Drinkers blame sulfites and red wine for a range of health problems, including breathing difficulties, allergic symptoms, and headaches, but the jury is still out on whether sulfur is actually the culprit. Histamines, which are produced by yeast and bacteria, and tyramine, an organic compound in red wine, have also been cited as possible causes. It is also interesting to note that white wine generally has more sulfites than red, yet this is associated with red wine. Other foods we eat have far higher sulfite levels than what naturally occurs in wine, so logically, sulfites are likely not the actual cause.
The use of sulfur dioxide in the wine making process has been spotlighted as causing health problems, although the scientific community is divided on the issue. Sulfur dioxide (SO2) — in the form of potassium metabisulfite — is added to most wines and many other food products for its antimicrobial and antioxidant properties. The term “sulfites” on wine labels refers mainly to sulfur dioxide, but also includes sulfurous acid and other sulfites. Sulfur dioxide is also a natural by-product of fermentation, so it is unlikely an SO2-free wine could ever be produced. Most yeast strains yield 10–20 milligrams per liter of SO2 during fermentation, although some, such as FX10 and M69, produce significantly more than others. Without sulfur, wine is prone to oxidation and spoilage.
Consumers have been asking questions since wine labels started to carry a “contains sulfites” message. Although a small number of drinkers suffer ill effects from sulfites, sulfites may be unfairly maligned. Having a warning on the label facilitates blaming any negative experience on the sulfites. That prompted a Colorado State University study of consumer perceptions of sulfites and whether drinkers would pay more for a bottle labeled “low in sulfur.”
The American Association of Wine Economists published findings that consumers would be willing to pay a little extra for wines that contain low levels of sulfites. About 64 cents to be precise— In comparison, the premium placed on organic wine is $1.22 — nearly double. Consumers are aware that “organic production protocol prohibits, among other things, the use of added sulfites.” In other words, if drinkers pay the extra for organic wine, low sulfites will be included in the package.
In this case, perception is everything. The Colorado study found drinkers believe sulfites to be the main cause of their wine headaches. Almost two-thirds of the study sample who suffered headaches believed sulfites were responsible. The study also revealed that those who do get a headache after a glass or two of wine are willing to pay as much as $1.23 extra for a low-sulfite bottle. Those who don’t generally have headaches are willing to pay 33 cents extra. Researchers worked hard to identify those who simply had a hangover, focusing on those who reported headaches after small amounts of wine. More than one-third of the study sample had experienced headaches from very little wine.
Less surprising was that the sulfite content of wines was not high on the list when it came to purchasing. People may prefer a low-sulfite wine, but it’s apparently not a priority. Researchers say quality and price are the two most important factors for wine buyers in the United States.