Besides exploding cans, I would say that this topic—a pair of the sneakiest, most pernicious bacteria that can be found in a brewery—has given me the most sleepless nights during my career of quality testing in the industry. The resurgence of light lagers and pilsners in the craft sector is pretty recent, so many of us, as craft brewers, may not even be aware of these especially harmful bacteria, which have usually only been a problem for macrobreweries.
Megasphaera and Pectinatus are two genera of gram-negative bacteria (think E. coli) that thrive in low-oxygen environments. Here, we’ll consider the detrimental effects of these bacteria, where they can be found in the brewing environment, and what can be done to prevent them from infecting your beer—so, hopefully, they don’t keep you up at night, too.