Sulfur is a natural by-product of the wine making process and, as a result, there will always be around three to six parts per million (ppm) of naturally occurring sulfur in a wine. Today, wine makers often elect to add sulfur for a variety of reasons throughout the wine making process whether it be in the vineyard, in the wine room or in the cellar.
Why do wine makers add more sulfur? In the vineyard, sulfur can be used to combat pests and diseases. After harvest, it can be used to ensure a predictable fermentation or prolong the time before vinification by killing any yeasts or microbial life on the skins of the grapes. In the wine cellar, sulfur is commonly used to clean barrels and fermentation vats in preparation for harvest. It can be used in the cellar at the time of bottling (especially for export wines) to maintain a wine’s color and protect it from re-fermentation which produces a spritzy sensation on the palate.
How much sulfur are we talking about? In the European Union, the maximum sulfite level for certified biodynamic red wine is 60 ppm while the certified organic designation for red wine is limited to 90 ppm. White wines in both categories allow slightly higher levels. For conventional wines, the EU allows 160 ppm for red, 210 ppm for whites and rosés and 400 ppm for sweet wines. In the U.S., the limit is 350 ppm.
So, why does the level of sulfur matter? The common perception is that sulfites in wine (especially red wine) contribute to headaches. In fact, sulfites have been shown to affect a limited population of people (less than 1% of the population) with allergies to sulfites or asthmatic conditions. In addition, red wine tends to have the lowest level of sulfites amongst the wine styles. So, while many people do get headaches after drinking wine it appears unlikely that sulfites are the reason – or at least it’s unlikely they are the only reason. Even if sulfites are innocent in this regard, we find other good reasons to seek out wines that are lower in sulfites. (more…)