Sulfites in Wine: What They Actually Do

Sulfites keep wine from turning brown and going to vinegar, and for the large majority of people they are not what causes the headache. They are a preservative, they exist in every bottle of wine ever made whether anyone added them or not, and the label on the back is a legal disclosure rather than a warning.

This one has become folklore, and the folklore is costing people wine they would enjoy. So here is the plain version, without the scolding and without the health claims.

What are sulfites actually doing in wine?

Two jobs, both of them dull and both of them essential. Sulfur dioxide stops oxidation, which is what turns a wine brown and flat at the edges until it smells like bruised apple. And it holds back the wrong microbes, the ones that would happily turn your bottle into vinegar over a slow summer.

Without any sulfur at all, most wine would not survive the trip from the winery to your table in the condition the winemaker intended. That is not a marketing position. It is chemistry.

Is there such a thing as sulfite-free wine?

No, and this is the fact that clears up most of the confusion. Yeast produces sulfur dioxide on its own during fermentation. Every wine has some, including the ones marketed as natural, low-intervention, or made with nothing added. The honest label is "no sulfites added," and you will notice that is exactly what the careful producers print.

In the United States, any wine carrying 10 parts per million or more has to say "Contains Sulfites" on the label. Nearly all wine clears that line, which is why nearly all wine says it. The phrase tells you the threshold was crossed. It tells you nothing about the amount.

How much sulfite is in wine compared to other food?

Less than people assume, and dramatically less than in a few things sitting in most kitchens right now.

• Dried apricots and other dried fruit are typically the highest sulfite item in a normal pantry, carrying many times what you would get from a glass of wine.
• Sweet and white wines generally carry more added sulfur than dry reds, because sugar and low tannin both need more protection.
• Dry red wine generally carries the least added sulfur of the three, because tannin is itself an antioxidant and does part of the job.

If a bag of dried fruit has never bothered you, sulfites in wine are an unlikely culprit. That is not a diagnosis, and anyone with a real reaction should talk to a doctor rather than a wine shop. But it is a useful place to start thinking.

So why does red wine give me a headache?

Because sulfites are the wrong suspect and red wine is full of better ones. Alcohol itself dehydrates. Tannins, histamines, and the other compounds that come with red grape skins are all more commonly pointed at than sulfur. And red wine, the thing people most often blame for headaches, is the style that typically carries the least added sulfite of all.

That last point is the one worth sitting with. If sulfites caused wine headaches, sweet white wine would be the worst offender by a wide margin. Ask around and see whether that matches anybody's experience.

We took the full question apart in why wine gives you a headache, which is a more useful read than anything on a back label.

What should I actually buy if I am worried about it?

Start with dry reds, which is where added sulfur tends to be lowest. Herzog Lineage Cabernet Sauvignon at $19.99 is a straightforward, properly dry red and an easy place to begin. Psagot Sinai at $27.99 gives you more structure and more to think about for eight dollars more.

If you want to go further, Dalton Single Vineyard Cabernet Sauvignon Meron at $39.99 is a serious, tannic, single-vineyard red, exactly the kind of wine where the fruit and the structure do the preserving work. The rest of the red wine shelf runs the same direction.

The other half of the answer is far less glamorous. Drink water alongside, eat something, and slow down. Those three change more outcomes than any label ever has.

Does any of this affect kashrus?

No. Sulfur dioxide is a processing aid used across the wine world, and it has nothing to do with what makes a wine kosher. That question is about who handles the grapes and the wine and under whose supervision, which we covered in what makes wine kosher. Two entirely separate conversations that get tangled together more often than they should.

Frequently asked questions

Do organic wines have no sulfites?

They still have sulfites. Organic certification limits how much sulfur can be added, and in some regions bans adding it, but the sulfur produced naturally during fermentation is always there. "No sulfites added" and "sulfite free" are not the same claim, and only one of them is possible.

Are white wines higher in sulfites than reds?

Generally yes. Whites and especially sweet wines usually need more added sulfur, because they lack the tannin that helps protect red wine from oxidation. Sweet wines tend to sit highest of all.

How common is a real sulfite sensitivity?

Uncommon. It is a recognized sensitivity that affects a small share of people, most often presenting as respiratory symptoms rather than headaches, and it is more associated with asthma than with the general population. Anyone who suspects they have one should ask a doctor, not a sommelier.

Does decanting remove sulfites?

Barely, and not in a way you can rely on. Some sulfur dioxide does dissipate with air exposure, but the amount is small. Decanting is worth doing because it softens tannin and opens aroma, which are much better reasons.

Do sulfites make wine last longer once opened?

They help, but only so much. An open bottle is still oxidizing, sulfur or not, and the fix is the same as always. Recork it, refrigerate it, and drink it in the next few days.

Buy the bottle you actually want. The back label is a legal notice, not a verdict.