The oxygen transfer rate (OTR) of closures is a well-known parameter impacting the quality of Sauvignon blanc wines (SBw) within the first years of storage, but little research has been published on its long-term effects. The chemical changes in oxidation odor intensity in three SBw sealed with natural cork and other closures that had different known OTRs, ranging from <0.1 to 4.6 mg/year, were monitored over a 10 year period. During aging, free SO2 and 3-sulfanylhexanol loss, concomitant with increases in dissolved O2, OD420, and sotolon, were correlated with closure OTR levels. After 10 years of aging, sensory analysis was conducted, supported by additional chemical analysis of aroma impact markers, including methional, phenylacetaldehyde, 2-furanmethanthiol, 4-methyl-4-sulfanylpentan-2-one, ethyl-2-sulfanylacetate, and hydrogen sulfide, as well as total SO2 and dissolved CO2. These analyses revealed that selected SBw were protected from oxidation over a 10 year aging period, provided that the closure OTR did not exceed 0.3 mg/year.

Cork stoppers have been used for many centuries to seal wine in various vessels. Therefore, corks have become a traditional part of wine packaging in many countries and still play an important role for the entire wine industry. Nowadays, there is a wide option of bottle cork stoppers on the market, such as natural corks, agglomerated and technical stoppers (1 + 1), etc. These cork closures have a number of advantages, including positive sustainable and ecological aspects. Natural cork material can also be responsible for cork taint, which imparts musty/moldy or wet cardboard off-odors to the wine. However, corks are not the only source of cork taint in wine, as will be shown in the present chapter. Over the past decades, a number of compounds have been detected that can contribute to the cork taint. Among them, haloanisoles play a major role, in particular 2,4,6-trichloroanisole (TCA), which has been shown to be responsible for 50–80% or more of musty defect cases in wine. Currently, the cork and wine industries have developed a number of tools and technologies to effectively prevent cork tait in wine or to remove it if the wine is already contaminated. These practical as well as analytical questions about the TCA defects are the subject of the actual chapter.

Dimethyl sulfide (DMS) is a flavor compound, characteristic of the truffle aroma in red wines, and is well-known to be a fruity exhauster. DMS comes from the degradation of dimethyl sulfide potential (DMSP) during winemaking. Up to now, little is known about the role of the closure on the DMSP degradation during ageing. For that purpose, the effect of four micro-agglomerated wine cork closures was studied on the DMS/DMSP equilibrium, along with six other volatile sulfur compounds (VSC), was investigated in six Shiraz wines. After three months of accelerated bottle ageing, DMS levels increased significantly in all bottles. The most permeable closures induced a lesser accumulation of DMS, suggesting that DMS could be dependent on the redox status of the wine. At the same time, the DMSP decrease was proportional to the permeability of the closures. For the first time, a possible implication of closure permeability on DMSP degradation was observed.

Storage temperature is one of the most important factors affecting wine aging. Along with bottling parameters (type of stopper, SO2 level and dissolved O2 in wine), they determine how fast wine will evolve, reach its optimum and decline in sensory quality. At the same time, lowering of the SO2 level in wine has been a hot topic in recent years. In the current work, we investigated how Riesling wine evolved on the molecular level in warm (~25 °C) and cool (~15 °C) conditions depending on the SO2 level in the wine (low, medium and high), flushing of the bottle’s headspace with CO2 and three types of stoppers (Diam 30, Diam 30 origin and Diam 5) with different OIR levels (0.8–1.3 mg) and OTR levels (0.3–0.4 mg/year). It was demonstrated that the evolution of primary and secondary aromas, wine color and low molecular weight sulfur compounds (LMWSCs) during the two years of aging mainly depended on the storage temperature. Variation in the SO2 level and CO2 in the headspace affected mostly certain LMWSCs (H2S, MeSH) and β-damascenone. New aspects of C13-norisprenoids and monoterpenoids behavior in Riesling wine with different levels of SO2 and O2 were discussed. All three types of stoppers showed very close wine preservation properties during the two years of storage. The sensory analysis revealed that, after only six months, the warm stored wines with a low SO2 level were more oxidized and different from the samples with medium and high SO2 levels. A similar tendency was also observed for the cool stored samples.

This study evaluated the impact of closure type on unoaked 100 %-Merlot, oak-aged 70%-Merlot/30%-Cabernet Sauvignon, and 30%-Merlot/70%-Cabernet Sauvignon during a 10 year period. Closures were microagglomerate corks, screw caps, and synthetics with the known oxygen transfer rate (OTR), ranging from 0.1 to 4.6 mg/y, including natural corks. Oxidation intensity perception, dissolved oxygen, sulfite, and 3-methyl-2,4-nonanedione (MND) were monitored on a regular basis. After 10 years of aging, additional aroma impact markers were evaluated (3-sulfanylhexan-1-ol, H 2 S, DMS, methional, and phenylacetaldehyde). Low OTR levels (≤0.3 mg/y) delayed the oxidation of red wines in this long-term experiment. In addition, our results led us to hypothesize that the MND concentration in young wines might be linked with their ability to produce it during bottle aging that is with their aging potential. Finally, we found that the kinetic accumulation of MND in wines was first strongly impacted by its intrinsic composition and thereafter by the OTR T0 of the stopper.