Beer Spoilage Organisms
(book excerpts)Despite beer’s inherent stability, a limited number of microbes can grow that are collectively known as “beer spoilers” which include bacteria, yeasts, and molds. Beer-spoilage microbes include bacteria belonging to genera of Lactobacillus, Pediococcus, Megasphaera, and Pectinatus. In addition, the most common genera of yeast that can spoil beer include Saccharomyces and Brettanomyces species. 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, excessive acidity, gushing, and reduced yeast crops. Aspergillus niger, also called “black mold,” is a fungus common in breweries.
Click on the following topics for more information on beer spoilage organisms.
Topics Within This Chapter:
- Major Beer Spoilers
- Spoilage by Bacteria
- Gram-Positive Bacteria
- Gram-Negative Bacteria
- Spoilage by Wild Yeast
- Saccharomyces spp.
- Non-Saccharomyces spp.
- Spoilage by Molds
- Monitoring Microbes
- Microscopic Observation
- Microbial Culture Plating
- Adenosine Triphosphate (ATP) Bioluminescence
- Polymerase Chain Reaction (PCR)
