High hydrostatic pressure treatments for beer stabilization

Crude cloudy beers from a small-scale brewery were treated with high hydrostatic pressure (HHP-600 MPa, 5 min) or heat pasteurized (60 degreesC, 10 min). The treatments did not affect pH, ethanol, extract, bitterness, or phenolics in comparison with untreated beers; HHP beers retained permanent haze, similar to untreated samples. Heat pasteurized beer resulted in a more rapid increase of the a* (red) and a slower decrease of the b* (yellow) color parameters than in HHP samples. The microbiological stability of HHP beers was comparable with heat-treated beers, and the development of yeast and lactic acid bacteria was inhibited for 49 d of storage.