Zero Sulfite / No Added SO₂

What It Means

Sulfur dioxide (SO₂) has been used in winemaking since Roman times as an antimicrobial and antioxidant. "Zero sulfite" or "no added SO₂" means the winemaker adds no sulfur at any point — not at harvest, not during fermentation, not at bottling. Some residual SO₂ is produced naturally during fermentation (typically 5–15 mg/L), which is why absolute zero is rarely achievable.

The Challenge

Without SO₂, wine is vulnerable to oxidation, Brettanomyces, and other microbial spoilage. Zero-sulfite production requires near-perfect fruit (any rot introduces spoilage organisms), exceptional cellar hygiene, and careful temperature management throughout shipping and storage.

The Argument for It

Proponents argue that SO₂, even at legal minimums, suppresses the full aromatic potential of wine — that a wine without it tastes more alive, more expressive of its fruit and terroir. The compromise, of course, is fragility.

In Champagne

The pressurized environment of champagne (5–6 atmospheres of CO₂) provides natural protection against oxidation — one reason zero-sulfite production is more achievable in sparkling wine than in still. Romain Henin produces all his wines with zero added sulfur. The results are some of the most vivid and expressive champagnes we have tasted.