Barrel Kleen must be neutralized with citric acid prior to contact with your wine 

Use at the rate of 1/2 to 1 pound per 5 gallons hot water solution at the rate of 4-10 pounds of barrelkleen per 50 gallon barrel. Range re barrel condition. Top up barrel with hot water-barrelkleen solution. Soak 24-48 hours. Rinse WELL, until water runs clear. ALWAYS Neutralize after Barrelkleen or Soda Ash washes by mixing 1-2 oz. Citric acid and 2 oz Potassium Metabisulfite per gallon of water . Use 1 gallon of this solution for a 5 gallon barrel, 2 for a 10 gallon barrel, etc. Roll well in barrel, contacting heads and all surfaces. Repeat if desired. (If you fail to neutralize, your wine will do that job.) Drain and rinse.