A Challenge in the Study of Flavour Instability

Abstract

There has been a substantial focus over many years on the potential impact of upstream ingress of oxygen on the ensuing flavour stability of the beer produced from the wort. There have been conflicting conclusions, ranging from those who believe the effect is substantial to those who believe that upstream oxidative events are of little significance for the shelf life of beer. Here we have made a theoretical analysis of the likeliest destination for oxygen in mashes, focusing on the kinetics of enzymic and non-enzymic reactions. We suggest that a focus on kinetic modelling of events throughout the process should be taken by researchers, recognizing that it is the rate with which staling reactions occurs that is of most significance as it speaks to the rate at which flavour change is observed in beer, the latter being of more significance than the extent to which it occurs.