Influence of (+)-catechin and ferulic acid on formation of beer haze and their removal through different polyvinylpolypyrollidone-types

The influence of (+)-catechin and ferulic acid on the formation of haze was investigated. Both phenolic compounds were added in different concentrations to beer before ageing through a force test. The removal of these compounds was observed by measuring the difference before and after forcing the beer. (+)-Catechin and ferulic acid showed haze-decreasing as well as haze-increasing properties. The removal of (+)-catechin and ferulic acid from beer through three types of polyvinylpolypyrollidone (PVPP) at several concentrations was investigated. The removal of (+)-catechin and ferulic acid by PVPP-filtration was totally different. The removal of (+)-catechin can be used as a basis to calculate the doses for a desired stability, whereas ferulic acid is removed in irregular amounts.