Thanks for the note on sulfur dioxide - but what are sulfates? Had an Ontario wine recently that gave me a tremendous headache and I saw (too late) on the label that it contained sulfates. Are wineries obliged to indicate sulfates on the label? Juudy
Answer From Expert Roger Bohmrich MW
Sulfates and sulfites are not the same chemically although they are easily confused. The statement on a wine bottle would be "contains sulfites," which is mandatory on wines sold in the U.S. containing over 10 ppm. Sulfites occur naturally as a result of alcoholic fermentation, and they are also added at all stages of production from the grape to the finished wine at bottling. In fact, sulfites in various forms are the most common additive in wine around the world and have been used since ancient times. There are many possible causes of wine headaches, and some are not yet fully understood. However, the prevailing scientific opinion is that sulfites are not one of the causes.
