MB4 -- Comparison of Cell Counts in Re-pitched Irish Ale and Pacific Ale Yeast Strains
Start Date
8-4-2022 10:30 AM
End Date
8-4-2022 12:15 PM
Location
URC Greatroom
Document Type
Event
Abstract
Prior to 1880s, it was a common practice for beer brewers to use a combination of yeasts species to ferment beer. With the advancement of scientific technology and knowledge, the use of pure yeast cultures gradually became the norm in the beer industry. The use of single yeast strains allowed brewers to standardize beer styles and flavors. This practice also allowed brewers to re-use, or re-pitch, yeast cultures for multiple batches of beer to minimize costs. Most breweries are still using pure yeast strains for their beer production. However, some brewers are beginning to revisit historical yeast blends and starting to develop new yeast blends to increase diversity in beer flavors and fermentation performance. Although there is potential with these blends, mixing yeast strains has created questions on how strains could interact and what characteristics they could exhibit in beer. Yeast cell concentration and dominance of one strain over the other makes consistent re-pitching of yeast cultures problematic, thereby, potentially limiting the blend to a single use for beer production. In this study, yeast cell counts were examined from beers prepared from two commonly used ale yeast strains - Pacific Ale (WLP041) and Irish Pale Ale (WLP004) yeasts from White Labs in Asheville, NC. Even though both ale yeast strains belong to the species Saccharomyces cerevisiae, the beers brewed using each of these strains has their own their own distinct characteristics. This study aimed to analyze how re-pitching a 50:50 blend of Pacific Ale (WLP041) and Irish Pale Ale (WLP004) yeasts could influence yeast cell concentration and fermentation performance in subsequent generations. The findings indicated that yeast cell counts harvested from the second and third generation blend beers were not significantly different from the yeast cell counts harvested from the second and third generation single strain beers. The results also showed that the attenuation rate and alcohol content (ABV) of the Irish Ale single strain and 50:50 blended second generation beers were very similar. Among the second generation beers, the attenuation rate and ABV of the single strain Pacific Ale beer was less than the single strain Irish Ale and the 50:50 blend beers. Although most pure yeast strains are very well characterized there is currently limited research and information on how they interact with other strains during beer production. This preliminary study has started screening process of yeast blends for beer production.
Keywords
Cell Molecular Biology
MB4 -- Comparison of Cell Counts in Re-pitched Irish Ale and Pacific Ale Yeast Strains
URC Greatroom
Prior to 1880s, it was a common practice for beer brewers to use a combination of yeasts species to ferment beer. With the advancement of scientific technology and knowledge, the use of pure yeast cultures gradually became the norm in the beer industry. The use of single yeast strains allowed brewers to standardize beer styles and flavors. This practice also allowed brewers to re-use, or re-pitch, yeast cultures for multiple batches of beer to minimize costs. Most breweries are still using pure yeast strains for their beer production. However, some brewers are beginning to revisit historical yeast blends and starting to develop new yeast blends to increase diversity in beer flavors and fermentation performance. Although there is potential with these blends, mixing yeast strains has created questions on how strains could interact and what characteristics they could exhibit in beer. Yeast cell concentration and dominance of one strain over the other makes consistent re-pitching of yeast cultures problematic, thereby, potentially limiting the blend to a single use for beer production. In this study, yeast cell counts were examined from beers prepared from two commonly used ale yeast strains - Pacific Ale (WLP041) and Irish Pale Ale (WLP004) yeasts from White Labs in Asheville, NC. Even though both ale yeast strains belong to the species Saccharomyces cerevisiae, the beers brewed using each of these strains has their own their own distinct characteristics. This study aimed to analyze how re-pitching a 50:50 blend of Pacific Ale (WLP041) and Irish Pale Ale (WLP004) yeasts could influence yeast cell concentration and fermentation performance in subsequent generations. The findings indicated that yeast cell counts harvested from the second and third generation blend beers were not significantly different from the yeast cell counts harvested from the second and third generation single strain beers. The results also showed that the attenuation rate and alcohol content (ABV) of the Irish Ale single strain and 50:50 blended second generation beers were very similar. Among the second generation beers, the attenuation rate and ABV of the single strain Pacific Ale beer was less than the single strain Irish Ale and the 50:50 blend beers. Although most pure yeast strains are very well characterized there is currently limited research and information on how they interact with other strains during beer production. This preliminary study has started screening process of yeast blends for beer production.