Issue link: http://winesandvines.uberflip.com/i/465325
54 practical winery & vineyard March 2015 W I N E m A k I N G levels. 1 If the redox potential of a must is not increased during H 2 S formation (aerated must), the H 2 S can react with other com- pounds such as ethanol and sulfur-containing amino acids to form mercaptans (most notably, methyl mercaptan). However, the details of the mechanism of the formation of mercaptans are currently unknown. These molecules create a pungent, rotten cabbage aroma. Mercaptans can be easily oxidized to form a less aromatic disulfide. This misleads wine- makers to believe the problem has dissipated, although mer- captans can re-form under reductive bottle conditions. Yeast strains differ widely in their propensity to form H 2 S and are chosen based on this characteristic. Conclusion Wine is commonly referred to as a "complex matrix." By break- ing wine down into its fundamental components, we can begin to understand how to better manage our vineyards and winer- ies to attain the wine styles that consumers desire. Volatile fatty acids and sulfurous compounds that are purely microbially derived should be avoided. It is crucial to under- stand how these compounds arise and how winemakers and viticulturists can manage them effectively and efficiently. PWV Bibliography 1. Boulton, R., V. Singleton, L. Bisson and R. Kunkee. 1996 Principles and Practices of Winemaking. New York, NY. 2. Corison, C., C. Ough, H. Berg and K. Nelson. 1979 "Must acetic acid and ethyl acetate as mold and rot indicators in grapes. Am. J. of Enol. & Vit., 3 0 (2), 130–134. 3. Erasmus, D., M. Cliff, and H. van Vuuren. 2004 "Impact of yeast strain on the production of acetic acid, glycerol and the sensory attributes of ice wine." Am. J. of Enol. & Vit., 55, 371– 378. Reducing Losses on Wine Grape Sales Tools for wine grape growers and wineries working together to defi ne and document terms of sales This workshop will cover: protecting price, assuring delivery, using liens, fi ling UCC fi nancial statements and how to ensure a healthy and long term relationship between buyer and seller. Wednesday, March 18 Walla Walla: 8 to 11, Port of Walla Walla, 310 A Street Pasco: 1:30 to 4:30, Red Lion Hotel, 2525 North 20th Avenue Thursday, March 19 Prosser: 8 to 11, Walter Clore Center, 2140 Wine Country Road Yakima: 1:30 to 4:30, Yakima Convention Center, 10 North 8th Street Call 509.782.1108 to register. Cost is $30.00 Presented by: Washington Wine Industry Foundation in partnership with USDA 28th Annual International Wine Judging April 29 – May 2, 2015 Annually over 2,000 wines are professionally evaluated from over 15 countries and 34 states. Eminently qualified wine judges with extensive experience in all grape and "other than grape" varieties. Entry fee is $60 per label and only two bottles of each entry. Entry form at www.tastersguild.com or contact: TASTERS GUILD 1-888-887-9342 • email: joeb@tastersguild.com