Brewers are increasingly aware of the importance of yeast health and need appropriate methods to measure its vitality. Many of the current methods are time consuming, expensive or impractical at an industrial scale. Here, the measurement of CO₂ production using the ANKOM RF Gas Production Measurement System was optimised. Using response surface methodology, the optimal temperature, yeast biomass and media composition were established. The performance of the method was assessed by measuring the vitality of yeast from laboratory (20 L) and brewery (400‐600 hL) fermentations. The drop in pH in early fermentation, diacetyl reduction and fermentation rate were correlated to measurement of yeast vitality. It was shown that the method can be used to assess yeast health and to predict its performance in brewery fermentation. The measurement time was 20 minutes and a minimum vitality of approximately 200 mbar was found to be sufficient for brewery fermentations. The method can be used to optimise yeast propagation processes or to determine the optimal harvesting/cropping time to improve yeast quality, fermentation consistency and beer quality together with reducing cycle time and time in fermenter. © 2020 The Institute of Brewing & Distilling

中文翻译：

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优化酵母活力测量以更好地预测发酵性能

酿酒商越来越意识到酵母健康的重要性，并需要适当的方法来衡量其生命力。当前许多方法在工业规模上是耗时的，昂贵的或不切实际的。在这里，CO ₂的测量优化了使用ANKOM射频气体生产测量系统的生产。使用响应面方法，确定了最佳温度，酵母生物量和培养基组成。通过测量实验室（20 L）和啤酒厂（400-600 hL）发酵酵母的活力来评估该方法的性能。早期发酵中pH的下降，二乙酰基还原和发酵速率与酵母活力的测定相关。结果表明，该方法可用于评估酵母健康状况并预测其在啤酒发酵中的性能。测量时间为20分钟，并且发现大约200 mbar的最小活力足以满足啤酒厂的发酵需求。该方法可用于优化酵母的繁殖过程或确定最佳的收割/播种时间，以提高酵母质量，发酵一致性和啤酒质量，同时减少发酵罐中的循环时间和时间。©2020酿酒与蒸馏研究所