1. Material selection and cleaning:
It is advisable to choose soybeans or black soybeans with full maturity, even granules, thin skin and meat, no pest erosion, no mildew and decay, and a certain degree of freshness. Clean water was used to wash out the sand impurities in soybean for many times. Conditional use of automated fruit and vegetable cleaners to wash black beans in large quantities.
2. Soak black beans:
The purpose of soaking is to make black beans absorb certain moisture so that they can quickly reach moderate denaturation when steaming; to make starch easy to gelatinize and dissolve the nutrients needed by mould; and to supply the moisture needed for the growth of mould. In production and processing, we should choose soaking conditions of 40 C for 150 minutes, so that the absorptivity of soybean grain is 82%, and the volume expansion rate of soybean is 130%.
3. Black bean cooking:
The purpose of cooking is to destroy the internal molecular structure of soybean, to make protein denatured moderately, easy to hydrolyze, to gelatinize starch, and to sterilize it. The cooking conditions were determined to be 1 kgf/cm2, 15 minutes or 150 minutes at normal pressure.
Cool the boiled soybean out of the pot to about 35 C, inoculate Shanghai brewing, the inoculation amount is 0.5%, mix into the room, keep room temperature 28 C, observe every 6 hours after 16 hours. The first turning takes place in about 22 hours during koji making. The main turning is to loosen koji material, increase voids, reduce resistance, regulate product temperature, and prevent burning koji or contamination by miscellaneous bacteria caused by rising temperature. The second revision was performed in 28 hours.
5. Stepwise fermentation:
5.1. There are many spores and mycelia attached to the surface of soybean koji, which are rich in protein and enzymes. If the spores and mycelia are not washed out, the spores have bitter and astringent taste, which will bring bitter and astringent taste to soybean koji, and cause dark color.
5.2. Add alum to make the beans black and brighter at the same time.
5.3. Add 18% salt, 0.02% alum and water to the koji, and soak it for 12 hours with just the right curved surface.
5.4. Put the processed soybean curd into the tank to 80% and 90% full, compact layer by layer, and ferment in a constant greenhouse at 28 ~32 ~C. Fermentation time should be controlled in about 15 days.
6. Douchi drying:
6.1. Drying soybean sauce with automatic dryer. After fermentation, the dried soybean sauce was taken out of the pot and dried with a fully automatic soybean sauce dryer, that is, the finished soybean sauce. The automatic soybean sauce dryer can be connected with feeding machine, and the soybean sauce to be dried can be connected to the top of the soybean sauce dryer to feed automatically. Douchi dryer uses heat pump as heat source, does not need external steam, does not need to use coal-fired boiler based on combustion as heat source, environmental protection and energy saving, no pollution throughout, intelligent control of temperature and humidity parameters and drying time until drying is completed.
6.2. Compared with the traditional technology, the use of soybean sauce dryer has greatly accelerated the production process of soybean sauce and reduced the cost of soybean sauce sun-drying.
The bean air drying equipment of Xi'an Sunda Environmental Protection Equipment Co., Ltd. can be applied to the drying process of most soybean products, such as tofu, dried beans, soybean oil skin, soybean dregs, natto, etc. Santa company can tailor-make all kinds of drying equipment you need according to the needs of customers. The company has experimental machines. Welcome to visit and discuss cooperation.