Manufacturing method and technological process of yuba
1. Selected raw materials:
The main raw material for making yuba is soybean. In order to highlight the brightness and whiteness of the finished yuba, it is necessary to choose yellow-skinned soybeans instead of green-skinned ones. At the same time, we should also pay attention to selecting fresh soybeans with full grains, Huang Liang color, no mildew and no moth-eaten, removing bad beans, impurities and sand grains through screening to make the raw materials pure, and then putting them into an electric universal mill to remove the bean coat.
2. Soaking bean mill: put peeled soybeans into a cylinder or barrel and soak them in clear water to remove impurities floating on the water. The amount of water is subject to the fact that the bean container is not exposed. Soak in water for about 20 minutes in summer, then pick it up and put it in a laundry basket to drain, cover the bean noodles with cloth and let the bean slices swell. When the temperature is about 35℃, it should be washed with clean water after being soaked in acidic water. If the temperature is below 0℃ in winter, you can add some hot water for 3 to 40 minutes when soaking, drain it and put it in a jar or bucket, and you can also cover it with Gabbana to make its bean slices fat. Through the above method, the pulp can be ground in about 8 hours. When grinding, add water evenly to make the ground soybean milk delicate and white. In the hot summer, protein is easy to deteriorate, so it is necessary to clean off the rancid substances left in various parts of the abrasive tool within 3 to 4 hours after grinding to prevent it from affecting the next grinding.
3. Filter the pulp and put it on the pot:
Pour soybean milk into a vat or bucket and pour it into hot water. The ratio of water, 500 kg of hot water per 100 kg of soybean raw material, stir evenly, then prepare a pot or barrel, and pour the soybean milk into a hanging bag for slurry filtration. You can repeatedly stir the filter cloth with a thin tap cloth to make the soybean milk flow into the cylinder or barrel through the filter cloth eye. After all the soybean milk is filtered out, the bean dregs are evenly spread on the wall of the bag, heated water is stirred evenly, and the bag is continuously shaken and hung for secondary filtration; Accordingly, soybean milk can be drained for the third time. Then pour the soybean milk into a special flat-bottomed iron pot.
4. Boiling and film taking:
Cooking pulp is a key technology in the production of yuba. The operation steps are as follows: first, boil the soybean milk in the pot, immediately stop the furnace and blow, cover the fire with charcoal, coal or sawdust to suppress the flame, so as to reduce the furnace temperature and skim off the white foam on the pot surface. After 5 to 6 minutes, the pulp surface naturally forms a film, which is the yuba film. At this time, cut the petals into two pieces with scissors, and then stir them up along the edge of the pot with a bamboo pole to make the rotten pieces form bamboo. Usually, 4 bamboo poles are prepared for each pot, each bamboo pole is 80cm long, and 20 yuba sticks can be hung. Each pot 15kg can remove 30 pieces of soybean milk, totaling 60 tofu tendons. In the process of uncovering the film when cooking, there are three keys to success: (1) After lowering the furnace temperature, if the charcoal fire or coal fire cannot be connected, or it is too slow, the temperature difference in the pot will be. After stopping blowing, the prepared red-hot charcoal fire must be added to keep the temperature constant. If conditions permit, the boiler steam can be input to the bottom of the slurry pot without direct cooking with fire. (2) If the temperature of the pot does not decrease and continues to boil, the bottom of the pot will be burnt and the output will decrease. (3) When the foam in the pot is not removed, it can directly affect the film formation.
5. Drying into bamboo;
Tofu tendons should be dried but not dried, which is easy to get moldy in the sun. Put the yuba slices on the pot cover into the drying room. There is a drying rack in the drying room, which is 5 meters long and 1 meter high. And set up the stove, hang the dried yuba in the drying room, and keep the fire temperature at 60℃. If the fire temperature is too high, the bamboo feet will be burnt and the color will be affected. It usually dries in six to eight hours. 60-65 kg of yuba can be processed per 100 kg of soybean. After drying, the head and tail are arranged neatly, and can be made into small bags with plastic film bags. Yuba is brittle and belongs to fragile food. During storage and transportation, attention must be paid to prevent heavy pressure and falling. At the same time, pay attention to moistureproof, so as not to affect product quality and reduce economic value. In recent years, in order to solve the fragile problem of yuba products, domestic yuba factories. Before the film formation of soybean milk, 5 grams of methionine and 40 grams of glycerol were added to each kilogram of soybean milk to increase the proportion of amino acids, thus improving the physical properties of yuba, making it not easy to break and increasing the yield. It can be stored at 30℃ for 6 months, keeping the original flavor unchanged.