🍷 Sulfite Calculator (SO₂)
Calculate sulfite additions to protect your wine from oxidation and microbial spoilage
Wine Parameters
Different wine types require different SO₂ levels
Typical range: 3.0-4.0 (lower pH = more effective SO₂)
If known from testing (0 if adding SO₂ for first time)
Will auto-populate based on wine type and pH
Results
Enter your wine parameters and click Calculate
About Sulfite (SO₂) in Wine Making
🛡️ Why Add Sulfites?
- Antioxidant: Prevents oxidation and browning
- Antimicrobial: Inhibits spoilage bacteria and wild yeast
- Preservative: Extends wine shelf life
- Flavor protection: Maintains fresh fruit character
📊 Target Free SO₂ Levels
- Red Wine: 25-35 ppm (lower tannins protect)
- White Wine: 35-50 ppm (needs more protection)
- Rosé Wine: 30-45 ppm
- Dessert Wine: 40-60 ppm (higher sugar)
⚗️ pH and Molecular SO₂
Lower pH makes SO₂ more effective. At pH 3.0, only ~6% is molecular SO₂ (active form). At pH 3.5, it's ~5%. At pH 4.0, only ~3%.
This is why wines with higher pH need more total SO₂ to achieve the same protection.
⏰ When to Add SO₂
- Crush: 30-50 ppm to prevent oxidation
- Post-fermentation: 20-30 ppm to stabilize
- Before bottling: Adjust to target levels
- Maintenance: Check every 3 months, adjust as needed
⚠️ Important Notes
- This calculator uses potassium metabisulfite (K₂S₂O₅), the most common form
- Campden tablets typically contain 550 ppm SO₂ each
- Free SO₂ naturally decreases over time - test regularly
- Always test actual SO₂ levels with proper equipment for accuracy
- Maximum legal limits: 350 ppm total SO₂ (varies by country)