Sodium Metabisulfite (SMS) prevents wild yeast, bacteria growth, and oxidation in your wine. Sodium Metabisulfite also works well as a sanitizer for your wine-making equipment. As a sanitizer – use 2 oz per 1 gallon of water. As an antioxidant & bactericide – use 1/4 teaspoon to 6 gallons. Dissolve sulphite in warm water before adding.