Campden Tablets, 0.55 gram each. 100 Tablets. 48% SO2. One tablet per gallon yields about 75 ppm.
We recommend 1/2 tablet per gallon at each racking. The tablets need to be crushed before adding. For this reason most people prefer the powdered form (Potassium Metabisulfite). Campden tablets may be either sodium metabisulfite or potassium metabisulfite .