Barkoleen is used for treatment of new barrels to remove excess tannin. Use 1 lb. for 5 gallons of water and soak in the barrel for 3 days. Next, drain and flush 3 times with hot water and rinse with a solution of 2 oz. sodium sulphite, 1oz. citric acid, and 2 gallons of water. Finally, rinse the barrel with clean water.