SO2 Additions Table

By Charles Plant

Sulphur Dioxide Additions Using Potassium Metabisulphite

This reference table provides guidance on dosing sulphur dioxide in winemaking. It indicates “the volume in mL of 10% Potassium metabisulphite solution to add a desired amount of Sulphur dioxide to a known volume of must or wine.”

The table is organized by container volume (ranging from 0.75 liters to 227 liters, or 0.17 to 50 imperial gallons) and desired SO2 concentration in parts per million (10–100 mg/L). Users can cross-reference their batch size and target SO2 level to determine the precise milliliter amount needed.

Solution Preparation

The potassium metabisulphite solution is prepared by “adding sufficient water to 100 g of Potassium metabisulphite to bring the total volume to 1000 mL.”

Important Considerations

“When you add Sulphur dioxide to a must or wine, it will not all remain as free.” Instead, some of the added SO2 immediately binds, with the proportion depending on prior additions.

Calculations are based on a 4.545 L/imperial gallon conversion and a 10% solution providing 5.7% available SO2 by mass.

Consult the companion article on the use of sulphur dioxide in winemaking for comprehensive guidance on application.