EFFECT OF STORAGE ON HOP EXTRACTS

Representative commercial hop extracts suffered no appreciable loss either of α‐ or β‐acids or of bittering value when kept for 2 to 21 months in closed containers. Though there was loss of α‐ and β‐acids on prolonged exposure of the extracts to air, it did not lead to a corresponding loss of bittering value. Of a range of commercial isomerized extracts, most proved satsifactorily stable on storage. However, when large losses of iso‐α‐acids did occur they were accompanied by corresponding reductions in bittering value. With reference to bittering compounds, there appeared to be no significant differences in the storage stability of beers bittered using hops or extracts of various types. 1969 The Institute of Brewing & Distilling