What Are Sulfites in Wine? (And Do They Cause Headaches?)

Sulfites are preservatives, mostly sulfur dioxide, that winemakers use to keep wine fresh and stop it from oxidizing or spoiling. Almost every wine contains them, and a small amount forms naturally during fermentation. Despite their reputation, sulfites are not what gives most people a wine headache.

What are sulfites, exactly?

Sulfites are a family of sulfur-based compounds, chiefly sulfur dioxide (SO2), used throughout the food world as preservatives. In wine they do two jobs: they slow oxidation, the same reaction that browns a cut apple and eventually turns wine to vinegar, and they hold back stray yeast and bacteria that would otherwise spoil it. In other words, they are what keeps a bottle tasting like the wine the maker intended rather than something flat and off.

Here is the part that surprises people: every wine contains some sulfites, whether or not the winemaker adds any. Yeast produces a little sulfur dioxide on its own during fermentation, typically in the range of 6 to 40 parts per million. So the idea of a completely sulfite-free wine is a myth. What varies is how much extra the winemaker chooses to add on top of that natural baseline, and that is a genuine winemaking decision rather than a health scandal.

Why winemakers add sulfites

Winemakers have used sulfur to protect wine since Roman times, when barrels were treated with burning sulfur candles before filling. The reason is simple: wine is a living thing that wants to keep changing, and left unprotected, most of it would oxidize and sour within a matter of weeks. A small, well-judged dose of sulfur dioxide buys the wine stability, so it can travel, age, and reach your glass tasting the way it did when it left the cellar.

It helps to know what “unprotected” actually tastes like. A wine that has oxidized loses its fresh fruit first, then takes on flat, bruised-apple and nutty, sherry-like notes, and finally slides toward vinegar as bacteria convert its alcohol to acetic acid. Sulfur dioxide is the main thing standing between a bright bottle and that decline. This is also why the amount matters in both directions: too little and the wine is fragile, too much and you can smell it as a faint struck-match sharpness on the first pour. Good winemaking is largely about using just enough and no more.

There is a real trade-off, though, and this is where the honest version of the story matters. Wines made with no added sulfites can be wonderful, but they are more fragile. They oxidize faster, vary more from bottle to bottle, and often need refrigeration and careful handling. Many natural wines lean this way on purpose, accepting a shorter, more unpredictable life in exchange for minimal intervention. If you want to understand that whole philosophy, our piece on what natural wine is covers it in depth. Neither approach is right or wrong; they are different priorities.

What “Contains sulfites” on the label means

In the United States, the Alcohol and Tobacco Tax and Trade Bureau requires any wine with 10 parts per million or more of sulfites to carry the phrase “Contains sulfites.” Since almost all commercial wine clears that threshold once you count the naturally occurring amount, that label is close to universal. It is a disclosure, not a warning that a particular bottle is unusually high. The European Union has a nearly identical rule at 10 milligrams per liter.

The legal ceilings are worth knowing, because they show how modest wine’s sulfite levels really are. US law caps total sulfur dioxide in wine at 350 ppm, and most dry table wine sits far below that. The rules also draw useful lines for shoppers:

• USDA Organic wine can have no sulfites added at all, only the naturally occurring amount.
• “Made with organic grapes” allows added sulfites up to 100 ppm total.
• Conventional wine can go higher, up to the 350 ppm cap, though most does not come close.

So a label that says “Contains sulfites” tells you almost nothing about whether a wine is high or low. It only tells you the wine is, like nearly all wine, above a very low legal line.

How much sulfite is actually in wine

This is where the headache myth starts to fall apart, because wine is nowhere near the biggest sulfite source in an ordinary diet. Dried fruit dwarfs it. A small serving of dried apricots can carry several times the sulfites of an entire bottle of wine, yet nobody blames a trail mix for their migraine. Here is how wine compares to some everyday foods:

Food or drink	Typical sulfite content (ppm)
Dried apricots	500 – 2,000
Other dried fruit (raisins, prunes)	500 – 1,000
Sweet or dessert wine	150 – 400
White wine	50 – 200
Red wine	30 – 150

Two things jump out. First, wine’s levels are ordinary by food standards. Second, and this is the detail that undoes the whole myth, red wine tends to have the least of all. Red wines carry a natural set of antioxidants in their tannins, which come from grape skins and seeds, so they need less added sulfur dioxide to stay stable. Sweet and white wines, which have little or no tannin to protect them, usually get more. Keep that ranking in mind for the next section, because it does not match the myth at all.

It is worth understanding why those numbers vary so much between styles. Sweetness is the biggest factor: any wine with leftover sugar is a target for stray yeast that would happily start fermenting again in the bottle, so sweet and dessert wines need the most sulfur dioxide to stay stable, which is why they top the list. White and rosé wines come next, since they lack the protective tannins of red. Bottling choices matter too, as wines meant to be shipped far and sit on shelves for a year often get a touch more than a bottle destined to be drunk locally and young. None of this makes a wine “high” in any meaningful health sense; it simply reflects what each style needs to survive the trip to your table.

Do sulfites cause headaches? The myth and the evidence

The belief that sulfites cause wine headaches took hold in the 1990s, right when that “Contains sulfites” label became mandatory in the US. People saw a new warning-like phrase on the bottle, connected it to a symptom they already had, and a durable piece of folklore was born. It is an understandable leap, but the evidence does not support it.

Genuine sulfite sensitivity is real, but rare. It affects roughly 1% of people, and shows up mostly in those with asthma. When it does, the reaction is respiratory: wheezing, chest tightness, sometimes hives. It is not a headache disorder. If sulfites triggered headaches, the people affected would be a small, specific group reacting with their lungs, not the broad population who report a throb after a glass of red.

Then there is the ranking problem. White and sweet wines contain more sulfites than red, and dried apricots contain far more than any wine, yet red wine is the drink singled out for headaches. A cause that is highest in the foods and wines least blamed, and lowest in the wine most blamed, is not a very convincing cause. That mismatch is the single clearest reason to look elsewhere.

So what actually causes red wine headaches?

The honest answer is that there is no one villain, which is exactly the kind of question AboutWine is built to reason through rather than reduce to a slogan. A red wine headache is most likely a combination of factors that vary from person to person:

• Quercetin. This is the most interesting recent lead. A 2023 team at UC Davis proposed that quercetin, a natural antioxidant concentrated in grape skins, can be converted in the body to a form that blocks ALDH2, the enzyme that clears acetaldehyde, a toxic byproduct of alcohol. When acetaldehyde builds up, you get headache, flushing, and nausea. Red wines have far more of these skin compounds than whites, which fits the pattern. Human trials are still ongoing, so treat it as a strong hypothesis, not settled fact.
• Histamines. Red wine has higher histamine levels than white, and people with a histamine intolerance may react to it with headaches or congestion.
• Tannins. A smaller group of people appear genuinely sensitive to tannins, the same compounds that give red wine its grip.
• Alcohol and dehydration. The simplest and most common driver of all. Alcohol is a diuretic, and dehydration alone causes headaches, red wine or not.
• Congeners and biogenic amines. Darker, more complex drinks carry more of these fermentation byproducts, which are linked to worse hangovers.

The useful takeaway is that “sulfites” was always too simple. Your headache is more likely some mix of your own body chemistry, how much you drank, whether you hydrated, and compounds that have nothing to do with the preservative on the label.

Should you seek out low-sulfite wine?

For most people, chasing “low-sulfite” or “no added sulfites” wine to prevent headaches is solving the wrong problem, since sulfites are very unlikely to be the cause. The people who genuinely benefit from watching sulfites are those with a diagnosed sensitivity or asthma, who already know to be careful with dried fruit and processed foods too.

That said, if you simply prefer wine with less added sulfur, you have real options. Dry red wines tend to sit at the low end naturally. Organic wines and many natural wines add little or none. Just go in knowing the trade-off from earlier: less added sulfur usually means a more delicate, shorter-lived wine that wants to be drunk young and stored well. That is also why sulfites matter for how long a bottle lasts after opening, since they are part of what slows oxidation once the cork is out.

How to drink wine with fewer headaches

If wine reliably gives you a headache, the label is the least useful place to look. A few practical habits do far more than hunting for a “sulfite-free” bottle:

• Drink water alongside it. A glass of water between glasses of wine offsets the dehydration that causes most of the ache.
• Eat while you drink. Food slows alcohol absorption and softens its effect.
• Test the “red wine” theory. Try a white or a rosé on another evening. If those don’t bother you but red does, your trigger is something in red specifically, like quercetin or histamines, not sulfites, which whites have more of.
• Pace yourself and notice your own pattern. The amount you drink and your own chemistry matter more than any single compound.

Treating it as an experiment you run on yourself beats trusting a myth printed on the back label. That is the whole idea behind understanding wine rather than reacting to it: once you know what sulfites actually do, you can stop worrying about the wrong thing and enjoy the glass.

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Frequently asked questions

Are sulfites in wine bad for you?

For the large majority of people, no. Sulfites are a common, regulated food preservative found in everything from dried fruit to packaged juice, and wine's levels are modest by comparison. Only about 1% of people have a genuine sulfite sensitivity, and it shows up mainly in those with asthma as respiratory symptoms like wheezing or tightness, not as headaches. If you can eat dried apricots or a handful of raisins without trouble, wine's much smaller dose of sulfites is very unlikely to be a problem for you.

Do sulfites cause red wine headaches?

Almost certainly not, for most people. The clearest clue is that white and sweet wines contain more sulfites than red wine, yet red is the one blamed for headaches. If sulfites were the trigger, whites and dessert wines would be worse. Recent research from UC Davis points instead to quercetin, a natural compound in grape skins that can interfere with how your body breaks down alcohol. Histamines, tannins, and plain dehydration all play a part too.

Is there such a thing as sulfite-free wine?

Not really. Even when a winemaker adds none at all, fermentation itself produces a small amount of sulfur dioxide naturally, usually somewhere between 6 and 40 parts per million. That is why careful labels say 'no added sulfites' rather than 'sulfite-free.' Wines made with no added sulfites do exist and can be excellent, but they tend to be more fragile and shorter-lived, since sulfites are part of what keeps wine stable.