Approximately 100 tablets made with Potassium Metabisulfite
1 tablet per gallon equals 30 ppm free SO2
Campden tablets (potassium metabisulfite) are a sulfur based product that is used primarily in wine, cider and beer making to kill certain bacteria and to inhibit the growth of most wild yeast: this product is also used to eliminate both free chlorine, and the more stable form, chloramine, from water solutions (i.e., drinking water from municipal sources).
Campden tablets allow the amateur brewer to easily measure small quantities of Potassium metabisulfite, so it can be used to protect against wild yeast and bacteria without affecting flavor.
Measured by weight, tablet count is approximate due to variations in the actual tablets