It is time-tested and experience-proven that wooden barrels are the best way to store wine for optimum flavor, body and freshness. Like any storage material, these barrels get dirty over time and should be cleaned between each batch of wine that the barrel holds. Storing wine produces the buildup of tartrate coatings and yeast molecules, which can ruin the wine's aging process and destroy the taste that wooden barrels are meant to maintain. A proper, thorough cleaning will keep your wine tasting fresh, whether the barrel is holding its first or hundredth batch of wine.
General Cleaning
Rinse the barrel with hot water under pressure. This can be done with either a garden hose with a spraying head or a pressure washer.
Rinse again with cold water under pressure.
Rinse in this manner each time the barrel is emptied. Full-scale cleanings will only be needed if you notice a buildup on the walls of your barrel or a change in taste in your wine.
Full-Scale Cleaning
Rinse the barrel as previously instructed for general cleaning. Fill the barrel halfway with cool water.
Dissolve sodium percarbonate cleaner in warm water in a separate bucket. This type of cleaner can be found in home improvement stores or from Internet retailers. Use 1/8 cup of cleaner for a 23-25 liter barrel; 1/4 cup for a 46-50 liter barrel; 1/3 cup to 1/2 cup for a 100 liter barrel; or 2/3 cup to 3/4 cup for a 225 liter barrel.
Mix the cleaning water into the barrel, and fill the barrel the rest of the way with cool water. Bung, or cover, the barrel and let the solution soak in the barrel for 24 hours.
Empty the barrel and rinse, beginning with hot water and following with cold. Repeat the rinsing process until there is no residual cleaner left.
Neutralize the barrel with a citric acid cleaner, which is also available at home improvement stores or Internet retailers. Mix 1/3 cup of citric acid cleaner in a full 23-25 liter barrel; 2/3 cup of cleaner in a full 46-50 liter barrel, 1 1/2 cups in a full 100 liter barrel; or 3 cups in a full 225 liter barrel. Let it sit for 24 hours, and then rinse thoroughly as before.