Profiling potential brewing yeast from forest and vineyard ecosystems

Area of Science:

• Microbiology
• Fermentation Science
• Food Science

Background:

• The craft beer industry seeks novel yeast strains for unique aromas and flavors.
• Utilizing local yeast strains supports the use of proximity ingredients in brewing.
• Wild yeast offers a diverse genetic resource for brewing innovation.

Purpose of the Study:

• To analyze and compare the brewing ability of wild yeast strains from forest and vineyard ecosystems with commercial strains.
• To identify potential new yeast starters for the craft beer sector.
• To understand yeast enzymatic profiles and their fermentation activity in response to beer ingredients.

Main Methods:

• Screening of 76 wild yeast isolates and 18 control strains for enzymatic activity and brewing capacity.
• Utilizing a microvolume screening system for rapid characterization of enzymatic activity, wort sugar utilization, and tolerance to hop acids and ethanol.
• Testing 28 selected strains in small-scale fermentations.

Main Results:

• A microvolume screening method enabled affordable and rapid characterization of a large number of yeast samples.
• Twenty-eight promising yeast strains were selected for further small-scale fermentation trials.
• Three strains of Lachancea thermotolerans exhibited significant potential and adaptability for fermenting diverse wort styles.

Conclusions:

• Wild yeast, particularly Lachancea thermotolerans, presents a viable source for developing new beer flavors and aromas.
• The developed screening system efficiently identifies yeast strains with desirable brewing characteristics.
• Further research is needed to fully evaluate the potential of these wild yeast strains as commercial beer starters.