Brettanomyces bruxellensis (Brett) is a yeast which can cause significant spoilage in beverages through the production of volatile phenol compounds. These compounds are associated with undesirable sensory characters such as ‘Band-Aid’, ‘medicinal’, ‘horsy’ and ‘barnyard’.
Beverage producers should be aware of the prevalence of Brett and have a prevention strategy in place, even if spoilage problems have not been experienced in the past. Where a Brettanomyces infection is suspected or confirmed, there are two tests available from Affinity Labs to positively detect and quantify the presence of viable cells, even before the concentration of volatiles has risen above the sensory threshold.
Selective plating is considered the gold standard in Brett detection and can be performed on almost all beverage types. Although it has a ten-day turnaround time for analysis, it is highly sensitive, detecting a single cell per 50 mL sample, and provides a quantitative result. This method is selective for Brett, but may detect other microorganisms, so sometimes additional confirmatory testing is required. This is done through either microorganism ID or one of the nucleic acid-based methods below. Selective plating is ideal for regular monitoring for Brett or where turnaround time is not critical.
Veriflow is a PCR method that specifically targets Brettanomyces bruxellensis DNA. It is fast, highly sensitive and able to detect 10 cells per 1 mL sample, but cannot distinguish between dead and viable cells. This method therefore cannot be relied upon to determine if a known infection has been successfully treated. The Veriflow method is best used to confirm a positive selective plating result where the quantitative level of contamination is low, or in cases where Brett contamination is suspected, and a quick result is needed.
Click here for more information on the Brettanomyces tests offered by Affinity Labs.
