Premature yeast flocculation factors from barley malt present in both malt husk and the non-husk part

Abstract

In the present study, small-scale fermentations of seven malts from different maltsters in China were used to monitor their premature yeast flocculation (PYF) potential. Husk exchange was applied between PYF negative malt (PYF-) and PYF positive malt (PYF+) to investigate the PYF factors potentially present in the husk. The results showed that PYF factors were present in both malt husk and the non-husk part. The two factors showed various ratios among different PYF+ malts, and either of them could induce PYF if it reached the threshold. Moreover, the major antimicrobial substances damaging the yeast cells were in the non-husk part. © 2014 The Institute of Brewing & Distilling.