Winemaker's Journal - November 2011
Sulfites: Realities and Myths
Consumer questions are a great source of topics for this section, and one of the more popular ones is “do you use sulfites and are there any side effects?” The short answer is “yes, but only to a handful of people.” According to the University of Florida’s Institute of Food and Agricultural Sciences and other sources, the FDA estimates that only 1% of the population has sulfite sensitivities. Here is my take the subject from 30-plus years of winemaking, and I recommend that you seek medical advice if you have any concerns.
Winemakers have been using sulfites to prevent spoilage for thousands of years, but the practice became more prevalent in the late 1800s. Primary references are difficult to find, but sulfites are mention in several works about ancient winemaking including William Patton’s Bible Wines, T. S. Carr’s Roman Antiquities, and Samuele Bacchiocchi’s Wine in the Bible.
What are sulfites and why do winemakers use them?
Sulfites are inorganic salts that prevent spoilage (microorganisms and oxidation) and discoloration in foods and beverages. They are used to preserve the freshness of white wine and promote the longevity of red wine.
- European wines don’t contain sulfites.
Sulfites are used worldwide except for the few vintners making organic wines, but label warnings are only required in the US and Australia.
- Sulfites cause headaches.
Wine headaches are suspected of being triggered by several factors (histamines, tannins, prostaglandins, tyramine and alcohol), but sulfites are not one of the known causes.
- Sulfites are only used in wine, and/or sulfites are only added to red wine.
Sulfites may be added to prevent spoilage in foods such as dried fruits, seafood, baked goods, juices, mayonnaise and guacamole, but companies are only required to list them if the finished product contains more than 10 parts per million (ppm). Sulfites are used to make white wine.
- If a wine contains sulfites, then they must have been added.
Several sources including about.com indicate that yeasts naturally generate sulfites during fermentation (over 20 ppm by some estimates).
- High-quality barrel-aged wine can be made without adding sulfites.
Wines bottled shortly after fermentation can be made with no, or very low levels of, added sulfites. By nature, however, aging wine in barrels requires a stabilizing agent (e.g. brandy was first added to Port in the 1700s to prevent spoilage), and sulfites are the most effective means of stabilization during long-term aging (8–30 months).
- Domestic wines containing more than 10 ppm of sulfites must bear a “contains sulfites” warning on the label.
- The maximum concentration of sulfites allowed in wine is 350 ppm.
Notes: organic wines must be made with organic grapes and no added sulfites, but they may still contain less than 10 ppm of naturally occurring sulfites. It is estimated that non-organic wines contain 25–150 ppm of sulfites.
It is important to remember that thousands of winemakers around the world drink wines containing traces of sulfites daily, and we serve them to our family and friends knowing they are safe to consume. Sulfites are an indispensable tool in winemaking, and at this juncture, there are no comparable methods of creating world-class, age-worthy wines without them.