Project Number: 5358-12210-002-01
Project Type: Specific C/A

Start Date: Sep 09, 2004
End Date: May 31, 2006

Objective:
Identify the extent of vineyard variability in commercial Pinot noir vineyards that have been divided into blocks based upon differences in wine composition. Study the relationship between vineyard variability and wine composition. Determine the extent to which production practices can be used to manage vineyard variability and to manipulate grape composition. Isolate and purify tannins from musts/wine samples obtained from four commercial scale fermentation at up to 5 times during maceration. Fully characterize these tannins in terms of composition, source (skin vs. seed), and the presence of other, non-tannin material (i.e. color, polysaccharide). Determine how these tannin isolates interact with protein. Isolate sufficient quantities for sensory studies.

Approach:
Four commercial vineyard blocks, managed by two wineries, were selected for study and characterized (soil characterization, chemistry, GPS mapping, trunk cross sectional area, and vine growth). At commercial harvest, triplicate grape samples will be collected from the monitored blocks and pH, TA, sugar, available nitrogen, phenolics, and will be determined for comparison with wines. Extract analysis will include measurement of anthocyanins, hydroxycinnamates, and flavonols. Tannins will be analyzed with a combination of chromatography techniques. Finished wines will be analyzed for the following: alcohol content, volatile acidity, pH, visible color analysis, and complete phenolic profile and flavor. Grapes will be selected for study, and four vineyard sites, two for each variety, will be selected for wine production based on historical differences in wine texture. Wines will be produced using existing winery methods. Must/wine will be collected at specific times during maceration and immediately following punchdown/pumpover operations. For tannin isolation, musts/wine will be passed through a low-pressure chromatography column containing Fractogel resin. Purified tannin will be analyzed for the following: purity, extension and terminal subunit concentration, degree of polymerization, mass distribution, proportion of skin vs. seed tannin, color, and sugar. Documents SCA with OSU.

Project Team

Schreiner, R - Paul James Kennedy - Assistant Professor 541-738-4084

Related National Programs

Plant Biological and Molecular Processes (302)   Plant Diseases (303)