A study on kinetics of beer ageing and development of methods for predicting the time to detection of flavour changes in beer

Abstract

The kinetics of beer ageing were studied based on the development of beer stale flavour with storage time. Results showed that the beer ageing rates at 50 and 60°C were 30.0 and 56 times as fast as those at room temperature, respectively. Based on these findings, two methods (method A and B) for predicting the 'time to detection of flavour change' (TDFC) of beer were developed. TDFC is the beer shelf-life in terms of flavour stability. In method A, beers were stored in a 50°C water bath and the intensity of beer ageing was scored daily. Thus, the range of TDFC of the beer was acquired according to the maximum number of days within which the intensity of beer ageing was ≤2 and the minimum number of days within which the intensity of beer ageing was >2. In method B, the 2-thiobarbituric acid (TBA) values of a beer were determined before and after 1day of storage in a 50°C water bath, and the TDFC of the beer was calculated using the equation: TDFCdays=5.19ΔTBAwhere ΔTBA is the increment of TBA value during 1day of storage at 50°C. Both methods were simple, rapid and accurate.