Does Generation Number Matter? The Impact of Repitching on Wort Utilization

摘要

Serial repitching is an accepted practice in brewing. The number of completed fermentations (generation number) is the metric applied to brewing yeast fitness for fermentation. Despite this, fermentations that use freshly propagated (generation 0) yeast are deemed to be inefficient when compared to yeast that has been repitched one or more times. The aim of this study was to investigate the impact of yeast generation number (equating to the number of fermentations completed) on wort utilization and fermentation progression. Wort composition and pH downshift were used to assess "fitness to ferment" of yeast generations within laboratory scale fermentations. Differences in pH, FAN, and amino acid assimilation were observed.