Approximately 110 tablets made with Potassium Metabisulfite. 1 tablet per gallon equals 30 ppm free SO2. Each tablet is about 0.5 g.
Campden Tablets are used to preserve and stabilize wines, ciders, and occasionally beers. When added to wine or must, it forms sulfur dioxide gas (SO2). This prevents most wild microorganisms from growing and acts as a potent antioxidant, protecting both the color and delicate flavors of wine. Potassium Metabisulfite solutions are also used as sanitizing rinses for winemaking equipment.