Potassium Metabisulfite is used to preserve and stabilize a multitude of fermented beverages. It forms sulfur dioxide (SO2) when added to wine preventing oxidation. It also stops wild organisms from developing. It can also be used as a sanitizer (no rinse).
*Usage: Dosage varies, but 1/4 teaspoon of potassium metabisulfite per 5 gallon batch = 50 ppm of free SO2. To use as a sanitizer; Mix 8 teaspoons into 1 gallon of water then apply, clean, and rinse with cold water.