Optimised beer pasteurisation
Our recent research shows that effective pasteurisation for selected organisms in beer can be achieved at significantly lower PU values than those currently recommended. Optimising pasteurisation for different beer styles and microorganisms is likely to result in reduced costs, lower energy use and decreased water waste for breweries. It also has the potential to improve quality, as over-processing of beverages may result in damage to aroma and flavour compounds.
The viable cell concentration in ale and stout beers was reduced to achieve ‘commercial sterility’ at significantly lower PU values than those recommended by the EBC (European Brewery Convention) Manual of Good Practice. We achieved an 8.7 log reduction in the vegetative cell numbers of the selected organisms at just 1.59 PU (pasteurisation units). The EBC recommends between 15-25 PU for light and 20-35 PU for dark beers.
Further studies are required to demonstrate the optimal level of pasteurisation for spore-forming bacteria and yeast ascospores. The research has been published in the Journal of the Institute of Brewing.