Irish Beer has a Genetically Unique Yeast in Guinness

The yeast strain used to brew Guinness, Ireland's traditional stout, is genetically different from the yeast strains used to make other Irish beers.

Brewer's yeast (budding yeast) is an essential element in beer production. During fermentation, these microorganisms convert sugars from malt into alcohol and carbon dioxide. Using different strains of this yeast can result in different types of beer, such as stouts and lagers, and can also affect its flavor profile.

Daniel Kerruish A research team from food and drink company Diageo Ireland Unlimited has determined which yeasts are used to brew Guinness, based on records kept by the Guinness brewery since 1903 of the yeast strains used in its malty, bitter stout. investigated its evolution over many years.

The research team compared the genomes of 13 strains. S. cerevisiae There are up to 160 different strains, including those currently or historically used to brew Guinness, and six used by other Irish breweries.

Although Guinness yeast and other Irish brewer's yeasts belonged to the same lineage, Kerruish and his team discovered that they were genetically distinct enough that Guinness yeast belonged to a previously unidentified subpopulation. Did. Irish brewer's yeasts, other than Guinness, were more closely related to strains of British origin.

Guinness strains were also found to produce a particular balance of flavor compounds, including 4-vinylguaiacol, which produces a subtle clove-like aroma, and diacetyl, which imparts a buttery taste.

The research team also discovered that the two strains currently used in Guinness are descendants of the strain used to brew stout in 1903.

“The more we learn about Guinness yeast, the more we realize how unique and special it is,” says Keluisch. “Guinness is a great beer, so it probably won’t surprise you.”

“What's particularly unique and exciting about this study is that the company has very detailed records of past handling of the strains,” he says. brian gibson at the Technical University of Berlin, Germany. “This information could be used to further develop these yeasts and others used in industrial applications.”