Use our SO2 Wine Calculator to accurately determine sulfur dioxide additions for your winemaking. Achieve optimal free SO2 and molecular SO2 levels based on your wine's pH, crucial for stability and preventing microbial spoilage. Essential for crafting quality wines.
Formula:
The calculator determines the necessary Potassium Metabisulfite (K-Meta) addition to reach a target Free SO2 level, which is itself derived from your wine's pH and a desired Molecular SO2 concentration.
Target Free SO2 (ppm) = Desired Molecular SO2 (ppm) × (1 + 10(pH - 1.8))
Grams K-Meta = (Target Free SO2 - Current Free SO2) × Volume (L) ÷ 576
Where:
- Desired Molecular SO2: The protective form of SO2, typically targeted at 0.8 ppm for red wine or 0.5 ppm for white wine.
- pH: The acidity level of your wine.
- 1.8: An approximate pKa value for SO2 in wine at wine conditions.
- Current Free SO2: The existing amount of unbound SO2 in your wine, typically measured in ppm (mg/L).
- Volume (L): The total volume of your wine in liters.
- 576: A conversion factor reflecting that Potassium Metabisulfite (K-Meta) is approximately 57.6% SO2 by weight, used to convert mg/L to grams.