Black beans → screening → washing → soaking → draining (TY-II) → cooking → cooling → inoculation → koji making → washing black beans → soaking FeSO4→ mixing salt → fermentation → drying → finished product (dried black beans).
Second, the main points of operation
(1) raw material treatment 1. Selection of raw materials: It is appropriate to select black beans with full maturity, full and uniform particles, thin skin and plenty of meat, no moth, no mildew and deterioration, and a certain freshness. 2. Washing: Wash sand impurities mixed in soybeans for many times with a small amount of water. 3. Soaking: The purpose of soaking is to make black beans absorb a certain amount of water, so as to quickly achieve moderate denaturation during steaming; Make starch easy to gelatinize and dissolve out the nutrients needed by mold; Provide necessary water for mold growth. The soaking time should not be too short. When soybean absorption rate; 95% soybeans will burst and lose their integrity if they absorb too much water, and there will be "koji burning" when making koji. Fermented douchi tastes bitter and is easy to rot and deteriorate. Therefore, the soaking conditions of 40℃ and 150 minutes should be selected in the production and processing, so that the absorption rate of soybean seeds is 82% and the volume expansion rate of soybean is 130%. 4. Cooking: The purpose of cooking is to destroy the internal molecular structure of soybean, so that protein can be moderately denatured and easily hydrolyzed, and the starch can reach the gelatinization level, and at the same time it can play a sterilization role. The cooking conditions were determined as 65438±0 kgf/cm2, 65438 05 minutes or 65438 050 minutes under normal pressure.
(2) The purpose of koji-making is to make cooked beans produce corresponding enzyme system under the action of mold. Rich metabolites are produced in the brewing process, which makes Douchi delicious and unique in flavor.
Take the cooked soybeans out of the pot, cool them to about 35℃, inoculate them with Shanghai Brewing 3.042 or TY-Ⅱ, the inoculation amount is 0.5%, mix them evenly, keep the room temperature at 28℃, and observe them every 6 hours after 16 hours. The first koji-making takes about 22 hours, mainly to loosen koji materials, increase gaps, reduce resistance, adjust product temperature, and prevent koji burning or mixed bacteria pollution caused by temperature rise. The second lap is 28 hours. Turning the song in time can improve the quality of making the song. Premature warping will inhibit the germination of spores, and excessive warping will cause bacterial pollution or koji burning due to the increase of koji temperature. When the starter is covered with hyphae and yellow spores, the starter can be produced. The general koji-making time is 34 hours.
(3) The fermentation of fermented douchi is to decompose protein in beans by protease produced in koji-making process to form a certain amount of amino acids, sugars and other substances, which endows douchi with its inherent flavor.
1. Wash Douchi: There are many spores and hyphae attached to the surface of Douchi koji, which are rich in protein and enzymes. If spores and hyphae are not cleaned, they will remain on the surface of Douchi koji, and some of them will dissolve and hydrolyze after fermentation, but most of them are still attached to the surface of Douchi koji in the form of spores and hyphae, especially the bitter spores will bring bitterness to Douchi and cause dim color.
2. Add soap alum to blacken the beans and increase the brightness.
3. Braising: add 18% salt, 0.02% soap alum and appropriate amount of water to the finished koji, and keep the curved surface uniform, and soak for 12 hours.
4. Fermentation: put the processed bean koji into a jar until it is 80% to 90% full, compact it layer by layer when loading, and put it into a constant temperature room at 28℃ ~ 32℃ for fermentation. The fermentation time is controlled at about 65438 05 days.
(4) taking the air-dried fermented soybean out of the tank and air-drying it in air at a certain temperature to obtain the finished product.
Third, the quality standard
(A) sensory indicators
1. color: dark brown, glossy.
2. Aroma: Maotai and esters are rich and have no peculiar smell.
3. Taste: delicious, salty and delicious, without bitterness.
4. Body: The particles are complete, loose and hard.
(2) Physical and chemical indexes
1. Moisture: not less than18.54%; 2. protein: 2761g/100g; 3. Amino acid:1.6g/100g; 4. The total acid (calculated by lactic acid) is 3.11g/100g; 5. Salt (calculated as sodium chloride)14g/100g; 6. Non-salt solid: 29g/100g; 7. Reducing sugar (calculated by glucose): 2.09g/ 100g.
Douchi is a traditional fermented bean product in China. In ancient times, Douchi was called "secluded" or "addicted". The earliest record can be found in Liu Xi's Interpretation of Famous Foods in the Han Dynasty, which praised Douchi as "the sum of five flavors must exist". There is also a record of "making black beans" in the Book of Songs in the 2nd-5th century. The ancients not only used lobster sauce for seasoning, but also used it as medicine, and attached great importance to it. It is recorded in Han Shu, Historical Records, Qi Yaomin Shu and Compendium of Materia Medica. According to records, the production of douchi was first spread in Taihe County, Jiangxi Province. After continuous development and improvement, Douchi is unique, becoming a favorite condiment and spreading overseas. Taiwan Province Province in China calls Douchi "Shadow Douchi", Japanese people call Douchi "Nachi", and Southeast Asian countries generally eat Douchi.
Douchi can be divided into "black bean Douchi" and "soybean Douchi" according to raw materials. It is better to be dark brown or yellowish brown, delicious, salty and sweet, with sweet residue and the unique fragrance of fermented beans.
Douchi is rich in protein (20%), fat (7%) and carbohydrate (25%), and contains various amino acids, minerals, vitamins and other nutrients needed by human body.
Douchi also increases people's appetite and promotes absorption with its unique aroma. During the War to Resist U.S. Aggression and Aid Korea, China once produced a large amount of fermented soybean for the volunteers to eat.
Douchi can be used not only as seasoning, but also as medicine. Traditional Chinese medicine believes that douchi is flat in nature and slightly bitter in taste, and has the effects of sweating, relieving exterior syndrome, clearing away heat and penetrating rash, relieving restlessness in the middle warmer, relieving depression and detoxifying, and can be used to treat common cold and headache, chest tightness, nausea and vomiting, typhoid fever, food poisoning, etc.
Douchi is widely used in cooking in China. Douchi can be mixed with spices such as sesame oil as a side dish; Cook dishes with lobster sauce and tofu, eggplant, taro, radish, etc. Have different flavors; The famous "Mapo Tofu" and "Fried Pork" all use lobster sauce as seasoning. Cantonese people prefer to use lobster sauce for Cantonese cuisine, such as "lobster sauce ribs", "lobster sauce herring" and red-cooked chicken, duck, pork and beef. Especially when the snails are fried, it tastes better.
It is advisable to seal the fermented beans with ceramic utensils. This can be stored for a long time, and the fragrance will not be emitted. However, it is necessary to avoid the invasion of raw water and prevent the fermented soybean from going moldy and deteriorating.
The famous douchi in China are Yangjiang Douchi in Guangdong, Watermelon Douchi in Kaifeng, Huangyao Douchi in Guangxi, Babao Douchi in Shandong, Tongchuan Douchi in Sichuan and Liuyang Douchi in Hunan.