ArticlePreventing Oxidation, Excess SulfiteWritten by Alison CroweI need help to prevent oxidation. I make about 40 gallons (151 L) from California grapes each year, usually finishing quite nice, but last year’s Sangiovese suffers from oxidation. After fermentation and pressing, the wine spends the next ten to eleven months in carboys fitted with airlocks. I rack at least three times throughout the year by the siphon method. Should I try using carbon dioxide whenever I rack to expel oxygen. Or should I bottle sooner? Sam Chiodo via email I have to commiserate with you on the Sangiovese and oxidation dance. For some reason, this grape varietal seems to be especially prone to color (and related oxidation) issues. Much like Pinot Noir, Sangiovese lacks some of the colored precursors that help a wine age gracefully. Some of the compounds that form high color are, in themselves, antioxidants, which is part of the reason a Cabernet or Petite Sirah (both pretty dark-colored wines) tend to resist the oxidative ravages of time. Therefore, even though Sangiovese grapes normally come in with nice acidity levels (which helps to set and stabilizeAlready a member? Log InYou'll Also Like Article MEMBERS ONLY Top Me Off, Rules of Fining, and Achieving Cold Stable Wines Get some pointers and considerations a winemaker needs to keep in mind when topping off your aging wine vessels. The Wizard also answers questions on fining agents and malolactic fermentation after cold stabilizing a wine. Article MEMBERS ONLY Yeast-free wine and quality control: Wine Wizard The good news is that most wines that you can buy off the supermarket shelf don’t contain a lot of yeast cells; if they did, the wines would look cloudy and might even re-ferment in the bottle.