Microbes in the Beer Quality Report 2017

You may or may not be a beer drinker or know much about the brewing industry as a whole but regardless of where you fall on those spectrums of familiarity, you’ll likely be surprised by the role bacteria were found to play in hurting the quality of beer in the United Kingdom, as reported in the Beer Quality Report 2017. Published by Cask Marque, a beer quality watchdog in the UK, the Beer Quality Report shares the results of research done in 22,000 pubs across the United Kingdom. Perhaps of note to the microbiology community is the report’s section on line cleaning.


As mundane as line cleaning sounds, the report projects that the economic value lost for a typical pub due to bacteria and yeast-laden draught beer lines is around $40,000 – no small sum for your average pub. What may be more disturbing to most beer drinkers is the finding that one in three pints served in the UK is drawn through unclean beer lines. That means that a third of the lines were found to have yeast and bacterial buildup to the extent that it hurt beer quality. Besides being unnerving, it’s worth noting that bacteria tend to spoil the aroma and flavor of beer, which ruins the experience for consumers, and is just bad for business.


Another interesting finding from the report is the breakdown of unclean beer lines by type of beer. For instance, cider lines were found to be the dirtiest in the UK on average, with 44 percent of inspected lines determined to be unclean. When beer type was combined with location, it was found that 53 percent of cider lines in Wales were determined to be unclean. The next most likely beer type to be drawn through dirty lines were stout beers, as the report found that 36 percent of those lines were found to be unclean. Premium and standard lagers were the next most likely lines to be unclean, with 35 percent and 36 percent of those lines found to be dirty, respectively.


Fortunately, beer is generally considered inhospitable to the majority of the microorganisms, as the low pH and ethanol concentration effectively limit bacterial growth. As a result, there are only a few known bacterial strains that are able to grow under these conditions. Nonetheless, these types of reports illustrate the importance of understanding microbes and their potential to affect every aspect of daily life. As the Beer Quality Report 2017 shows, microbes even play a significant role in economic success and consumer satisfaction. Not bad for being microscopic.