Prediction of the Formation of Frozen Beer Precipitates

Abstract

The presence of frozen beer precipitates in packaged beer is a major consumer complaint, especially during cold winters. Therefore, it is important for brewers to predict the frozen stability of finished beer. The frozen stability of a packaged beer cannot be predicted by methods used to predict colloidal stability, such as the forcing test or alcohol-chilling test. To evaluate the frozen stability of canned beer, the freeze and thaw (F&T) cycle test was developed. We reproduced the change in outdoor temperature over 24 hr, which ranged from −2 to −12°C during winter, in a programmable incubator and measured the amount of precipitates formed. There was a large variation in the amount of frozen beer precipitates (F&T values) formed in commercial beers. Using this test, we found that two factors affect the frozen stability of beer. One factor is the composition of beer. The F&T value usually increased with an increase in the β-glucan content of beer. However, beer components such as α-glucan also greatly affected frozen stability. The other major factor affecting frozen stability is the practical freezing point of a packaged beer, which ranged from −7.1 to 13.8°C. We can determine the frozen stability of beer from these two factors and improve the visual quality of beer.