Grant: Engage Grants for universities

Non-Saccharomyces, Saccharomyces spp. other than Saccharomyces cerevisiae, and S. cerevisiae are three_x000D_ groups of yeasts that are involved in winemaking. Based on results from previous Engage and CRD grants, we_x000D_ found that spontaneous fermentations, conducted in the Okanagan, are completed primarily by commercial S._x000D_ cerevisiae strains that the winery has used as an inoculant. In 2015, our group studied Chardonnay_x000D_ fermentations and we surprisingly found that Saccharomyces uvarum, a cryotolerant Saccharomyces yeast, was_x000D_ able to dominate and complete fermentations that were started at 12C. Both S. uvarum and S. cerevisiae_x000D_ tolerate relatively high SO2 and alcohol concentrations, but S. uvarum can also affect the wine aroma and_x000D_ flavour differently than S. cerevisiae. We do not know whether the identification of S. uvarum from the 2015_x000D_ vintage was an anomaly or whether it will be a consistent trend associated with the Mission Hill Family Estate_x000D_ Winery (MH) or if this trend occurs at other wineries that harvest their grapes in a similar area as does MH. We_x000D_ will be repeating the spontaneous fermentations at MH in the 2017 vintage using Chardonnay grapes. For_x000D_ comparison purposes, we will conduct the identical experiment at Tinhorn Creek Vineyards (TCV). Thus, the_x000D_ objectives of this proposal are to: 1) develop a research partnership between UBC Okanagan and TCV; 2) to_x000D_ compare the Saccharomyces and non-Saccharomyces yeast composition of lab and winery fermentations so as_x000D_ to determine whether the origin of yeasts were from the vineyard, winery or from both; 3) to compare the yeast_x000D_ composition in fermentations that differ by having grapes sourced from different vineyards (one close and one_x000D_ far away from the winery). Our results will provide information to TCV winemakers, helping them in their_x000D_ selection and management of yeasts, which will help them improve wine quality and reduce costs. Since TCV_x000D_ will continue to conduct spontaneous fermentations in their Chardonnay varietals and will continue sourcing_x000D_ Chardonnay grapes from these two vineyards, knowing the yeast in these fermentation treatments will help_x000D_ them in their management decisions.