The role of a microbiologist is becoming increasingly important in the production of high-quality wine and beer. Their primary role is to ensure that no unsafe microbes are introduced into the beverage production process and that the drink quality is not compromised.

PCR and ATP detection technologies prevent huge batch losses

Real-time monitoring technologies like rapid polymerase chain reaction (PCR) and adenosine triphosphate (ATP) detection offer new critical control points and more monitoring as additional steps to prevent huge batch losses due to microbial contamination during the brewing and winemaking processes. Due to the high alcohol content of these beverages, pathogen contamination is greatly reduced because they cannot thrive in alcohol. They are also kept at bay due to the anaerobic packaging these drinks come in, like vacuum packs and kegs.

In some products, a manufacturer may choose to produce drinks with lower alcohol content using certain strains of yeast. Developing low-alcohol beers, especially ones that are between one to three percent, is risky due to a higher chance for pathogen or unwanted microbes to grow. Often, brewers choose to stay above the three percent alcohol level. The quality of wine and beer may be affected by contaminants like lactic acid bacteria (LAB) and brettanomyces. The presence of LAB can inhibit fermentation by the yeast and can yield hydrogen sulphide, easily identified by its burnt rubber smell. Other contaminants include acetobacter and cronobacter, the former producing acetic acid (vinegar) and possible acetaldehyde, which is difficult to remove and detrimental to the batch.

Culture-based and Molecular methods

Culture-based: dehydrated agar-plates for lactobacillus and pediococous are cost-effective and can give you a total viable count. They come with membrane filters that can be placed onto the agar after membrane filtration. Molecular methods/PCR: as it is the genes horA and horC that provide hop-resistance to bacteria, these genes are common amongst the hop-tolerant spoilage bacteria. The PCR kits that are available in the market target these genes.