Determination of the Optimum Amount, Rate, and Exposure Point of Microoxygenation for Cabernet Sauvignon
Anibal Catania, Larry Lerno, Charles Brenneman, and Anita
Oberholster*
*Department of Viticulture and Enology, University of California,
Davis, CA 95616
(aoberholster@ucdavis.edu)
The controlled addition of small amounts of oxygen to young red wines is known as microoxygenation (MOX). MOX is used during red wine production fairly commonly to increase color density, fruity aromas, and polymeric pigments. Prior research on MOX focused primarily on the comparison of MOX at a single oxygenation rate to non-MOX wines, with the optimum amount and rate of oxygen exposure not being investigated. The amount and rate of oxygenation must be balanced with the wine’s specific chemical composition to prevent detrimental effects. To investigate the optimum amount and rate of oxygen exposure, as well as the point of exposure during vinification, a Cabernet Sauvignon was produced at the UC Davis Teaching and Research Winery during the 2014 harvest. Following primary fermentation, the wine was subdivided into two treatment lots, one receiving no oxygen and the other, 20 mg/L/month oxygen for 30 days prior to malolactic fermentation (MLF). After completion of MLF, each treatment was cold-settled and subdivided into treatments that received 0, 4.5, or 9 mg/L/month oxygen for five months. Starting at the end of alcoholic fermentation, all treatments were sampled regularly to determine dissolved oxygen, total and free SO2, chromic properties by UV-VIS spectroscopy, phenolic content by RP-HPLC and the Adams-Harbertson Assay, polymeric pigments by LC-MS/MS, and acetaldehyde by RP-HPLC. Descriptive analysis will be performed on bottled wines six months posttreatment (March 2016) with concurrent phenolic analysis. At the end of treatment, wines that received both pre- and post-MLF MOX had more polymeric phenols, polymeric pigments, color density, and hue than the control and wines given only post-MLF MOX. Analysis of the concentration of acetaldehyde during MOX showed little to no buildup during oxygenation.
Funding Support: Unfunded researc
