Issue link: https://read.dmtmag.com/i/63248
WINERY ine faults resulting from oxidation and reduction have been a focus of recent research, and an issue that alterna- tive-closure manufacturers seek to address. Nomacorc, a manufacturer of synthetic cork closures, and VinPerfect, a maker of screwcap closures, have introduced new products intended to provide consistent and predictable oxygen transmission rates (OTR) after bottling. These closures can be matched to wines to preserve and comple- ment their intended style, and to match their intended shelf life after bottling. THE NEED FOR OXYGEN MANAGEMENT The need to study oxygen in wine is highlighted by data from the annual International Wine Challenge in Lon- don, which has evaluated sensory faults found in wines entered in its judging since 2006. Between 2006 and 2010, an average of 6%-7% of all wines entered had detect- able faults. More than 50% of these faults were related to oxida- tion and reduction issues. A break- down of average percentages of the major faults for the five-year period showed 27% due to sulfides, 26% due to oxidation and 27% due to cork taint. Nomacorc, based in Zebulon, N.C., introduced its first co-extrud- ed synthetic wine closure in 1999 and is now the world's largest man- ufacturer of alternative wine clo- sures, with global sales of 2.4 billion closures in 2011. Since 2007, the company has worked with indepen- dent industry research institutions on every wine-producing continent to study the effects of oxygen on wines, and the effects of OTR on bottled wines. 42 VINEYARD & WINERY MANAGEMENT MAY - JUNE 2012 Predictable Oxygen Transmission Rates Closures Offer New Synthetics and screwcaps provide winemakers with options By Ted Rieger senior feature editor Nomacorc global director of enology Dr. Stephane Vidal uses the metaphor of a road to explain the concept of oxygen management in wine: "We want to drive to stay on this road between two ditches: an oxidation ditch on one side and a reduction ditch on the other." Wine oxidation occurs from too much oxy- gen exposure, resulting in discoloration and the loss of fruity and varietal aromas. Wine reduction occurs from too little oxygen expo- sure, and can result in expression of nega- tive sensory compounds, or masking of fruity and varietal aroma compounds. Many variables, such as the wine's chemistry and how it is processed, can influence its oxidation (or reduction) potential, and the time required for oxidation/reduction to occur. Wine preservation and sensory character are influenced by the wine's abil- ity and need to absorb oxygen, the amount of oxygen in the bottle at bottling and the closure's OTR, and the amount of free sulfur dioxide AT A GLANCE Oxygen management in wine doesn't end when the bottle leaves the winery. Managing oxygen in bottled wines requires balancing the need to preserve wine from oxidation with the need to prevent negative reduction characters. Synthetic cork closures and screwcaps can now be produced with predictable and consistent oxygen transmission rates. Closures can be matched to specific wines to preserve their intended style and shelf life. WWW.VWM-ONLINE.COM