I. Introduction
Saccharification of beer lees, also known as beer lees, is a by-product of the brewery. According to the production of 1 ton of beer, 0.17 tons of lees will be produced. Therefore, the development and utilization of this resource has always been the subject of beer industry research. The nutritional value of beer lees is relatively high, and its nutritional components are: protein 24% ～ 28%; fat: 8% ～ 11%; fiber: 55%～61%; sugar content: 1% ～ 3%; ash content: 3% ～ 5 %. Fresh brewer's grain contains 9.68% starch, 10.8% total sugar, 3.5% crude protein and 70% moisture. It is mainly used as feed for cattle and pigs and can be used to obtain malt protein feed after removing the bark and drying. But the use of brewer's grains for vinegar is still a new way. The author chooses beer lees with a certain proportion of corn flour to make koji through double strains. On the one hand, the fresh beer lees replace part of the filling material—rice husk, and on the other hand, the protein in the beer lees is decomposed. Increasing the amino nitrogen in vinegar improves the quality of vinegar. This not only reduces the consumption of vinegar and grain, but also makes full and effective use of the resource of brewer's grains and reduces environmental pollution. It is a production technology worth promoting.
Ⅱ. Raw materials and equipment
raw material:Fresh beer lees, corn flour, bran, rice husk, Aspergillus niger (AS3.350), Aspergillus oryzae (AS3.951).
Equipment: ventilated koji making pool and vinegar making equipment.
Ⅲ. Process flow and operation
Process flow
Operation points
First mix 200 kg of beer lees with 25 kg of corn flour and 36 kg of bran and mix well, pile up the moisturizing material, generally 6-8 h in spring and autumn, 8-12 h in winter, and 2 to 4 h in summer. The moistened material is steamed under normal pressure for 1.5 to 2 hours, and then simmered for 30 minutes.Cool the clinker out of the pot and cool it to 40 ℃. Connect with AS3.350 Aspergillus niger and AS3.951 Aspergillus oryzae. The inoculum amounts are 0.35% and 0.1% of the raw material weight respectively. After mixing, enter the pool and cultivate at 30 ～ 35 ℃ with ventilation for 26 ～ 28 h, Serve the song. Add koji material and proper amount of water to make the made fermented mash with 62%-65% water.Put the fermented mash into the fermenting tank for compaction, seal it with plastic film, and control the temperature of the product in the tank at 22-24 ℃ not exceeding 33 ℃.When the product temperature exceeds 35 ℃, measures should be taken to invert the tank, and the mash should be compacted and sealed after each inversion.The fermentation cycle is 7 to 8 days, and the alcohol content of the mature mash is 6% to 7% (VV).Mix the mature mash with 26 kg of bran, 32 kg of rice husk and 80 kg of water, mix it into acetic acid fermentation mash, put it in a shallow tank, leave it open for 8-10 h, and then put it into the last batch for 3 to 4 d fermentation Mix 1% of the hot vinegar mash, pile into a convex shape, and cover with 1 cm thick fresh vinegar mash. On the first day, the product temperature rises to 40 ℃, and the mash is turned, and then the vat is turned once a day. The mash temperature is controlled at 42 ～ 44 ℃ in the early stage, 38 ～ 40 ℃ in the middle stage, and about 36 ℃ in the later stage. , The acetic acid content is more than 5g100 mL, indicating that the fermentation has basically ended. Add salt to the vinegar in time, mix well, and stack it for another day before ripening. Take 60% mature vinegar mash, and use the three-step drenching method to pour the vinegar. Soak the vinegar for 10-12 hours. The first vinegar is used for soaking the smoked mash, and the second and third vinegars are used for soaking the vinegar.The remaining 40% mature vinegar is placed in the mashed vat, the mouth of the vat is covered, heated to 70 ～ 80 ℃ with a slow flame, and the vat is poured every 24 h for a total of 5 d. The first vinegar is flavored with spices, and then boiled Sterilize for 5 to 10 minutes, soak the smoked mash for 3 to 4 hours, and then vinegar for several months. 7、Preparation and sterilizationMix the aged vinegar and the newly leached head vinegar according to the quality standard before leaving the factory. For general vinegar with a total acid content of less than 5%, add 0.06% to 0.1% sodium benzoate while heating and sterilizing. , Sterilize at 80-90 ℃ for 15-20 minutes to get the finished vinegar.
Ⅳ, physical and chemical indicators
Total acid (calculated as acetic acid): 4g100 mL; Concentration: 7°Be′; reducing sugar > 3g100 mL; amino acid > 0.35g100ml; all hygiene standards meet the requirements of GB 2719-81.
