Malt manufacturing
There are the following six processes. Barley storage: the newly harvested barley has a dormant period and low germination ability, so it should be stored and ripened. Barley selection: remove impurities by wind and screen, and screen into first, second and third grades according to the size of wheat grains. Wheat soaking: Soak in water for 2-3 days in a wheat soaking tank, and wash at the same time to remove floating wheat, so that the moisture (wheat soaking degree) of barley reaches 42-48%. Germination: the soaked barley germinates under the condition of controlled temperature and ventilation to form various substances, so as to dissolve the contents of wheat grains. The suitable germination temperature is13 ~18℃, the germination period is 4 ~ 6 days, and the elongation of root buds is1~1.5 times of the grain length. The grown wet malt is called green malt. Baking: the purpose is to reduce moisture, stop the growth and decomposition of green malt, so as to store it for a long time; Make malt into substances that give beer color, fragrance and taste; It is easy to remove roots and buds, and the moisture content of roasted malt is 3 ~ 5%. Storage: after baking, the malt is removed, selected, cooled and stored in concrete or metal silo.
brewage
There are the following five processes. It mainly includes three processes: saccharification, fermentation and wine storage and ripening.
Raw material crushing: malt and rice are respectively crushed by a crusher to a crushing degree suitable for saccharification operation. Saccharification: the crushed malt and starch auxiliary materials are mixed with warm water in the gelatinization pot and saccharification pot respectively, and the temperature is adjusted. The saccharifying pot is maintained at the temperature suitable for protein decomposition (45 ~ 52℃) (protein stop). After the fully liquefied mash in the gelatinization pot is put into the saccharification pot, it is maintained at a temperature (62 ~ 70℃) suitable for saccharification (β-starch and α-starch) (saccharification stops) to make malt mash. There are two methods to increase the temperature of mash: leaching method and boiling method. Protein, saccharification pause time and temperature rising method: according to the nature of beer, raw materials and equipment used, it is decided to filter wort with a filter tank or filter, then boil it in a boiling pot, add hops, adjust the wort concentration to a proper level, then enter a rotary sedimentation tank to separate out the thermal coagulum, and the clarified wort enters a cooler to cool it to 5-8℃. Fermentation: adding yeast into the cooled wort, sending it to a fermentation tank or a cylindrical conical bottom fermentor for fermentation, cooling with a snake tube or a jacket and controlling the temperature. During the following fermentation, the highest temperature is controlled at 8 ~13℃, and the fermentation process is divided into foaming period, high foaming period and low foaming period, and the fermentation usually lasts for 5 ~10 days. The fermented beer is called tender beer, which is bitter, rough and low in CO2 content, so it is not suitable for drinking. Post-fermentation: In order to make the tender beer post-mature, send it into a wine storage tank or continue to cool it to about 0℃ in a cylindrical conical bottom fermentor, and adjust the pressure in the tank to dissolve CO2 into the beer. The storage period of wine is1~ 2 months. During this period, the remaining yeast, cold coagulum, etc. are gradually precipitated, the beer is gradually clarified, CO2 is saturated in the wine, and the taste is mellow, so it is suitable for drinking. Filtering: In order to make the beer clear and transparent and become a commodity, the beer is clarified and filtered at-1℃. The requirements for filtration are: large filtration capacity, good quality, less loss of wine and CO2, and no influence on the flavor of wine. The filtration methods include diatomite filtration, cardboard filtration and microporous membrane filtration.
Beer filling
Filling is the last process of beer production, which has a direct impact on maintaining the quality of beer and giving it the appearance and image of beer. The beer after filling should meet the hygienic standard, so as to minimize the loss of CO2 and reduce the air content sealed in the container.
Barrel: the material of the barrel is aluminum or stainless steel, and the capacity is 15, 20, 25, 30 and 50l. Among them, 30l is a common specification. Barreled beer is generally unpasteurized draught beer. Draught beer has good taste and low cost, but its shelf life is not long, so it is suitable for local sales.
Bottle: In order to maintain the quality of beer and reduce the influence of ultraviolet rays, brown or dark green glass bottles are generally used. Empty bottles are soaked in a bottle soaking tank (alkali solution 2 ~ 5%, 40 ~ 70℃), then washed by a bottle washer, then filled with beer by a filling machine, and capped by a capping machine. After pasteurization by a sterilizer, it can be packed and shipped out of the factory after passing the inspection.
Canning: Canned beer started in America on 1935. In the second world war, it developed rapidly because of military supplies. After the war, after a series of technical transformation, the demand gradually increased. 1966, the ratio of bottled to canned in the United States has been 52: 46. The tank body is made of aluminum or copper. Canned beer is light in weight and convenient to transport, carry and open for drinking, so it is very popular with consumers and develops rapidly.
PET (Polyethylene Terephthalate) plastic bottle: It has been put on the market since 1980, and the number is increasing year by year. Its advantages are high transparency, light weight, re-sealing after unsealing and reasonable price. The main disadvantage is poor gas retention, and CO2 gradually decreases during storage. Adding coating can improve gas retention, but the storage time should not be too long. PET bottles cannot be evacuated or pasteurized in advance, and special filling procedures are needed to avoid air intake and contamination of miscellaneous bacteria.
New technology of beer production
There are mainly seven kinds. Thick mash fermentation: 1967 began to be used in production. It is a method of fermenting wort with high concentration and then diluting it into finished beer with specified concentration. It can increase the output without increasing or increasing the production equipment. The concentration of wort is generally about16 p. Rapid fermentation: by controlling the fermentation conditions, the fermentation period is shortened, the utilization rate of equipment is improved and the yield is increased on the basis of maintaining the original flavor. The control conditions of rapid fermentation process are: increasing temperature at a certain stage of fermentation process; Increase the inoculation amount of yeast; Stir. Continuous fermentation: 1906 there was a scheme of beer continuous fermentation, but it was not industrialized until 1967. The main application countries are New Zealand, Britain and so on. The popularization of beer continuous fermentation technology is limited due to the problems of easy variation of strains, pollution of miscellaneous bacteria and beer flavor. Study on the production of beer by immobilized yeast: the research began in the 1970 s, aiming at greatly shortening the fermentation cycle. In essence, it is to overcome the problems of strain variation and miscellaneous bacteria pollution, and it is a faster continuous fermentation process. The results obtained are as follows: the pre-fermentation is shortened from 5 ~ 1 0 day in the traditional method to1day, and it can run continuously and stably for 3 months. Cylindrical conical open-pit fermentor: 1966 has been used in production. Its main advantages are: shortening the fermentation period, saving investment, simple and convenient recovery of CO2 and yeast, and facilitating automatic control. At present, it is very common that the volume of a single tank is 600Kl, and the material is generally stainless steel. Development of draft beer: With the success of sterilization, filtration and aseptic packaging technology, draft beer which can be preserved for a long time without pasteurization has been developed since 1970s. Because of its good taste, it is very popular with consumers. At present, draft beer accounts for 50% of the total beer production in some countries. Development of low-alcohol and alcohol-free beer: a cool drink for car drivers, women, children and the elderly. It is characterized by low alcohol content. The alcohol content of alcohol-free beer is generally 0.5 ~1%,which is rich in foam, light and refreshing in taste, and has a good hop flavor, maintaining the characteristics of beer.