Proanthocyanidin-free barley prevents the formation of beer haze.

von Wettstein, D., Jende-Strid, B., Ahrenst-Larsen, B. and Erdal, K.

Abstract
Proanthocyanidins (anthocyanogens) are the most potent of the polyphenols that precipitate proteins to give chill and permanent haze in beer. Some 50 proanthocyanidin free mutants have been isolated in different barley varieties by treatment with mutagenic agents. The recessive mutant ant 13-13 from Foma has been grown for malting and brewing trials at pilot and production scale. The malt, wort and beer produced was free from catechins and proanthocyanidins and no detrimental effects were observed. The beer was of excellent haze stability without any stabilizing treatment. In brews containing mixtures of ant 13, normal malt and maize grits the proportion of the mutant determined the proanthocyanidin content of the beer and its haze stability. Blending ant 13 beer with unstabilized normal beer improved its haze stability. Ant 13 yielded 25% less than its parent variety Foma because of its high susceptibility to powdery mildew but it is likely that high yielding, disease resistant, proanthocyanidin free varieties can be developed by recombination and mutation breeding.
Keywords: barley beer catechin haze mutant proanthocyanidin