AN UPDATE OF ZINC ION AS AN EFFECTOR OF FLOCCULATION IN BREWER'S YEAST STRAINS

Abstract

Zn++ ion was observed to be a strong effector of the flocculation—deflocculation process in an in vitro system for strains of Saccharomyces cerevisiae at ion concentration ranges that are normal in conventional substrates, such as wort. All strains of Saccharomyces uvarum (carlsbergensis) examined in this study did not exhibit any flocculation response to Zn++ ion. This test could be employed to distinguish between ale and lager flocculating yeast strains. 1990 The Institute of Brewing & Distilling