What are sulfites and are they dangerous?
Quick answer
Sulfites are sulfur-based preservatives found naturally in all wine and often added during winemaking. At the levels permitted in the EU (up to 150 mg/L for reds, 200 mg/L for whites), they are safe for most people.
Detailed answer
Sulfites — specifically sulfur dioxide (SO₂) — have been used in winemaking since Roman times. They serve two critical roles: as an antioxidant protecting wine from spoilage and browning, and as an antimicrobial agent preventing unwanted bacteria and yeast from taking over. Every wine contains some sulfites naturally, as fermentation itself produces between 10 and 30 mg/L.
EU regulations cap sulfite levels at 150 mg/L for dry reds, 200 mg/L for dry whites and rosés, and 250 mg/L for sweet wines. Organic wines must stay below 100 mg/L (reds) or 150 mg/L (whites). Natural wines often target under 30 mg/L total. The label warning "contains sulfites" is required whenever the level exceeds 10 mg/L, which applies to virtually all wines.
Are sulfites dangerous? For roughly 99% of people, no. About 1% of the population — predominantly severe asthmatics — can experience reactions including headaches, flushing and breathing difficulty. If you regularly eat dried fruit (which can contain up to 2,000 mg/kg of sulfites — roughly ten times the concentration in wine), processed shrimp or packaged fruit juice without issues, wine sulfites are unlikely to bother you.
If you prefer lower-sulfite options, look for organic or natural wines on expertvin.be. These styles use minimal additions while relying on careful cellar hygiene to keep the wine stable.