Why Sulfites Are Used
Sulfur dioxide serves two critical functions in winemaking:
- Antioxidant — protects wine from browning and loss of fresh fruit character
- Antimicrobial — prevents spoilage bacteria and wild yeast from causing off-flavours
Natural vs. Added Sulfites
All wines contain some naturally produced sulfites (5-20 mg/L from fermentation). Conventional wines typically contain 50-150 mg/L total SO₂. EU law caps sulfites at 150 mg/L for reds and 200 mg/L for whites/rosés.
Sulfites and Health
About 1% of the population has sulfite sensitivity, which can trigger asthma-like symptoms. For most people, sulfites in wine are harmless. The "wine headache" myth is more likely related to histamines, tannins, or dehydration than sulfites.
Low-Sulfite and Natural Wines
Natural winemakers aim to minimise or eliminate added sulfites, relying on meticulous hygiene and healthy grapes. These wines can be vibrant and expressive but are more fragile and best consumed young.