Dry yeast repitching: flavor and performance over multiple generations

Dried brewing yeast has earned an important place in modern breweries, thanks to its ease of use, cost savings, and long shelf life. For many years, however, there has been an open question: Can dried yeast perform just as reliably as liquid yeast when repitched across multiple generations? To address this, our team at Oregon State University compared liquid-propagated and dried forms of the same lager strain, LalBrew Diamond™, focusing on fermentation performance, flavor outcomes, and yeast stability through four successive fermentations.

Experimental design

The trial involved 150-liter brews made from a wort of 80 percent pale lager malt and 20 percent light Munich malt, targeting a final alcohol content of 5% ABV. Fermentations were launched with either liquid-propagated yeast or dried yeast, and the harvested yeast was then repitched through four generations. Throughout the process, we tracked fermentation kinetics, yeast physiology, beer chemical composition, and sensory outcomes.

Variation in G0 for both liquid and dry

One of the clearest findings was that the very first fermentation, Generation 0, stood apart from later ones. Both liquid and dried yeast behaved differently in G0 compared to G1 and beyond, reflecting the yeast’s shift from aerobic propagation to anaerobic fermentation. The effect was more pronounced with G0 dried yeast, and it is hypothesized to be due to the compounded stress of dehydration and rehydration during the transition from aerobic propagation to anaerobic fermentation. Additionally, inconsistencies in pitching rate — stemming from difficulties in standardizing viable cell counts between liquid and dry formats — may have contributed to the observed variation.

As a result, G0 fermentations with dried yeast showed more noticeable shifts in performance and in the flavor of the finished beer. This observation aligns with long-standing knowledge in the brewing industry: Brewers recognized the first generation of a yeast crop often tastes different from subsequent ones and many routinely blend G0 beer with later batches to smooth out flavor variation.

Variation vanishes after first repitch

The more important story, however, was what happened next. From the first repitch onward, dried yeast performed just as consistently as liquid yeast. Fermentation stabilized, flavor outcomes were steady, and no meaningful differences were detected between the two forms from G1 through G3. In terms of microbiological stability, dried yeast also proved equivalent to liquid yeast. Risks of contamination or genetic drift were no greater with dried yeast, provided that brewers began with clean yeast and maintained tight microbiological control during repitching.

Taken together, these results demonstrate that dried yeast can be repitched with the same reliability as liquid yeast, offering breweries not only the logistical and cost advantages of dry formats but also the confidence to carry yeast forward across multiple generations. For brewers, the key message is clear: dried yeast is not just for single-use pitching. It is a robust, repitchable option for producing consistent beer at scale.

About the author Jun Yomo, M.Sc., Visiting Scholar at Oregon State University

Originally from Japan, I completed my master’s degree in biology at graduate school of Kyoto University before joining Suntory in 2016, where I have been involved in beer brewing ever since. For the first four years, I worked as a brewer then spent the next four years on the R&D team developing fermentation control technologies. Through this experience, I became captivated by beer brewing, particularly the fermentation process orchestrated by yeast. In April 2024, I moved to the United States as a visiting scholar at Tom Shellhammer’s Lab at Oregon State University. I am conducting experiments on beer fermentation at OSU, while learning new technologies and product concepts for Suntory and, by extension, the Japanese beer market.

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