Oxygen Contribution to Wine during Bottle Aging
This Nomacorc document offers an excellent review of TPO and the place of closures in the overall wine aging scheme. It demonstrates that permeation after bottling is important to wine quality despite the relatively small amount of oxygen involved when compared to earlier winemaking efforts. Unfortunately, Nomacorc includes some absurd values to represent permeability with natural cork. The presentation highlights the variability of cork (page 6131). Plugging in the OTR numbers reported by Lopes, and the paper makes an excellent case for cork stoppers.
Recalling a confrontation we had at a UC Davis event, he introduces a paragraph claiming the DMS is not affected by oxygen levels. (He interrupted my UCD presentation to claim that DMS was "absorbed" by cork) Eric Herve came to my defense (afterwards). The footnotes for his claim on DMS credit his own research.
The study also offers extensive review of the effect of large oxygen additions on many other wine compounds. Of particular interest was the effect of oxygen on volatile thiols.
Oxygen Contribution to Wine Aroma Evolution during Bottle Aging
Maurizio Ugliano (Nomacorc)
ABSTRACT: Wine aroma undergoes major changes during bottle aging, which are deeply influenced by the degree of oxygen exposure in the bottle. This review discusses the involvement of oxygen in the main chemical transformations occurring in wine aroma composition during bottle aging, with particular emphasis on the formation of oxidative aroma compounds and formation/degradation of sulfur-containing volatile compounds. The implications for wine sensory properties are discussed, as well as some practical aspects of oxygen management during bottle aging, including the role of closure oxygen permeability.
J.Agric. Food Chem. 2013, 61, 6125-6136