Sulfites in wine. What they do, and can we live without them?

What sulfites do

Sulfites, in the form of sulfur dioxide (SO₂), are the winemaker’s most important protector. They prevent oxidation, which turns wine brown and flat, and they stop unwanted yeasts and bacteria from spoiling it.

They have been used for a very long time; burning sulfur in barrels to clean and protect them is an old cellar practice.

No wine is completely sulfite-free

Yeast naturally produces small amounts of sulfites during fermentation, so even wines without added sulfites contain some. That is why labels say “no added sulfites” rather than “sulfite-free”.

In both the United States and the European Union, wines with more than 10 mg/L must state “contains sulfites”. Legal limits are much higher, and dry red wines usually contain less than whites or sweet wines.

Do sulfites cause headaches?

Probably not, for most people. A small group of people, often with asthma, is sensitive to sulfites, but there is little evidence that sulfites cause the headaches some people get from wine. Many dried fruits contain far more sulfites than wine.

Can we replace them?

Natural winemakers use little or no added sulfur and rely on healthy grapes, hygiene and protection from oxygen. Scientists test alternatives such as protective yeast cultures, inert gas, careful filtration and other treatments.

In The Science of Wine, Dr. Jamie Goode puts the methods of winemakers and scientists to the test to see whether we can eliminate sulfites from winemaking.

Go furtherTo explore the estates, vineyards and wines of the Rheingau and Germany further, the wein.plus wine guide is a great resource.