Sulfites - Why are they in my Wine?
Over the past several weeks, the subject of preservatives in wines has been raised several times during tastings at 4.0 Cellars. By far, the most common and important preservative used for and found in wines are sulfites. The sulfite ion is an effective antioxidant, and is used to help preserve numerous prepared food products. It has been some time since last writing on this subject, but since there remain many questions about sulfites, as well as many misconceptions, this edition of Carl’s Corner is focused on sulfites and their key role in the wine industry.
The sulfite ion is an effective antioxidant that helps protect wine by being sacrificially oxidized by oxygen (in air) and some oxidative organisms in the winemaking process. This protects the wine itself from being oxidized. Oxidation of wine will result in browning of the color, loss of fruit aromas and flavors, and development of acetic acid (vinegar) characteristics.
Most wines contain added Sulfite at very low levels not detectable by or bothersome to most people. Winemakers adjust sulfite levels, based on acidity or pH of the wine, to protect their products from oxidation as the wine is aged, bottled, stored, shipped and eventually consumed. Because white wines are more susceptible to oxidation, they typically contain a higher concentration of sulfite ion (50-100 ppm) than red wines (30-60 ppm).
Those “natural” or “No Added Sulfite” wines are particularly susceptible to oxidative spoilage, and typically must be consumed sooner rather than later. For these wines, oxidation becomes a ticking time-bomb as the already low sulfite levels decrease over time. All wines contain some measure of sulfites that are generated in the natural process of fermentation. Modern commercial yeasts used in wine fermentation produce small amounts of sulfite (10-20 ppm). Some winemakers prefer to use natural or indigenous yeasts, those that naturally occur on the grapes or in the winery itself. These indigenous yeasts can actually create even greater levels (20-100 ppm) of sulfite ion in wines.
Only about 1 in 1,000 people have a sulfite allergy, and this medical issue is typically well-known long before the person reaches drinking age. Many common foods, like dried fruits, legumes, frozen fruits & vegetables (French fries), etc., contain added sulfites as antioxidants. If you can eat a dried apricot with no ill effects, it is highly unlikely you have an allergy triggered by sulfites.
The most common misconception about sulfites in wine is that they cause headaches. This prevalent wine myth receives no support from numerous medical studies. Some claim sulfites in red wines cause headaches, while white wines are OK. If sulfites were the culprit, white wines should be worse as they tend to have higher levels of added sulfites for greater protection against oxidation. So, do sulfites cause headaches? The simple answer is NO.
If not sulfites, then what do we blame for those sometimes painful mornings after drinking wine. Medical researchers have proposed three possible culprits: 1) allergic reaction to naturally occurring biogenic amines, like histamines; 2) tannins, found mostly in red wines, which are known to release serotonin, a chemical that can cause constriction of blood vessels; and 3) good ol’ ethyl alcohol that promotes cellular dehydration and constriction of blood vessels, which, in turn, WILL result in headaches. If headaches are a problem, the best recommendation is to drink LOTS of WATER while consuming wine, or other alcoholic beverages, and perhaps consume a bit less alcohol.
The information provided above has been adapted from a number of reliable published sources. The following source was particularly helpful in preparing this Carl’s Corner edition.
“Top 10 Winemaking Myths, The facts, the myths, and the quackeries” by Daniel Pambianchi, WINEMAKER, June-July 2014, p 31