Sulfur dioxide in wine is one of the most frequently discussed and yet simultaneously one of the most frequently misunderstood issues in winemaking.
"Contains sulfites" just doesn't sound right, especially considering many other things have far higher levels than wine—dried apricots, for instance, or commercial orange squash.
Briefly, sulfites are a group of sulfur compounds several of which are commonly used as preservatives, including sulfur dioxide and sodium metabisulfite. Sulfites help to protect wine from oxidization or from turning into vinegar, and most wines contain them as a permitted additive, usually added at bottling or at the end of fermentation.
In a tiny percentage of people, sulfites—even in minute quantities—can trigger an allergy-like reaction, and the risk of this is considerably higher for asthmatics. But adverse effects from wine, such as a runny nose and a sore head, can be due to a multitude of factors.
Anyone concerned about sulfites should look for "no added sulfites" on the wine label. One might also turn to natural wines, a movement begun in the 1980s by Beaujolais négociant Jules Chauvet, which attempts to use little or no sulfites.
Proponents of natural wine argue that sulfites freeze the wine in time.
(via The Wall Street Journal)
