Barrel Cleaning & Storage Tablets are pre-measured doses of sulfates formulated to kill bacteria and inhibit the growth of yeast and microbes in the barrel. When storing or cleaning your barrel between uses, dissolve the appropriate number of tablets in water. Pour mixture in the barrel and fill completely with additional water. Store in cool damp conditions if possible. Rinse 3x prior to use. Sanitize your barrel with a Barrel Tablet after 2 or 3 uses.