorten the soaking time, and can better remove the pigments in the soybeans, increase the milky whiteness of the soy milk, improve the homogenization effect, and help Remove oligosaccharides and add trypsin inhibitors to inactivate and improve the flavor of soy milk.

(3) Hot blanching and rinsing. Blanch with waste water or steam to inactivate lipoxygenase and reduce the beany smell. The temperature should be controlled at 95-100°C and the time should be about 2-3 minutes to ensure the stability of the protein and improve the extraction rate.

(4) Extraction and separation by hot grinding. Use hot water above 80℃, add 0.25% NaHCO3, and the amount of water is 8 to 10 times the dry weight of soybeans. Use a separate refiner to separate the slurry from the bean dregs.

(5) Heat treatment and deodorization. The soy milk has been put through a high-temperature sterilization and deodorization machine, which uses 100 to 110°C for instant sterilization to kill pathogenic bacteria and spoilage bacteria, destroy undesirable factors, and inactivate components such as lipoxygenase and urease, thereby removing the fishy odor of soy milk.

(6) High pressure homogenization. At 80°C and a pressure of 15 to 23 MPa, the materials are homogenized to ensure the delicate taste of soy milk and improve the stability of the product.

(7) Packaging. The soy milk is boiled at 80 to 100°C, then bottled, capped, and finally sterilized at 121°C for 30 minutes. After cooling, the finished product is obtained.