The influence of LOX-less barley malt on the flavour stability of wort and beer

Abstract

The aim of this study was to investigate the influence of lipoxygenase-less (LOX-less) barley malt on the quality of wort and beer, with the main focus on beer flavour stability. In the current study, pilot-scale (1000 L) brewing trials were conducted with a control barley malt AC Metcalfe and a LOX-less barley malt, PolarStar. The results clearly indicated that the LOX-less barley malt showed less nonenal potential than the control, although LOX activities in both barley malts were relatively low. The beer brewed from the LOX-less barley malt contained much lower concentrations of trans-2-nonenal (T2N) and gamma-nonalactone, especially after the (forced or natural) aging of the beer, compared with the beer brewed under the same conditions using the control malt. The sensory panel evaluation indicated similar results in the general flavour profile. The freshness scores of beer brewed from the LOX-less malt were higher than those from the control malt, and this was more pronounced after forced aging. In addition, the beer brewed from LOX-less malt had a much better foam stability, almost 30 s (NIBEM test). These results confirm that the use of the LOX-less barley malt was beneficial to beer flavour stability and foam stability. © 2014 The Institute of Brewing & Distilling.