Hygienic Hazards In Beer Production

In the beer brewing process, it is inevitable that heterogeneous microorganisms are invaded. The growth and reproduction of these microorganisms use wort (very good culture medium) or the nutrients in beer, resulting in difficulties or abnormalities in subsequent production, resulting in precipitation and precipitation of the finished beer. The turbidity and even its metabolites cause the beer flavor and taste to change.

PART1 The strains of contamination in different stages of the beer production process are different

Saccharification stage

Types of susceptible bacteria:

Lactobacillus thermophilus

Illustrate:

At the beginning of saccharification, when the temperature of the mash is less than or equal to 50°C, it is easy to stain, but it is beneficial to lower the pH of the mash; above 50°C, lactobacillus is not easy to grow, so it is not easy to be infected.

Wort cooling to inoculation process

Types of susceptible bacteria:

① Coliform

②Wild Yeast

③Acetobacter, Lactobacillus

Micrococcus, Bacillus subtilis, mold, actinomycete, Flavobacterium mutans, etc.

Illustrate:

 ① The coliform bacteria can still grow at 40°C. It is necessary to prevent dirty water from being mixed into the wort. The bacteria multiply very fast and can multiply millions of times within 7 hours. A small amount of bacteria can cause serious damage and it is not easy To eliminate, intermittent wort used in continuous fermentation should pay more attention to this bacterial contamination.

 ②Wild yeast often lurks in the gaps, threads, and bedding of the pipeline. When the wort flows through the pipeline, it is easy to bring in; it may also be brought into the reusable seed yeast. The seed yeast is contaminated and can compete with the yeast to reproduce, and the fermentation is completed. Stop growing before.

 ④ Acetobacter and Lactobacillus are contaminated in the wort, grow slowly, the thin plate system is dead or poor, and the sterilization is not complete; the aseptic wind system is infected.

Fermentation stage

Types of susceptible bacteria:

① Flavobacterium mutans

②Pasteuric acid bacteria, acetic acid bacteria

③ Coliform

④Wild Yeast

Illustrate:

①Flaverobacterium mutans is mainly contaminated during yeast inoculation. In general, the promoters in the yeast are infected with this bacteria. This bacteria can make the yeast compete for reproduction and stop growing before the fermentation is completed.

②Pasteurian lactic acid bacteria and acetic acid bacteria often have this bacteria in the inoculated yeast. The two bacteria can grow during fermentation. Open fermentation is beneficial to the growth of acetic acid bacteria, and closed fermentation is beneficial to the growth of lactic acid bacteria.

③ Coliform flora, which is contained in yeast.

④ The main source of contamination of wild yeast is seed yeast. Although the pollution rate is very low when planted, the wild yeast has a higher pollution rate in the recovered yeast after fermentation.

Wine storage stage

Types of susceptible bacteria:

①Acetobacter

② Lactobacillus

③Zymomonas

④ Coliform

Illustrate:

Fermentation tanks are not thoroughly cleaned and sterilized; wine storage tanks, sake tanks and wine filter systems are not fully sterilized when serving wine;

    ① Breed faster when drinking or there is air in the upper part of the wine

    ②Growing under anaerobic condition

    ③It develops rapidly under anaerobic condition and is rarely found

Packaging stage

Types of susceptible bacteria:

Acetobacter

Lactobacillus

Football fungus

Zymomonas

Coliform

Mold

Illustrate:

For packaging wine delivery systems, filling machine wine tanks, empty bottles, empty barrels, etc., heavy pollution during the packaging process.

PART2 Two categories of microorganisms

Not all microorganisms entering the beer brewing process are harmful bacteria of beer. According to their hazards to beer, these microorganisms can be divided into two categories

1. Harmless symbiotic bacteria

Harmless symbiotic bacteria refer to mold spores and many aerobic bacteria. They cannot grow in beer, and even the special environment of beer can suffocate them; but if these microorganisms exist, it also means that harmful microorganisms may also exist.

The so-called (relative) microorganisms that are harmless to beer-refer to the micrococcus and micrococcus that cannot reproduce in beer brewing.

2. Harmful bacteria

Harmful bacteria refer to human pathogenic bacteria (such as coliform bacteria), or microorganisms that grow and multiply under specific conditions and cause abnormal beer production process, or make beer rancid, tasteless, viscous, sedimentation, or turbidity;

The species belonging to harmful bacteria include: wild yeast, Lactobacillus, Streptococcus, Pectobacterium, Megacoccus, Intestinal bacteria, etc.