Few words in the wine world carry as much confusion and anxiety as "sulfites." That small line on the back of every wine label — "Contains Sulfites" — has launched a thousand misunderstandings. Sulfites have been blamed for headaches, for hangovers, for allergic reactions, and for ruining what would otherwise be a perfect natural product. Some of these claims are true. Most of them are not. Here is what you actually need to know.
What Sulfites Actually Are
Sulfites — more precisely, sulfur dioxide (SO2) — are chemical compounds that occur naturally in many foods and are also widely used as preservatives. In winemaking, sulfur dioxide serves two critical functions: it acts as an antioxidant, preventing the wine from turning brown and losing its fresh flavors, and it acts as an antimicrobial agent, inhibiting the growth of unwanted bacteria and wild yeasts that could spoil the wine.
Here is something that surprises most people: every wine contains sulfites, even wines labeled "no sulfites added." This is because yeast naturally produces sulfur dioxide during fermentation. The amount varies, but it is typically between six and forty parts per million. What most people are concerned about is the additional sulfur dioxide that winemakers add after fermentation to stabilize the wine for aging and shipping.
Total sulfite levels in wine generally range from about ten parts per million in some natural wines to around two hundred parts per million in sweet white wines, which need more protection because residual sugar makes them more vulnerable to microbial activity. For context, dried fruits like apricots can contain up to two thousand parts per million of sulfites — roughly ten times the maximum allowed in wine. If you can eat dried apricots without issues, sulfites in wine are very unlikely to be your problem.
Why Winemakers Add Sulfites
The use of sulfur in winemaking is ancient. Roman winemakers burned sulfur candles inside their amphorae before filling them with wine. Dutch traders in the seventeenth century added sulfur to barrels of wine being shipped to England. The practice has persisted for a simple reason: without adequate sulfite protection, most wines deteriorate rapidly.
An unprotected wine exposed to oxygen begins a cascade of chemical reactions. Fresh fruit aromas fade. The color shifts from vibrant to dull. Acetaldehyde accumulates, giving the wine a bruised-apple character. In the worst case, acetobacter bacteria convert the alcohol to acetic acid, literally turning the wine into vinegar. A small amount of sulfur dioxide arrests all of these processes, which is why the vast majority of winemakers — including most organic producers — use it.
The amount added depends on the wine style. Red wines generally need less because their tannins provide natural antioxidant protection. Dry white wines need a moderate amount. Sweet wines need the most because residual sugar creates a more hospitable environment for microbes. A well-made dry red wine might contain fifty to eighty parts per million total sulfites, while a dessert wine might contain one hundred fifty or more.
Sulfite Sensitivity: Who Is Actually Affected
True sulfite sensitivity exists, but it is far less common than popular belief suggests. The best clinical data indicates that roughly one percent of the general population has a measurable sensitivity to sulfites. Among people with asthma, the number is higher — approximately five to ten percent of asthmatic individuals may experience sulfite-triggered symptoms.
The symptoms of genuine sulfite sensitivity are primarily respiratory. They include wheezing, chest tightness, coughing, and in rare cases, anaphylaxis. Hives and skin flushing can also occur. Notably, headaches are not a primary symptom of sulfite sensitivity. The widespread belief that sulfites cause wine headaches is one of the most persistent myths in wine culture. If your main symptom after drinking wine is a headache, sulfites are almost certainly not the cause — histamines and tannins are far more likely culprits.
If you do suspect a genuine sulfite sensitivity, the most informative test is to compare your reaction to wine with your reaction to other high-sulfite foods. Dried fruits, pickled vegetables, deli meats, bottled lemon juice, and shrimp all contain significant sulfites. If you react to all of these foods, sulfite sensitivity is worth discussing with an allergist. If wine is the only thing that bothers you, the cause is almost certainly something else — and our palate quiz can help you identify what that something else might be.
Finding Lower-Sulfite Wines
Even if sulfites are not your trigger, there are good reasons to seek out wines with lower sulfite levels. Many wine lovers report that low-sulfite wines simply taste more alive — more expressive, more textured, more connected to a sense of place. Whether this is because of the lower sulfites themselves or because low-intervention winemaking tends to produce more interesting wines is an open question. Either way, here are the categories to explore.
Red wines over whites. As mentioned, red wines generally have lower total sulfite levels than white wines because tannins provide natural protection against oxidation. If you are trying to minimize sulfite intake, choosing reds is a simple first step.
Dry wines over sweet. Sweet wines require more sulfite protection. A bone-dry wine will almost always contain less SO2 than a wine with residual sugar.
Organic and biodynamic wines. In the United States, wines certified as "organic" cannot have any added sulfites, though they still contain naturally occurring ones. Wines labeled "made with organic grapes" may contain added sulfites but are held to lower maximums than conventional wines. European organic certifications allow moderate sulfite additions but at lower levels than non-organic wines.
Natural wines. The natural wine movement embraces minimal or zero added sulfites as a core principle. Many natural winemakers add no sulfur dioxide at all, or just a tiny amount at bottling. These wines can be extraordinary — vibrant, alive, completely unique — but they require more careful handling and storage. Read more about this in our guide to what natural wine actually means.
The Natural Wine Connection
The sulfite conversation is inseparable from the rise of natural wine. For many natural wine advocates, sulfites represent everything they reject about conventional winemaking — chemical intervention, standardization, the erasure of terroir. There is philosophical merit to this position. A wine made with no added sulfites is, by definition, a more transparent expression of the grapes, the vineyard, and the vintage.
But the conversation can become ideological in ways that obscure the science. A moderate amount of sulfur dioxide, skillfully applied, does not mask terroir. It protects it. Many of the world's greatest wines — including Grand Cru Burgundy, first-growth Bordeaux, and top Barolo — use judicious sulfite additions and age magnificently for decades. Meanwhile, some zero-sulfite wines can be brilliant, and others can be oxidized, volatile, and frankly unpleasant.
The wisest approach is pragmatic rather than dogmatic. If you feel better drinking low-sulfite or no-added-sulfite wines, trust your experience. If you love a conventionally made wine and feel perfectly fine drinking it, enjoy it without guilt. The goal is not to eliminate sulfites from your life but to understand what they are, what they do, and whether they actually affect how you feel.
Practical Takeaways
If you are trying to understand your own relationship with sulfites, here is a clear path forward. First, test against other sulfite-rich foods to determine if you have a true sensitivity. Second, if wine is the only thing that bothers you, explore other causes — histamines, tannins, alcohol level, and dehydration are all more common triggers for headaches and flushing.
Third, if you want to explore lower-sulfite wines, start with dry reds from organic or natural producers. Use our wine scanner to check estimated sulfite levels before you buy. Keep a log of what you drink and how you feel — pattern recognition is the most powerful diagnostic tool you have.
The "Contains Sulfites" label exists because United States federal law requires it on any wine with more than ten parts per million of sulfites. It tells you nothing about how much sulfite the wine actually contains, nothing about whether the amount is high or low for the style, and nothing about whether it will affect you personally. Context is everything. And context is exactly what Somm is designed to give you.