Views: 0 Author: Site Editor Publish Time: 2022-05-07 Origin: Site
Craft beer has very high requirements on the brewing environment during the brewing process. If you are not careful, it will cause the invasion of heterogeneous microorganisms. The growth and reproduction of these microorganisms use the nutrients in wort (very good medium) or beer. Causes beer to appear precipitation, turbidity, and even its metabolites lead to beer flavor and taste variation. Let me share with you a few processes that are easy to contaminate in the beer brewing process:
1. First of all, in the mashing stage, the types of bacteria susceptible to infection are: Lactobacillus thermophilus. At the beginning of mashing, when the mash temperature is less than or equal to 50 °C, it is easy to dye, but it is beneficial to reduce the pH of the mash; above 50 °C, lactobacillus is not easy to grow.
DEGONG mashing system
2. The wort is cooled to before inoculation. The types of bacteria that are susceptible to infection are: coliform, wild yeast, lactobacillus, micrococcus, bacillus subtilis, mold, actinomycetes, flavobacterium mutans, etc. These bacteria can still grow at 40°C, and unclean water should be prevented from being mixed into the wort, which can multiply millions of times within 7 hours; yeast contamination, can compete with yeast for reproduction, and stop growing before fermentation is completed; often lurking in the gap , thread and litter, the wort is brought in through the flow, and some are brought in by the reusable yeast; Acetobacter and Lactobacillus are contaminated in the wort, and the growth is slow, because the thin plate system has dead corners or poor hygiene and sterilization. Thorough; sterile air system infection, etc.
3. In the fermentation stage, the types of bacteria that are susceptible to infection: Lactobacillus, Acetobacter, wild yeast, football bacteria, Flavobacterium mutans. These bacteria are generally caused by incomplete system hygiene and sterilization; yeast inoculation process, etc., yeast contamination, and a large number of growth and reproduction during fermentation. Open fermentation is conducive to the growth of acetic acid bacteria, and closed fermentation is conducive to the growth of lactic acid bacteria.
4. In the beer storage stage, the types of bacteria that are susceptible to contamination: Acetobacter, Lactobacillus, Zymomonas, and coliform bacteria, which multiply rapidly when there is air in the upper part of the beer or the wine, generally because the fermenter is not cleaned and sterilized completely; The wine storage tank, sake tank and wine filter system are not completely sterilized when drinking.
5. In the packaging stage, the types of bacteria that are susceptible to contamination: Acetobacter, Lactobacillus, Football bacteria, Zymomonas, Coliforms, mold, generally because of the wine supply system for packaging, the wine tank of the filling machine, empty bottles, empty bottles, etc. barrels, etc., are contaminated during the packaging process.