Term
Sulfites
SUL-fites
The preservative everyone has heard of
Sulfur dioxide, used for centuries to keep wine from oxidizing and refermenting. All wine contains some; added SO₂ is the political part.
Yeast produce sulfites naturally. 'Contains sulfites' is on almost every bottle in the US. 'No added sulfur' wines can still test positive. People who get headaches from red wine are more often reacting to histamines, tannin, or alcohol than to sulfites — though a true sulfite allergy exists and is serious (usually in asthmatics).
Low-SO₂ winemaking is a stylistic choice that demands clean fruit and a cold chain. It is not automatically healthier or better.
If a wine smells of a just-struck match, that can be free SO₂, and it usually blows off.
