The words “contains sulfites” appear on almost every bottle, yet few people know what they cover. Sulfites, or sulphur dioxide (SO2), are among the oldest additives in winemaking. They protect the wine, without which many would quickly spoil. Organic wine allows lower doses than conventional wine, which explains part of its appeal for many wine lovers. This article sets out the real role of sulfites, the limits allowed in organic and conventional wine, and the exact meaning of the phrase “no added sulfites”.
What are sulfites for?
Sulphur dioxide plays two complementary roles. As an antioxidant, it protects the colour and aromas of the wine by limiting its contact with oxygen. As an antimicrobial, it prevents the growth of unwanted bacteria and yeasts during winemaking and storage.
A small part of the sulfites is not added: fermentation naturally produces a few milligrams. The rest is added by the winemaker to stabilise the wine, in amounts that vary with the type of cuvée.
The allowed limits: organic versus conventional
European Regulation 2018/848 sets lower total SO2 ceilings for organic wines than for conventional wines. The thresholds depend on the colour and the sugar level of the wine.
| Type of wine | Organic (max total SO2) | Conventional |
|---|---|---|
| Dry red | 100 mg/L | 150 mg/L |
| Dry white and rosé | 150 mg/L | 200 mg/L |
| Sweet wine | 370 mg/L | 400 mg/L |
“Contains sulfites”: what the label says
The words “contains sulfites” are mandatory as soon as the wine exceeds 10 mg/L of SO2, under the labelling of allergenic substances. They therefore concern almost every wine, organic included.
The phrase “no added sulfites” means that no SO2 has been added by the winemaker. The wine may still contain the natural sulfites produced by fermentation. A wine with no sulfites at all is therefore nearly impossible.
Should we fear sulfites?
Sulfites are listed among the substances that must be declared because a minority of people are sensitive to them. Reducing the doses, as organic winemaking does, answers this concern without sacrificing the keeping of the wine.
For most wine lovers, the issue is mainly one of dose and balance. A well-made wine uses SO2 with restraint, just enough to protect the wine.
Frequently asked questions
Does organic wine contain sulfites?
Yes, but capped at a lower level than in conventional wine. An organic red is limited to 100 mg/L of total SO2, against 150 mg/L for a conventional red.
Can a wine be completely free of sulfites?
No, or almost never. Fermentation naturally produces small amounts of sulfites. “No added sulfites” only means that no SO2 has been added.
Why are sulfites added to wine?
To protect it: SO2 is both an antioxidant, which preserves colour and aromas, and an antimicrobial, which prevents the growth of unwanted micro-organisms.
Going further
Sulfites illustrate the care taken in winemaking, a field where organic wine sets its own requirements. Our article organic wines: between commitment and constraints details the specifications, and biodynamics extends this reflection on living soils.
Château d’Arsac, in the Margaux appellation, makes its wines with the same attention to balance.
