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82 WINES&VINES November 2018 WINEMAKING PRACTICAL WINERY & VINEYARD The short answer is no. Very high SO 2 risks exceeding legal limits, results in bleaching of red wine color and may disrupt the normal élevage of wine. Further- more, many red wines appear to be stable even if they contain less than normal targets for molecular SO 2 concentrations–perhaps be- cause of other factors such as low microbial contamination level, low available nutrients and impact of temperature (or perhaps recom- mended targets are too high). Instead, an HS-GDT measurement could indicate when more diligence is needed in monitoring risky wines – that is, those wines with very low concentrations of molecular SO 2 due to the presence of anthocyanins and other weak SO 2 binders. However, the HS-GDT method is not automated, so it is best suited for small-scale wineries, or to check specific wines that may be at high risk for microbial spoilage and therefore subjected to more strin- gent controls prior to bottling. For example: • Sweet or off-dry red wines, due to re- sidual sugar content, • Unfiltered, or not sterile-filtered red wines, • Barrel-aged red wines, especially in old barrels that may be infected with Brettanomyces, • Young red wines, due to the high quan- tity of monomeric anthocyanins present in young reds and their tendency to form anthocyanin-SO 2 complexes. It is evident that free SO 2 (and not just molecu- lar SO 2 ) will be overestimated by conventional approaches. Free SO 2 is involved in antioxidant reactions in wine, and further research will be necessary to determine if conventional or GDT measurements are better suited to predicting the occurrence of both desirable (pigment stabiliza- tion) and undesirable (oxidized aroma formation) oxidative reactions during storage. This article is based on the publication "Conventional Measurements of Sulfur Dioxide (SO 2 ) in Red Wine Overestimate SO 2 Antimicrobial Activity" by Patricia A. Howe, Randy W. Worobo and Gavin L. Sacks. American Journal of Enology & Viticulture, 69(3) 2018. ajevonline. org/content/early/2018/02/23/ajev.2018.17037) Raquel Kallas was a viticulture support specialist with Cornell University's New York Statewide Viticulture Extension Program. Gavin Sacks is an associate profes- sor of food science at Cornell University. Patricia Howe is director of wine technical services at Constellation Brands in Napa, Calif. Randy Worobo is a professor of food microbiology at Cornell University. Statement of the Ownership, Management, and Circulation, as required by the Act of Congress of October 23, 1962, Section 4369, Title 39, United States Code. Wines & Vines, published monthly in San Rafael, CA. 1. The date of this filing is September 25, 2018. 2. The location of the office of the publisher is 65 Mitchell Blvd, Ste. A, San Rafael, CA 94903. 3. The name and address of the publisher is: Chet Klingensmith, 65 Mitchell Blvd., Ste. A, San Rafael, CA 94903. The name and address of the editor is: Andrew Adams, 65 Mitchell Blvd., Ste. A, San Rafael, CA 94903. 4. Wines & Vines is owned by Wine Communications Group, a California corporation. 5. For the year preceding this filing: Average number of copies printed per issue: 5,169 Paid circulation average: 3,041 Free circulation average: 1,949 Total print distribution average: 4,990 Digital circulation: 9,702 Total print and digital circulation average: 14,692 6. For the single issue printed nearest the filing date: Number of copies printed: 4,629 Paid circulation: 2,989 Free circulation: 1,483 Total print distribution: 4,472 Digital circulation: 9,702 Total print and digital circulation: 14,174 I certify that the above statements are correct and complete. Chet Klingensmith Publisher, Wines & Vines Reduction in yeast cell counts as a function of molecular GDT SO 2 (left) and molecular AO SO 2 (right) during chal- lenge experiments on red and white wines. FIGURE 4: YEAST SURVIVABILIITY BY SO 2 MEASUREMENT METHOD Change in cell counts compared to no SO 2 control (log CFU/mL) 0.5 0 -0.5 -1 -1.5 -2 -2.5 -3 -3.5 Molecular GDT SO 2 (mg/L) n White n Red 0.22 0.69 Change in cell counts compared to no SO 2 control (log CFU/mL) 0.5 0 -0.5 -1 -1.5 -2 -2.5 -3 -3.5 Molecular AO SO 2 (mg/L) n White n Red 0.25 0.67 Winery Online Marketing System Grower Online Marketing System Brewer Online Marketing System Distributor Market Service Distillery Database Custom Data Reports REACH MORE DECISION MAKERS • WINES & VINES DATA SERVICES winesandvines.com • winesandvines.com/databases