I went to law school because my fragile grasp of chemistry and math foreclosed every other career choice, from being a doctor to working the till at Mr. Sub. Then I swung from law into wine writing because I realized that the Wine Spectator is consistently easier to get through than the Ontario Reports. The Short Cellar is now probing the problem of faulty wine, and alas this is leading me full-circle back to chemistry.
Last week’s column discussed how to nurse the most common wine fault, contamination with 2-4-6 Trichloroanisol (aka corked wine). This time, we delve into the malady known as “reductive wine.”
When a freshly opened bottle (particularly a white wine) smells like rotten eggs, swamp gas or cabbage, it’s because the wine contains harmless traces of a chemical called hydrogen sulphide (H2S). This sulphur compound will sometimes form in a fermenting wine as part of a natural chemical reaction called “reduction.” It doesn’t usually affect the taste, but it does make your wine stink.
Winemakers have a number of tools to get rid of this sulphur before bottling, such as fining the juice with a copper compound. Merely exposing the wine to a little air will often allow the chemical to disperse. Even after a reductive wine has left the winery, it’s not game over. Because corks admit a small amount of air, sometimes a reductive bottle can cure itself as it sits on the shelf.
I am a big fan of screw caps for most wines, but they have one serious drawback: they are so airtight that they give no chance for a reductive wine to gradually discharge its hydrogen sulphide through exposure to air. Screw caps are meant to preserve the fresh, fruity character of a wine, but they can capture the sulphurous stench just as effectively.
The next time you twist into a bottle of reductive wine, don’t panic. The easiest remedy is to decant the wine and let it breathe — with luck, the hydrogen sulphide will blow off on its own accord in 10-20 minutes. But if that doesn’t work, drop a clean, shiny penny into the decanter. Then make a wish that your wine will be healed.
The scientific theory behind this little piece of voodoo is that the copper in the coin reacts with the hydrogen sulphide in the wine, converting it into an odourless copper or silver sulphide. It’s not unlike certain French winemakers who stir the wine vats with copper pipes to cure H2S. By using the penny, in just a few minutes, your wine will recover its perfume and you can commence drinking. Thanks, Science!
Matthew Sullivan is a civil litigator in Toronto. He blogs weekly here on lawandstyle.ca. The Short Cellar column also appears in the print edition of Precedent. Matthew can be reached at matthew@lawandstyle.beta-site.ca. Follow along on Twitter: @shortcellar.
Photo by Catherine Bulinski