| Growth of the yeast Brettanomyces/Dekkera in wine can drastically alter the aroma to the point where all varietal and regional characteristics are overwhelmed by the flavors produced by this yeast. To avoid spoilage it is important to know more about the aromas formed by this yeast and be able to detect the aroma changes early to prevent further yeast growth and aroma modification. Cabernet Sauvignon wines characterized by winemakers and wine experts as having strong, moderate, and no Brett character were analyzed using sensory descriptive analyses, GC/O, and GC/MS. In addition, a UV light method for controlling the further growth of yeast responsible for the production of Brett character in red wine was investigated.; The a priori Brett character aroma observations by the winemakers were consistent with the results from the two separate sensory descriptive analyses and the GC/O analyses. ‘Plastic’ and ‘fruity’ were the only descriptors that proved to be a consistent predictor of Brett character. The greatest ‘fruit’ character and the lowest ‘plastic’ scores defined the younger Cabernets, and the opposite was true for the older wines.; Primary odorants identified by GC/MS and GC/O include isovaleric acid, 2-phenyl ethanol, 3-methyl butanol, ethyl-2-methyl butyrate, β-damascenone, cis-2-nonenal, trans-2-nonenal, guaiacol, 4-ethyl phenol, and 4-ethyl guaiacol. The ethyl phenols, isovaleric acid, cis-2-nonenal, trans-2-nonenal, and the two unidentified ‘plastic’ compounds were the indicator compounds for Brett character.; Brettanomyces bruxellensis, as well as Saccharomyces cerevisiae strains were sensitive to the germicidal properties of UV light. A 2–6 log reduction in yeast populations was observed in red wine, white wine, and water. UV light was less effective in red wine reducing the Brettanomyces population by 2.3 log. The high cell density of yeast and the composition of the fluids did not appear to quench the UV light. Further studies should evaluate the organoleptic and photochemical changes that may occur with the use of UV light on wine. |
