Conventional and alternative principles for stabilization of protein and polyphenol fractions in beer

Beer haze is primarily formed through complexation of protein and polyphenolic beer ingredients. The problem of reducing susceptibility of beer haze formation can be done either by lowering protein and/or polyphenol levels, or by minimizing the molecular size of protein/polyphenols. In experimental part of this work the shelf life of unstabilized beer is being compared with beer stabilized with various standard products, such as PVPP and silica gel. Furthermore, the trials have been made to prove the functionality of a new product consisting of carrageenan and cross-linked PVPP. The method used to determine shelf life was haze forcing test (0/60°C). Extract, alcohol, bitterness, foam, haze, color and pH were also monitored. The test results showed expectedly that combined treatment of beer ensures the highest level of product stability. Through selective stripping of polyphenols and protein fractions it is possible to improve shelf life of beer to a significant extent