The Scientific Reason Canned Wine Can Smell Like Rotten Eggs

Although bottles of wine are a dinner party necessity, they aren't always practical for portable sipping. Canned wine eases the burden of lugging around 750 milliliters of pinot grigio while still delivering the flavor and fun of your favorite vino variety. But, if you've ever opened a can of wine expecting a fresh, fruity, and fabulously funky smell only to be greeted with the eye-watering aroma of rotten eggs, you're not alone. The scent is a relatively common occurrence. Thanks to researchers at Cornell University, we now know why your canned cabernet smells less like black currant and more like boiled eggs.

Sulfur dioxide (SO2), colloquially known as sulfites, is a chemical compound found in almost all wine. SO2 is a natural byproduct of the fermentation process, and more is often added to preserve the flavor, color, and overall quality of wine. When SO2 interacts with the aluminum in cans, it transforms into hydrogen sulfide (H2S), leading to the smell of rotten eggs. Although the interior of aluminum cans is veiled with plastic to prevent metallic taste, corrosion, and that sewage-marinated egg smell, the coating doesn't always inhibit the interaction.

Aroma plays a foundational role in how we perceive taste, which means stinky wine doesn't just agitate the nose, but the tastebuds, too. So, how can we prevent, or fix, the dreaded rotten egg smell and foul flavor? It starts at the top with wine manufacturers. The Cornell researchers suggest ditching the interior plastic coating for epoxy, which reduces the formation of H2S. They also determined that keeping SO2 at four-tenths parts per million, when combined with the epoxy coating, significantly reduces the chances of H2S developing.

While we wait for wine manufacturers to improve their canning materials and adjust their wine-to-SO2 ratios, shopping smart can reduce the likelihood of stinky canned wine. Opt for natural wines, which typically don't include added sulfites and instead rely solely on those that occur, well, naturally. If you can't find natural canned wine, select a canned red over a white — they have lower SO2 quantities and are generally less likely to stink. If you do happen to crack open a smelly can of wine, pour it into a glass and swirl it around to aerate the drink and evaporate H2S.