For nearly 35 years Cathy Corison, founder of Corison Winery, has looked out over her Napa Valley vineyard with pride. Her vineyard has been free of pesticides for years. She uses cover crops to add nitrogen to the soil. When destructive leafhoppers appeared in her vineyard, she sprayed her vines with mineral oil instead of chemicals to kill the larvae. The vines yield a mere one to one and a half tons of grapes per acre, but wine enthusiasts claim they produce unparalleled fruit and stunning wines. Corison’s commitment has always been to quality over quantity. But even though she farms organically and employs sustainable agriculture practices, Corison wines are not certified organic. One reason is she adds sulfites to her wines.
Sulfites are a naturally occurring class of compounds and they’re everywhere: most living organisms, including humans, produce sulfites. Our bodies produce about 1,000 mg of sulfites each day—a level that’s 100 times higher than the amount in your average glass of red wine. In our bodies, sulfites act as antioxidants—scavenging the free radicals that damage cells. They serve a similar function in food and wine, preventing the chemical reactions that cause off flavors to develop. And the fact is, even if a winemaker doesn’t add sulfites to a wine, some sulfites are created naturally during the winemaking process.
So why aren’t sulfites allowed in certified organic wines? “When the USDA was developing standards for certified organic wine, a few winemakers who were already making wines without adding sulfites lobbied to keep added sulfites out of certified organic wine,” says Glenn McGourty, M.S., a University of California Cooperative Extension winegrowing and plant scienceadvisor. Their argument was that organic foods shouldn’t contain added preservatives. And they won. While some winemakers were creating wines specifically for the less than 1 percent of the U.S. population with sulfite allergies, others believe adding sulfites hides the wine’s delicate flavors and its terroir—the authenticity and sense of place you can taste in a wine. “Adding sulfites to wine can mask subtle flavors that would’ve otherwise added to the natural bouquet of the wine,” says Paul Frey of certified organic Frey Winery in Mendocino, California.
Corison agrees that using too many sulfites can negatively affect a wine’s flavor. But she, like many other winemakers, argues that it’s impossible to make premium wines without using any added sulfites. (In fact only about 1 percent of wine sold worldwide is certified organic.) Sulfites are added to suppress wild yeasts and bacteria and minimize byproducts of chemical reactions, all things that can lead to off flavors. Corison uses only as many sulfites as she needs and as a result, her wines have only 50 parts per million of total sulfites at bottling (the upper limit is 350 ppm), 20 of which are produced naturally by the yeast (most wines contain 25 to 150 ppm). Just adding this small amount of sulfites helps to preserve the fruity character of Corison’s wines. Sulfites also slow the oxidation process, helping to preserve wine’s flavor as it ages. Organic wines with no added sulfites age unpredictably, notes McGourty. “The downside to not using sulfites is that those wines are notoriously unstable over time.”
There is an alternative for consumers who aren’t concerned about sulfites but who are concerned about the environment. Look for wines labeled “made with organic grapes.” These wines are made with grapes grown according to certified organic standards and processed in certified organic facilities. “Sulfites are allowed in these wines, and their quality is much better overall,” says McGourty.
Amy Bieber, M.S., M.P.H., is a freelance writer in Temecula, California, and a frequent contributor to EatingWell.