Dimethyl sulfide transfer through wine closures during bottle aging: implications for wine aroma management

Abstract

Dimethyl sulfide (DMS) is a volatile sulfur compound with a complex role in wine aroma, contributing both desirable and undesirable sensory characteristics depending on its concentration (1). While DMS is known to accumulate during bottle aging through the degradation of precursors such as S-methylmethionine (SMM) (2), this study provides the first demonstration that DMS can also be lost through wine closures via permeation mechanism. This phenomenon, previously unreported, highlights the critical role of closure permeability in shaping the aromatic profile of aged wines.

In practice, we used 3 different experimental designs:

• Set 1: model wines spiked with DMS (n=3) and unspiked ones (n=3, control) were bottled and sealed with same micro-agglomerated closures. Bottles were then equipped with ®Tenax tubes to capture volatiles at the top of the bottles after vertically ageing at 35°C.
• Set 2: model wines were spiked with synthetic SMM, bottled and sealed with 4 closures of varying oxygen transfer rates (OTR). Accelerated aging experiments were conducted at 35°C for 4 months and corresponding wines were analysed in terms of SMM and DMS at t4months.
• Set 3: To validate findings, similar analyses were performed on Syrah wines aged 2 years in standard cellar conditions with closures of varying OTR. These wines were analysed at t0, t12 months and t24 months in terms of SMM and DMS.

The results obtained in the set 1 demonstrated the phenomenon of DMS permeation through closures, as DMS was detected only in ®Tenax tube placed on the top of the bottles containing the spiked solution. In the set 2, accelerated aging experiments revealed that up to 12% of DMS in model wine was lost through micro-agglomerated closures. Finally, in Syrah wines, DMS concentrations increased during bottle aging due to SMM degradation. However, wines sealed with higher-permeability closures showed reduced DMS levels compared to those with low-permeability closures, corroborating findings from model wine studies.

This study highlights the dual role of closures in managing oxygen ingress and volatile compound retention. Low-permeability closures can help preserve DMS in wines where it enhances aromatic complexity, while higher-permeability closures might mitigate reductive off-flavors in wines prone to sulfur compounds. These findings may account for the reductive notes empirically observed in red wines sealed with highly impermeable closures compared to those bottled with more permeable alternatives. The latter could be advantageous by facilitating the permeation of light volatile sulfur compounds, such as H₂S, MeSH, or EtSH.

References

[1] Segurel, M. A., et al. (2004). Journal of Agricultural and Food Chemistry 52(23): 7084-7093.

[2] Loscos, N., et al. (2008). Analytica Chimica Acta 621(1): 24-29.