Grant: Engage Grants Program

Wine is created by the fermentation of sugars in red or white grape juice to ethanol, mainly by the wine yeastSaccharomyces cerevisiae (S. cerevisiae). Two methods are used: spontaneous fermentation, where yeastpresent on the grapes from the vineyard or on winery equipment carry out the fermentative process; andinoculated fermentation, where a commercially prepared, single strain S. cerevisiae inoculum is used.Spontaneously fermented wines are characterized by a diversity of yeast species and strains that varies byregion. This diversity can result in wines with more sensory complexity and regional character than winesproduced by inoculated fermentation; however, spontaneous fermentations are subject to greater risk ofoxidative yeast spoilage and if present in the winery, commercial S. cerevisiae strain contamination. SouthOkanagan winery Stoneboat Vineyards (SBV) spontaneously ferments their flagship, award-winning PinotNoir, and they believe this process may significantly contribute to wine quality.In this project, we will identify the yeast species (both S. cerevisiae and non-S. cerevisiae species) in SBV'sthree vineyard sites and spontaneous fermentations using two methods: next generation sequencing andmicrosatellite analysis. We will also compare vineyard yeast populations to populations in winery spontaneousfermentations. This will allow us to assess the impact of the winery environment on yeast populations inspontaneous fermentations and determine whether commercial S. cerevisiae strains are present. Potentiallyuseful yeast strains indigenous to their vineyards will be identified. By identifying the beneficial and spoilageyeasts present in the vineyard and winery, SBV can modify its fermentation protocols to enhance beneficialyeast growth, potentially reducing costly spoilage and sluggish fermentation issues. Additionally, SBV couldconduct further experimentation on potentially useful yeast isolates. This research will also generate moreinformation on British Columbian wine region yeast ecology and, as in other wine regions, will likely revealnovel yeast species and strains that can be exploited to enhance the regional character and quality of wine.