Sulfites show up in a wide range of foods and drinks, from dried apricots and wine to frozen french fries and shrimp. They occur naturally in some foods through fermentation and are added deliberately to many others as preservatives that prevent browning, kill bacteria, and extend shelf life. Knowing where they hide matters most if you’re among the 3 to 10% of people with asthma who experience sulfite sensitivity, though anyone trying to reduce their intake benefits from understanding the full picture.
Foods With the Highest Sulfite Levels
Dried fruits top the list. Manufacturers treat them with sulfur dioxide to preserve color and prevent spoilage, and the concentrations can be remarkably high. Dried apricots average around 1,554 mg/kg of sulfur dioxide. Dried apple varies even more wildly, ranging from 522 to 2,060 mg/kg depending on the brand and processing method. By contrast, sultanas (golden raisins) contain very little, typically under 10 mg/kg, because they’re processed differently.
That gap between dried apricots and sultanas illustrates an important point: you can’t assume all dried fruits carry the same sulfite load. If a dried fruit looks unusually vibrant (bright orange apricots, for instance), sulfites are almost certainly responsible. Darker, more naturally colored versions tend to be untreated or lightly treated.
Wine, Beer, and Other Drinks
Wine is the food most commonly associated with sulfites, and for good reason. Sulfites form naturally during fermentation and are also added by winemakers to stabilize the final product. Levels range from about 5 ppm to 200 ppm across the spectrum. Red wine sits on the lower end, typically around 50 to 75 mg/L for a dry red, while dry white wine tends to run higher at around 100 mg/L. Sweet wines generally contain the most, since more sulfite is needed to prevent residual sugar from refermenting.
Beer also contains sulfites, though usually at lower levels than wine. Other beverages to be aware of include bottled lemon and lime juice, grape juice, and fruit-flavored cordials.
Shrimp, Lobster, and Shellfish
Fresh shrimp and other crustaceans are routinely dipped in a sodium metabisulfite solution shortly after harvest. The reason is cosmetic as much as practical: without treatment, shrimp develop dark spots on their shells (called melanosis or “black spot”) within hours. The discoloration is harmless but makes the product look unappealing and unsellable. To prevent it, batches of roughly 500 shrimp are immersed in a sulfite solution for up to three minutes.
This means most conventional shrimp you buy, whether fresh, frozen, or at a restaurant, has been sulfite-treated. If you’re sensitive, look for shrimp specifically labeled “no sulfites added” or ask your fishmonger directly.
Processed Potato Products
Sulfites are added to peeled potatoes to stop them from turning brown, and they’re especially common in processed potato products. French fry cuts and hash brown-style potatoes tend to retain higher residual sulfite levels than whole peeled potatoes. Dehydrated potato flakes and any product containing them (instant mashed potatoes, boxed au gratin, certain soups) are frequent carriers as well.
Restaurant mashed potatoes and hash browns often contain detectable sulfite residues, since many kitchens use dehydrated potato products or pre-peeled potatoes treated with sulfiting agents. This is one of the harder sources to avoid when eating out, because it won’t appear on any menu.
Fermented and Aged Foods
Some foods contain sulfites not because they were added, but because fermentation produces them. This category includes aged cheeses, sauerkraut, vinegar, and even tea and coffee. The levels are generally lower than in foods treated with sulfiting agents, but they’re not zero. If you react to sulfites, these natural sources can still be relevant.
Other Common Sources
Several other processed foods regularly contain added sulfites:
- Condiments: pickles, relishes, horseradish, wine vinegar, and some mustards
- Prepared salads: coleslaw and pre-packaged salad mixes (to prevent browning of lettuce)
- Baked goods: some pie crusts, pizza doughs, and flour tortillas
- Canned and jarred foods: maraschino cherries, canned vegetables, and jarred sauces
- Molasses and corn syrup: used widely as ingredients in other processed foods
- Deli meats and sausages: some use sulfites as a preservative alongside or instead of nitrates
How to Spot Sulfites on Labels
In the United States, any food containing 10 ppm or more of sulfites must declare them on the label. The EU follows the same 10 mg/kg threshold. But the word “sulfites” isn’t always what you’ll see. Labels may list any of these names instead:
- Sulfur dioxide (E220)
- Sodium sulfite (E221)
- Sodium bisulfite (E222)
- Sodium metabisulfite (E223)
- Potassium metabisulfite (E224)
- Calcium sulfite (E226)
- Calcium bisulfite (E227)
- Potassium bisulfite (E228)
Two caramel colorings also contain sulfites: caustic sulfite caramel (E150b) and sulfite ammonia caramel (E150d). These show up in sodas, sauces, and other brown-colored processed foods, where they’re listed as colorings rather than preservatives.
One significant gap in labeling: foods below 10 ppm don’t have to disclose sulfites at all. And foods served in restaurants, at deli counters, or from buffets aren’t covered by these labeling rules. The FDA banned the use of sulfites on fresh fruits and vegetables sold raw (a response to severe reactions in the 1980s), but processed and cooked preparations remain fair game.
Who Needs to Watch for Sulfites
Sulfite sensitivity is concentrated heavily among people with asthma. An estimated 3 to 10% of asthmatic individuals react to sulfite-containing foods, with symptoms ranging from wheezing and chest tightness to more severe breathing difficulty. Among people without asthma, adverse reactions to sulfites are extremely rare.
If you suspect a sulfite sensitivity, the pattern to look for is respiratory symptoms that flare after eating high-sulfite foods, particularly dried fruits, wine, or restaurant potato dishes. Reactions typically come on quickly, often within minutes. Skin flushing, hives, and digestive symptoms can also occur but are less common than breathing-related responses.