Investigation of Pre- and Post-Fermentation Alcohol Adjustments on Sauvignon blanc Wines Harvested at Three Maturities
Danielle Fox, Thomas Collins, and James
Harbertson*
*Washington State University, 2710 Crimson Way, Richland, WA,
99354-1671 (danielle.j.fox@wsu.edu)
Harvest and alcohol concentration are known to have significant effects on wine aroma and taste attributes. In this experiment we added dealcoholization to a maturity trial to better understand the effects of alcohol on sensory attributes. Sauvignon blanc was harvested at three different maturities (19, 22, and 25 Brix). At each harvest, alcohol was controlled by either chaptalization or dilution for the pending/ previous harvests. Dealcoholization was used to lower the alcohol of the medium-and high-alcohol treatments by ~2.0% (v/v) to match the lower treatments. Basic wine chemistry showed statistical differences by harvest for all analysis. The alcohol treatment showed significant differences for alcohol, RS, and pH. The dealcoholization treatment was significant for alcohol and TA. Descriptive analysis was carried out with 12 panelists (seven female, five male). All taste attributes were significant, while nine of 16 aroma attributes were significant. Principal component analysis showed that wines separated based on alcohol and harvest. Generally, higher-alcohol wines associated with hot, viscous, bitter, and alcohol, while lower-alcohol wines were associated with boxwood, sour, and sweaty attributes. Later-harvest wines were found to be more briny and herbal while earlier-harvest wines had more grapefruit, melon, and sour candy attributes with greater overall intensity. Analysis of variance showed that harvest was significant for most aroma attributes and three of the taste attributes (sweetness, bitter, and sour). The alcohol treatment was primarily significant for all five taste attributes. However, several aroma attributes appeared sensitive to the alcohol treatment (citrus, grapefruit, and honey). Overall, harvest and alcohol dominated the sensory profile of the wines. Dealcoholization results suggest this technology can be used to mimic wines made from less-mature or diluted juice. Gas chromatography-mass spectrometry will be used to evaluate chemical and sensorial effects.
Funding Support: This research was funded by Washington State University, Auction of Washington Wines and all Washington State winegrape growers and wineries through the Washington State Wine Commission.
