Rachel Allison,* Austin Montgomery, and Gavin Sacks
*Cornell University, 411 Tower Rd., Stocking Hall, Room 253, Ithaca, NY 14853 (rba55@cornell.edu)

Sulfur-like off-aromas (SLOs), also called “reduced aromas,” are reportedly responsible for upwards of 25% of faults identified in premium wines. Hydrogen sulfide (H2S; “rotten egg” aroma) is often in excess of its sensory threshold (~1 µg/L) in wines with SLOs. A growing area of concern for H2S in packaged wines is in the fast-growing category of canned wines. This phenomenon is credited to reaction of SO2 in wine with aluminum metal and may occur even in the presence of a polymeric liner to prevent direct contact between aluminum metal and the wine. However, considerable variation is observed in H2S production among canned wines with similar free SO2 concentrations, such that predicting the suitability of a given wine for canning is still challenging. We report on the development and validation of an accelerated bench- test to predict H2S formation during canned wine storage. In the assay, a 1 × 2 cm coupon of coated Al is incubated in 25 mL wine under anoxic conditions and elevated temperatures. In initial experiments, 10 commercial wines were incubated with Al coupons coated with one of three different commercial polymeric liners. After three days at 50°C, there was negligible formation of H2S in red wines (<10 µg/L) and 15 to 200 µg/L H2S in white and rosé wines. Variation in H2S formation among wines far exceeded variation for replicate samples (average relative standard deviation <30%). Validation against canned wines stored at room temperature for up to eight months is currently underway.

Funding Support: New York Wine and Grape Foundation