• The impact of grape clone, yeast strain and protein on sparkling wine quality

      Onguta, Esther; Centre for Biotechnology
      The foaming properties in sparkling wine are an indicator of quality as it is the first quality perception consumers have upon opening a bottle of sparkling wine. Proteins, which are derived from both grapes and yeast during sparkling wine production, are known to impact the foaming properties in finished sparkling wines. The objectives of this project were to (1) understand the role and relationship that proteins have on the overall foaming properties and overall quality in sparkling wine, (2) determine the role different yeast and grape clones from different varietals have on sparkling wine quality and (3) understand how bentonite affects sparkling wine quality. The protein concentration in sparkling wine produced from Mariafeld Pinot noir appeared to impact the foaming properties. The longest elapsed time for foam dissipation was observed in the control treatment where bentonite was not used to strip protein and the shortest time was observed in the treatment where bentonite was used to remove grape and yeast proteins. In Riesling sparkling wines, the largest protein concentrations were observed in non-bentonite treated juices while the lowest were observed in the bentonite treatments. The prevalence of foam observed in both bentonite treatments, where grape proteins were completely removed, indicated that proteins derived over the course of secondary fermentation were foam forming in Riesling sparkling wine. It was also observed that different yeast, varietals, clones and soil compositions may impact the protein concentrations, chemical compositions and overall quality of sparkling wine. The results of this research aim to better understand sparkling wine quality to optimize production in the Niagara Peninsula.