Composition of Tannins Extracted into Red Wine Emphasizing the Relative Amount of Skin and Seed Tannin

The goal of this proposal is to develop an analytical method to measure seed and skin tannin extraction during red wine fermentations, and to use this method to explore the relative significance of seed and skin tannins in red wine. With this technique, an improved understanding of the influence of viticultural and winemaking practices on wine composition and flavor will be achieved. To date, development of the analytical method is nearing completion. The method utilizes high performance liquid chromatography to analyze the composition of the grape source material as well as the finished wine. Based upon this information, the amount and proportion of skin and seed tannin can be determined. The method is reproducible and accurate. The final method will be used to monitor several experiments. These experiments include both vineyard and winery experiments designed to potentially affect the proportion of skin and seed tannins in wine. Experiments are being conducted on Pinot noir grapes and wine, with plans to include other varieties as well. Viticulture experiments include: a clonal variation experiment, ethanol application and maturity effects on tannin extraction in red wine. Enology experiments include: variations in cold soak time and enzyme addition.