Beer Spoilage Organisms(book excerpts)
Microbial contamination can originate from a variety of sources in the brewing process. Raw materials, air, brewing water, additives, and even pitching yeast can act as a constant supply of contaminants. Residues remaining in brewhouse tanks, pipelines, valves, heat exchangers, and packaging equipment harbor microorganisms too that represent a potential source of recontamination. Some of the effects of contamination range from comparatively minor changes in beer flavor and fermentation performance to gross flavor and aroma defects, turbidity problems, abnormal attenuation rates, and reduced yeast crops.
A number of microorganisms have been reported to be beer spoilage microorganisms, among which bacteria, as well as so-called wild yeast and molds.
Click on the following topics for more information on beer spoilage organisms.
Topics Within This Chapter:
- Introduction to Beer Spoilage Organisms
- Microorganisms — Brewing Stages
- Gram-Positive Bacteria
- Lactobacillus spp.
- Pediococcus spp.
- Gram-Negative Bacteria
- Acetic Acid Bacteria
- Zymomonas spp.
- Pectinatus spp.
- Enterobacteriaceae spp.
- Wild Yeasts
- Saccharomyces spp.
- Non-Saccharomyces spp.
- Brettanomyces spp.
- Torulopsis, Pichia, and Candida spp.
- Microbiological Quality Assurance