Oak barrels are traditionally used to age whiskey and can be used to age wine as well. Oak wood is strong enough to be shaped into a barrel, and oak is pure—it has no resins that can pass unwanted flavors to the spirits. The chemical reaction between the wood and the alcohol produces the pleasant and desired taste. Oak barrels must be cared for in a specific way, however, to make a good-tasting spirit.
Curing the Barrel
Rinse the inside of the barrel to remove any debris. Fill the barrel completely with water until it overflows from the bunghole.
Place the bung in firmly, so the barrel is airtight.
Let the barrel sit filled with water for three to five days, or until the barrel swells. Check for leaks every few hours. If the barrel leaks, keep it filled in order to cure it completely. (The barrel swells when saturated with water. This expansion closes in the leaks between the staves.)
Add your spirits and begin aging them when your barrel stops leaking.
Caring for Your Barrel
Keep your barrel from drying out. Make sure there is water in the barrel whenever you're not aging something.
Keep the oak barrel away from harsh conditions. Humidity, dryness, direct sunlight, rain, air conditioner or heater vents—all these things can hurt your barrel. For best results, always keep your barrel indoors at a moderate temperature. Homes that are heated too high cause more evaporation than normal.
Resist the urge to varnish your barrel. If a barrel is varnished the natural tannins that are released from the wood will be hindered. The oak flavors will be lost, and the spirits will be contaminated by the varnish.
Cleaning Your Barrel
Mix four ounces of Barolkleen with 1.25 gallons of hot water.
Soak the the barrel with the solution for three days. Roll the barrel regularly to get the solution on every interior surface. Drain and flush three times with hot water. Allow the barrel to drain for at least one hour.
Remove the spigot. Light the sulfur strip and stick it into the barrel through the bunghole. Do not drop the lit sulfur strip into the barrel. The sulfur strip sanitizes the barrel by releasing a sulfur gas. This prevents microbial growth inside the barrel.
Mix two gallons of water with one ounce of citric acid. Pour it into the barrel and swish it around for five minutes.
Empty the barrel and rinse three times with hot water. The barrel should drain for three hours before being filled.