Maintenance of drums "wet".
It is basically the same method, as described above, but has one decisive advantage; it requires a lot of water, but the barrel remains moist, and the next wine will not seep into the wood.
On 100 liters (1 hectolitre) the capacity of the barrel dissolves 100 g of potassium metabisulfite in one liter of water and added to this 20 g of tartaric acid. Then the barrel must be filled with water, mix thoroughly and seal it with a well-fitting plug. Potassium metabisulphite dissolved in water and activated with acid (K2S2O5), gives off more than half of its mass in the form of sulfur (SO2) which means, that one tablet 10 g works the same as 5 g of sulfur. For comparison: 10-a gram portion of sulfur gives 20 g of sulfur oxide, and therefore double the amount. A barrel filled with this mixture is preserved for about a year. However, it should be done from time to time, especially in dry cellars, check the water level. In the event of a loss, you need to add clean water to the tap.