Jessica Green can usually tell when a new article about sulfites is published without opening a magazine or looking at her phone.
“In the last two months, I’ve been getting so many people coming in saying they have allergies,” says Green, owner of Down the Rabbit Hole, a natural wine store in Sayville, New York.
Wine labels rarely list ingredients, but the words “contains sulfites” are often prominent. The federal government requires bottles to carry a sulfite statement if a wine contains just 10 parts per million (ppm) of sulfites.
“That’s the only ingredient people see, and they automatically assume it’s giving them a headache,” says Green.
According to WebMD, a beacon of self-diagnoses, only 1% of the population has a sulfite sensitivity. People with asthma are at greater risk, but the Cleveland Clinic reports that just 1–2.5% of asthmatics have sensitivity to sulfites.
So, why are so many wine drinkers concerned with sulfites?
Sulfites are trendy right now, just like malolactic fermentation was in the 1990s, says Matthew Rorick, vigneron at Forlorn Hope Wines in Napa, California.
“It’s one of these soundbites or hot button phrases that people learn and say, ‘I only drink wine without sulfites,’ without understanding what sulfites do for the wine,” he says. “There’s this perception in the market that using sulfites is cheating somehow, or is doing some sort of industrial intervention.”
Rorick uses native yeasts to ferment grapes like Trousseau and Barbera, and the resulting wines are unfiltered and brimming with personality. But he’ll also use small amounts of sulfur dioxide, a liquid solution with sulfites, to prevent oxidation or limit bacterial growth as needed.
Sulfites are an important and mostly benign tool, he says. They’re just misunderstood.
“There’s this perception in the market that using sulfites is cheating somehow, or is doing some sort of industrial intervention.”—Matthew Rorick, Forlorn Hope Wines
Elemental sulfur occurs naturally and is found in every cell of the human body. Winemakers at certified organic vineyards often use it to control mildew. Sulfur is also present in sulfites, the inorganic salts that develop naturally during fermentation.
As a result, all wine contains sulfites. Some bottles just have added sulfites, too.
During fermentation, Saccharomyces yeast, a sugar-loving strain which is also used to make bread and beer, eats the sugar in the grape juice and converts it to alcohol. But these aren’t the only microbes that fight for the sugar, says Steve Matthiasson, winemaker and cofounder of Matthiasson Wines, who leans toward low-intervention processes.
Bacteria that can cause wine to smell like nail-polish remover or vinegar want to feed on the sugar, too. Yeast releases sulfites to thwart the bacteria. If all goes well, the yeast wins, and the wine ferments as expected. Other times, if a bacteria is taking over, a winemaker might add a little sulfur dioxide to help the yeast.
Some wines, like Matthiasson’s skin-fermented Ribolla Gialla, don’t need any sulfites.
“That wine is really high acid and crisp, and has a fair amount of tannin,” he says. “It’s much juicier and more giving without the sulfites.” However, he adds that his rosé retains its “crunchy, sort of fresh-fruit character” better with a little sulfur.
“We’re not adding a bunch of weird shit to our wine, but we use sulfites if I think it will make the wine better,” he says. “We’re trying to make wine we’re proud of.”
John Skupny, cofounder and winemaker at Lang & Reed, adds a little sulfur dioxide when the winery’s Chenin Blancs and Cabernet Francs need it. There’s a quirky bacteria that causes a mousy aroma, he says, and it can emerge just after malolactic fermentation. “Just 10 [parts per million] of sulfur will kill it,” he says.
Every so often, someone will call Lang & Reed to ask if they add sulfur to their wines, says Skupny. Each bottled wine has 20 ppm to 30 ppm sulfites. But nobody wonders about sulfites in the pale-golden dried pear that’s a tasting amenity at the St. Helena winery, he notes.
“We’re not adding a bunch of weird shit to our wine, but we use sulfites if I think it will make the wine better. We’re trying to make wine we’re proud of.”—Steve Matthiasson, Matthiasson Wines
Sulfur dioxide is present in a lot of packaged foods. According to the USDA, dried apricots could contain more than 2000 ppm sulfur dioxide. Meanwhile, the standard amount of sulfites added to a bottle of biodynamic wine is only up to 100 ppm.
Sulfur dioxide also keeps frozen potatoes, pickles and shrimp from turning brown.
“Anything uber-processed is probably going to have some sulfites because the whole point is to preserve food,” says Kristin Kirkpatrick, a registered dietitian with Cleveland Clinic.
There’s no blood or saliva test to determine if people have sulfite sensitivity, says Kirkpatrick. Doctors give patients food with sulfites and wait for reactions like itching, hives or a scratchy throat.
Those sensations can also be caused by other things in wine, says Theresa Heredia, winemaker at Gary Farrell Winery in Healdsburg, California.
“Red wine has histamines and tannins,” she says. “Any of those can cause allergies.”
Andrew Waterhouse, a wine chemist at University of California at Davis, says there are no studies linking sulfites to headaches, though too much tannin or alcohol definitely can make your head throb.
Heredia, who spent a decade making biodynamic wine, says that picking grapes while they have higher acidity helps her keep bottlings under the biodynamic standard of 100 ppm.
Higher acidity and higher tannins help stabilize wines, which means they’re less likely to require sulfur dioxide, says Kurt Beitler of Bohème Wines. Beitler and his team blast used barrels with hot water and steam to remove any trace of acetic acid, which pushes wine toward vinegar.
Beitler says his winemaking starts in the vineyard with rigorous canopy management. He trims leaves and drops clusters to give vines better airflow, so the grapes don’t mildew in the vineyard.
“Bringing only clean fruit to the winery is critical,” he says. “With fewer enemies, we need fewer guns.”