Dimethyl sulfide transfers through closure during accelerated model wine ageing: proof-of-concept & prospects

Dimethyl sulfide (DMS) is a volatile sulfur compound that plays a complex role in wine aroma, contributing both positive and negative sensory attributes depending on its concentration. While DMS is known to accumulate during bottle aging through the degradation of precursors such as <i>S</i>-methylmethionine (SMM), this study presents the first evidence that DMS can also be lost through wine closures <i>via</i> a permeation mechanism. In practice, the permeation of DMS through closures was demonstrated using model wines spiked with DMS and aged under accelerated conditions at 35 °C. As DMS was detected only in the ®Tenax tubes placed above bottles containing the spiked model wines, we formally proved that DMS can permeate closures under these conditions and may account for 12 % of initial DMS. In Syrah wines, DMS concentrations increased during bottle aging due to the breakdown of SMM. However, wines sealed with more permeable closures exhibited lower DMS levels compared to those sealed with low-permeability closures, supporting findings from the model wine studies. This previously unreported phenomenon of permeation underscores the significant influence of closure permeability on the aromatic evolution of aged wines.