Table of Contents
Enhancing Flavour Stability in Beer Using Biological Scavengers - Part 2: Screening of Yeasts
H. Ahrens, J. Schröpfer, L. Stumpf, R. Pahl, J. Brauer and S. Schildbach
The diffusion of oxygen into the bottles and the subsequent oxidation of beer components is the main cause for deteriorating flavour during storage, limiting the shelf life of the beer. Unfiltered beers coming into vogue in recent years still contain active yeasts. Active yeasts are known to be capable to metabolize oxygen and subsequently to act as biological oxygen scavengers, which offers the opportunity of enhancing the shelf life of beer in a natural way. Yeasts from a number of traditional, unfiltered beers were isolated. A total number of nine yeasts from these beers and additionally three standard yeasts from VLB (Versuchs- und Lehranstalt f?r Brauerei in Berlin (Research and Teaching Institute for Brewing in Berlin, Germany)) yeast strain collection were examined for their ability of scavenging the oxygen in beer, taking into account the impact on sensorics as well as on basic analytics in beer. The yeasts were rated for their ability to be used as biological scavengers following a test protocol recently described in a previous paper. Especially one selected yeast (yeast I (PA-2)) showed very encouraging results.
Descriptors: biological scavengers, flavour stability, beer, bottle fermentation
BrewingScience, 71 (March/April 2018), pp. 24-30
