In the past, tall cylindrical fermenters, replacing short brewing vats, tended to adversely affect the taste of the finished beer, but now scientists are working to improve the taste of beer. intervening.
These taller tanks produce more beer for less money and are easier to fill, boil dry, and clean, but their widespread use creates excess pressure from the carbon dioxide produced during fermentation, which reduces the taste. It can also have an impact.
The researchers first identified strains of the yeast Saccharomyces cerevisiae that are particularly tolerant of CO2, and focused on the production of isoamyl acetate, which gives beer its fruity banana flavor.
Finding a particularly strong strain, the researchers used whole-genome sequencing to determine why the strain was able to retain its fruity flavor under the pressure of modern fermentation tanks.
“This gene appears to be involved in the production of isoamyl acetate, the banana flavor ingredient that was largely responsible for this yeast’s pressure resistance,” says molecular biologist Johann Theverein of the University of Louvain, Belgium. says.
This discovery allowed researchers to use CRISPR/Cas9 gene-editing technology to incorporate the same mutation into other yeast strains. After editing, these strains were able to withstand CO2 pressure and retain their taste better.
In addition, many yeasts can be modified in the same way to produce beers with stronger flavors when poured.
So far, the yeast’s other traits don’t seem to be affected by genetic modification.
“This mutation provides the first clue as to the mechanism by which high carbon dioxide pressure impairs the flavor of beer,” says Thevelein.
Until now, the impact of high CO2 pressure on beer flavor has been unclear at the molecular level, although the end result of reduced fruity flavor is easily felt.
In the future, he hopes to run experiments at even higher CO2 pressures to see if different genes are identified. In this study, MDS3 dominated, although other genes also showed promise.
The same genetic identification technique has been used previously to reveal other important yeast traits, such as glycerol (a sugar alcohol that enhances flavor) production and tolerance to high temperatures.
The authors candidly state that the research was supported by a liquor company, which hopes to exploit the technology as a patent.
While other beer brands may not be able to take advantage of this technology, this study shows the potential benefits of applying CRISPR to modify the yeast’s flair to create exceptional drops.
“This study shows great potential for creating cisgenic industrial brewer’s yeast strains with specifically enhanced traits through polygenic analysis and targeted gene modification,” the researchers said in a published paper.
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