Nearly 3,000 years ago, winemakers in Ancient Greece made a discovery. If they took gypsum—a chalky white mineral rich in sulfur—and mixed it with their wine before fermentation, the wine would keep for years without spoiling.
Those growers were the first to adopt one of winemaking’s most enduring practices: preserving wine with sulfites.
Today, almost every wine in the world contains sulfites—and for some people, that causes concern. Are sulfites bad for you? Do they cause headaches or health problems? And if they are okay, why do wine bottles have “contains sulfites” listed on the label?
Let’s talk about sulfites in wine, the health effects of sulfites, why most wine labels have to include “contains sulfites,” and whether or not you should look for sulfite-free wine.
What Are Sulfites?
“Sulfite” is another word for sulfur dioxide, an antioxidant that keeps wine fresh.
Wine is fragile while it’s fermenting, and it’s easy for young wines to spoil in the bottle. Sulfites do two things: [*]
- Kill bacteria that make wine go bad.
- Stop trapped oxygen from turning bottled wine brown.
Virtually every wine in the world contains small amounts of sulfites. [*] Sulfur dioxide is a natural byproduct of fermentation, so even wines with no added sulfites (like many organic and biodynamic wines) still have sulfites in them, and must list “contains sulfites” on their labels.
Without sulfites, most wine wouldn’t last longer than six months. With sulfites, wine keeps for years, or even decades. For that reason, winemakers (including natural winemakers) often add extra sulfites to their wine.
Are Sulfites in Wine Bad for You?
Sulfites often take the blame for causing wine hangovers. However, research shows that for 99% of people, sulfites cause no headaches or health problems. [*]
Roughly 1% of the population is sensitive to sulfites. If you have asthma, your risk of sulfite sensitivity rises to 3-10%. [*]
If you are sensitive to sulfites, consuming them may cause headaches, [*] digestive issues, [*] rashes, [*] and, in rare cases, trouble breathing. [*]
When it comes to sensitivity, the amount of sulfites also matters. Any wine with more than 10 parts per million (ppm) must have “contains sulfites” on the label. [*] However, 10 ppm is an extremely small amount of sulfites, and is unlikely to cause a reaction. [*]
In the US, conventional wines can contain up to 350 ppm, while organic wine can have up to 100 ppm. [*] Those are much higher numbers, and are more likely to trigger a sulfite sensitivity. [*]
How to Tell If You’re Sensitive to Sulfites
Sulfites are in a lot of common foods, often in much greater quantities than the sulfites in wine. If you have a sulfite sensitivity, you’d react to a variety of foods, including: [*]
- Dried fruit
- Pre-cut fruit
- Pickled food
- Jams and jellies
- Maple syrup
- BreadPizza
- Ground meat
- Lettuce
- Crustaceans (shrimp, crab, and lobster)
If you can eat the above foods without issue, you probably don’t have a sulfite sensitivity. That doesn’t mean the headaches you get from wine aren’t real—only that something else is likely causing them, like residual sugar or high alcohol.
But if sulfites are harmless, why do wine bottles have to have “contains sulfites” on their labels?
Sulfite labeling is for that 1% of the population with a sulfite sensitivity. The Food and Drug Administration (FDA) discovered sulfite sensitivity in the 1980s, and began requiring a “contains sulfites” label in 1988, to keep those few people safe. [*]
Are Sulfites Higher in Red or White Wines?
White wines often have more sulfites than red wines.
Red wines get their color from extended contact with grape skins during fermentation. Grape skins contain tannins, polyphenols, and other antioxidants that keep wine from spoiling. [*]
White wines have no skin contact during fermentation. They contain fewer natural antioxidants during early fermentation, leaving them more prone to spoilage. Many winemakers add extra sulfites to white wines to keep them from going bad as they ferment.
All that said, sulfites in wine are generally safe. If you have a reaction to wine, it’s more likely because of other things: high alcohol content, high residual sugar content, histamines, or possibly a combination of unlabeled wine additives.
If Sulfites are Safe, Why Avoid Them?
From a health perspective, sulfites in wine are fine for 99% of people. But from a winemaking perspective, sulfites matter a great deal.
Sulfites are strong sterilizers. They kill off bacteria and yeasts, which makes winemaking considerably easier. But according to many winemakers, that sterilization also destroys other, subtler aspects of wine, like terroir. They claim heavily sulfited wines are often flat or lack the delicate nuances that low-sulfite wines preserve.
Sulfites in Natural Wine
As a rule, natural winemakers keep sulfite use to a bare minimum, or add no sulfites at all. Many natural wines contain fewer than 10 ppm sulfites—a range that is less likely to cause headaches in sensitive people. [*]
Sulfites are generally safe, but if you want to avoid them, natural wines are often a good choice.
