How to Use Sodium Metabisulfite in Winemaking

What is Sodium Metabisulfite?

Sodium metabisulfite is a common winemaking additive used to sanitize equipment and to protect wine from oxidation and spoilage by inhibiting wild yeast and bacteria. It releases sulfur dioxide (SO₂), which acts as a preservative and antioxidant.

Uses in Winemaking

• Sanitizing Equipment: It is used to sanitize fermenters, bottles, corks, and other winemaking tools to prevent contamination.
• Protecting Must and Wine: It helps control wild yeast and bacteria, especially before fermentation begins and during bottling.
• Preventing Oxidation: Added after fermentation or before bottling to preserve the wine's freshness and prevent browning.

How to Use Sodium Metabisulfite

1. Sanitizing Equipment

• Dissolve 1 tablespoon (about 15 g) of sodium metabisulfite in 1 gallon (3.8 L) of water.
• Soak all winemaking equipment in the solution for several minutes.
• Drain and let air dry. No rinsing is required for most applications.

2. Adding to Must or Wine

• For fresh must (crushed grapes or juice): Add 1/4 teaspoon per 5 gallons (19 L) to suppress wild organisms. Wait 24 hours before adding yeast.
• For finished wine (prior to bottling): Use 1/4 teaspoon per 5 gallons to help prevent spoilage and oxidation.

3. Measuring and Adding

• Always dissolve sodium metabisulfite in a small amount of water before adding it to the wine or must. Stir well to ensure even distribution.
• Measure carefully, as too much can impart off-flavors or be harmful. Too little may not protect your wine effectively.

Safety Precautions

• Handle with care in a well-ventilated area to avoid inhaling fumes.
• Store in a cool, dry place, away from children and pets.
• Label all solutions clearly.

Summary

Sodium metabisulfite is an essential tool for both sanitizing and preserving wine during the winemaking process. Correct dosage and handling will ensure your wine stays fresh and free from unwanted spoilage.