MBAA TQ https://doi.org/10.1094/TQ-58-2-0426-01 | VIEW ARTICLE
William Maca. HWM Yeast Solutions LLC, Grafton, WI, U.S.A.
This paper is based on a presentation made at the MBAA meeting in Calgary, Canada, in 2019. The purpose of that presentation was to share my experiences with fermentation issues over 8 years as a consultant for both large and craft brewers. During these consultations, there appeared to be knowledge gaps that ranged from not understanding what the fermentation metrics were telling brewers, to some breweries not making any measurements in the fermentation process at all. This paper was written to provide guidance to brewers with a with a back-to-basics approach to fermentation monitoring. The discussion touches on fermentation process parameters, the definitions of viability and vitality and how to measure them, and how to use these measurements to determine the suitability of harvested yeast for repitching. Fermentation performance is the best judge of yeast vitality, but on the other hand, no single vitality test method predicts fermentation performance very well in practice. These vitality tests typically suffer from being too complex, too expensive, or taking too long for needed results. The best way to achieve consistent fermentations in any brewery is to establish standard operating procedures, which have at their core the implementation of best practices for propagation, cropping, collection, storage, and pitching, with special consideration given to the specific strain(s) being used.