Several Processes Easily Infected with Bacteria in Beer Production

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

Beer Saccharification stage:

Susceptible bacteria species: thermophilic Lactobacillus

Note: At the beginning of saccharification, when the temperature of the mash 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, the lactobacillus is not easy to grow.

The wort is cooled to before inoculation: 

Susceptible bacteria species: coliform, wild yeast, lactobacillus, micrococcus, bacillus subtilis, mold, actinomycetes, Flavobacterium mutans, etc.

Note:

• It can still grow at 40°C, and it should be prevented that unclean water is mixed into the wort, and it can multiply millions of times within 7 hours;

• Often lurking in gaps, threads, and litter, the wort is brought in through the flow, and it is also brought in from the repeatedly used yeast.

• Contaminated by yeast, it can compete with yeast for reproduction and stop growing before fermentation is complete.

• Acetobacter and Lactobacillus are polluted in wort and grow slowly.

Dead corners of the thin plate system or poor hygiene and incomplete sterilization; infection of the sterile air system.

Fermentation stage:

Susceptible bacteria species: Lactobacillus, Acetobacter, wild yeast, football bacteria, Flavobacterium mutans.

Description: common system hygiene brushing, sterilization is not thorough; yeast inoculation process, etc.;

The yeast is polluted, and it grows and reproduces in large quantities 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.

Beer storage stage:

Susceptible bacteria species: Acetobacter, Lactobacillus, Zymomonas, Coliform

Description: The fermentation tank is not cleaned and sterilized completely; the wine storage tank, brite tank and beer filter system are not completely sterilized when serving beer;

• It breeds quickly when there is air in the upper part of the beer or wine

• Grow under anaerobic conditions

• Rapid development under anaerobic conditions, rarely found

Beer Packaging stage:

Susceptible bacteria species: Acetobacter, Lactobacillus, Football bacteria, Zymomonas, Coliform, mold

Description: For the packaging and conveying system, the beer tank of the filling machine, the empty bottle, the empty barrel, etc., it is heavily polluted during the packaging process.

Not all microorganisms that enter the beer brewing process are harmful bacteria of beer. According to their harm to beer, these microorganisms can be divided into two categories: harmless symbiotic bacteria/harmful bacteria.

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

The so-called harmless to beer (relatively) microorganisms – refers to the microorganisms that cannot be reproduced in beer brewing, such as some good spore bacteria that do not cause beer to become turbid and turbid.

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

The species that belong to harmful bacteria are: wild yeast, Lactobacillus, Streptococcus, Pectinobacter, Megacoccus, Enterobacteriaceae, etc…