Methods of Microbiological Quality Control
Due to the low pH value, the high CO2 and alcohol content and the bitter substances it contains, beer does not generally offer good living conditions for most bacteria and is therefore not very susceptible to contamination. Nevertheless, some beer spoilers, including Lactobacillus spp., Pediococcus spp., Pectinatus spp. and Megasphaera spp. have adapted in such a way that they can grow undisturbed even under these conditions. These germs do not usually pose a health risk to humans, but can cause sensory defects and thus lead to the loss of entire batches and considerable damage to the company's image. If contamination is suspected or has already occurred, the entire process chain must be examined as quickly as possible. The analysis process can be extremely time-consuming and can even lead to production being halted for a certain period of time. The economic losses in this case are enormous, which is why reliable and rapid microbiological quality control is essential for the brewing industry.
| The cultural detection of microorganisms based on culture media is simple and inexpensive, but often unspecific and time-consuming. In addition, up to 99 % of all bacteria cannot be cultivated at all. | Quality control with VIT® gene probe technology: With VIT®, beer spoilage bacteria can be detected quickly and specifically, regardless of their cultivability. Inhibitors in the sample material do not play a role. The bacterial cells remain intact during the analysis, which enables clear assignment of the signals and reliable quantification of the cells. Both finished products and samples from all stages of the brewing process, including yeast propagation, can be analyzed. | ||
| Molecular biological methods (e.g. PCR) are fast, but the presence of inhibitors in the sample material and the detection of dead cells often lead to false-negative or false-positive results. |
The Advantages at a Glance
Our decades of experience in detecting bacteria in beer and beer-based mixed drinks make us the ideal partner in this field. We have developed our test systems for the brewing industry in close cooperation with the renowned Chair of Brewing and Beverage Technology (Technical University of Munich, Weihenstephan, Prof. Back). Satisfied customers all over the world trust our technology.
specific: precise identification of bacteria regardless of their morphology or cultivability
fast: low detection limit and easy handling
only live bacteria: dead bacteria are not detected
robust: no use of enzymes that are susceptible to interference
universal: can be used throughout the entire production chain (raw materials, in-process control and end product control, as well as yeast propagation)
Stage-by-Stage Control
If contamination is suspected or if the end product has already been contaminated, the entire process chain must be checked as quickly as possible. With VIT®, all stages of the brewing process can be examined quickly and specifically to find the source of contamination.
Yeast Inbreeding
Contamination of the yeast or refeeding yeast can lead to the entire production batch being discarded. Thanks to the fast and highly specific VIT® results, the yeast can be released quickly and thus transformed from a risk factor into a safety factor in the production process.
Final Product Quality Control
Before a batch is released, the final product must be tested for beer spoilage organisms. With VIT® this can be done quickly, specifically and easily. The result is a clear release decision.
Quality Assurance at the Highest Level
Have you found microbial contamination in your sample and want to find out about the potential damage to production? We offer a comprehensive service portfolio and a wide range of test kits for fast and specific quality assurance of the entire production chain - from the raw material to the end product.
Services
Have you found microbial contamination in your sample and want to find out about the potential damage to production? We offer a comprehensive service portfolio and a wide range of test kits for fast and specific quality assurance of the entire production chain - from the raw material to the end product.
Recommended VIT® Test Kits
VIT® Beer plus L. brevis
Test kit for rapid analysis of all beer spoiling lactic acid bacteria and especially Lactobacillus brevis.
VIT® Beer Megasphaera/Pectinatus
Do you suspect beer spoilage? This test kit quickly analyzes bacteria of the genus Pectinatus and Megasphaera cerevisiae.
VIT® Beer Screening
Unwanted microorganisms in beer? This test kit specifically identifies all beer spoilage organisms from the genera Lactobacillus and Pediococcus.
VIT® Spoilage Yeasts
Test kit for the rapid analysis of live obligate and potentially fermentable yeasts in still and carbonated beverages.
Lactic Acid Bacteria
Although many different families, genera and species of lactic acid bacteria exist, only a small fraction of their representatives are considered harmful to beer. These include: Lactobacillus brevis, L. backi, L. collinoides, L. plantarum, L. rossiae, L. coryniformis, L. buchneri, L. harbinensis, L. paucivorans, L. acetotolerans, L. casei, L. lindneri, Pediococcus claussenii, P. inopinatus and P. damnosus. Contamination with lactobacilli causes a sour and with pediococci a sweetish-caramel, buttery taste of the end product. They also lead to turbidity and / or sediment.
Harmful Yeasts
A distinction must be made between obligate and potentially fermentable yeasts. The obligate fermentable yeasts, also known as spoilage yeasts, includingSaccharomyces cerevisiae, S. bayanus, S. exiguus, Brettanomyces spp., Zygosaccharomyces spp. and Schizosaccharomyces spp. can cause overfermentation in the end product. In the worst case, this leads to the bursting of the beverage containers and thus poses a considerable risk to the consumer. In addition, these yeast species, in combination with other microorganisms such as acetic or lactic acid bacteria, are one of the causes of creamy skin.
Megasphaera spp. and Pectinatus spp.
Beer contaminated with Pectinatus spp. or Megasphaera spp. is characterized by an unpleasant, foul odour reminiscent of hydrogen sulphide. In addition, these germs lead to strong turbidity in the end product. Both beer spoilers are strictly anaerobic and are typical examples of secondary contaminants. Contamination of the end product is usually caused by inadequate cleaning and disinfection of the bottling process.
Hygiene-Relevant Germs
If contamination with pathogenic germs occurs, the cause is usually a lack of hygiene in the dispensing system or the bar and not in the production process or the end product. Due to the low pH value, the high CO2 and alcohol content and the bitter substances contained, harmful germs rarely survive in beer. However, the brewing water is subject to the German Drinking Water Ordinance and is tested several times a year for bacterial(Escherichia coli, Salmonella, Legionella etc.) or chemical contamination.
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