By Michael St Michael
2 minute read
Who doesn’t like beer? Ok, we know some taste- and fun challenged people who do not. Non-alcoholic beer, however, is a tough sell with me. It just got tougher for the UK drinking public, too. There, Guinness’ parent company, Diageo (who also makes Smirnoff vodka, Johnnie Walker whisky and Captain Morgan rum) said today that it will yank its new alcohol-free Guiness 0.0 from the UK market after finding evidence of “microbiological contamination”.
In brewing, microbiological contamination can take many forms and happen during any portion of the typical eight-stage brewing process. Dirty equipment is often to blame, but in some cases bacteria in mash or other ingredients can infect the product. Fungus can invade stocks of barley if they grains are subject to certain environmental conditions, such as poor storage. Faulty yeast can also lead to spoilage. Since a large brewery like Guinness’ famous St James’s Gate brewery in Dublin is unlikely to employ the process of simply introducing yeast from one brewed batch to the next (something called “backslopping”), yeast quality control is probably not to blame in the Guinness 0.0 case.
Overgrowth of undesirable bacteria can also take place during the mashing of malt. During mashing, the malt is usually acidified using lactic acid bacteria to enhance the flavor and color of the beer. However, improper mashing can lead to the growth of Clostridium bacteria, which impart a cheesy flavor to the final product.
For true beer nerds, check out the work of Nicholas Bokulich and Charles Bamforth who treat the microbiology of brewing – and all the ways it can go wrong.
Perhaps this biggest question in all of this is why people drink non-alcoholic beers at all.