The main thing you should understand before using an oak barrel is that a barrel is made of natural material (oak wood). Oak reacts to water, air, temperature and time. If the wood becomes too dry due to sunlight, warm air, temperature changes or constant airflow, the barrel can start leaking and may even crack. This is a natural behavior of oak and not a defect.
At the same time, an empty barrel should not be stored for a long time in a damp environment or in conditions of high external humidity. In such conditions, the wood can swell unevenly and mold may develop on the outer surface of the barrel. For this reason, both proper preparation and correct storage are important.
The best practice is to buy a new oak barrel when you are ready to use it and avoid long-term empty storage.
Once you receive your barrel, inspect it before preparation. Check the staves and heads for cracks or gaps, make sure the hoops are tight and properly seated. Inspect all parts including the tap (spigot), bung and stand. To inspect the inside of the barrel, insert a light into one bung hole and look through the opposite hole.
A new oak barrel must always be prepared before first use. Preparation allows the wood to absorb water, swell naturally and seal itself.
Water Quality – Important Note
For preparing an oak barrel, it is recommended to use clean, chlorine-free water. Chlorine present in tap water can react with natural oak components and may affect the aroma and taste of the liquid later stored in the barrel. If tap water is used, letting it stand overnight allows most of the chlorine to dissipate. Filtered or bottled water can also be used.
How to Prepare an Oak Barrel for Use
Before filling a barrel with wine, spirits intended for aging, beer or other beverages, the barrel must be swelled with water so it can seal itself naturally.
There are two well-known methods used for this purpose:
– soaking with cold water
– soaking with hot water
Do not submerge the barrel completely in water.
Soaking Barrel with Cold Water
Rinse the barrel inside 3–4 times with clean, cool water to remove any wood dust and debris. A funnel may be used for convenience. Fill the barrel slightly more than half full, shake it well, and drain the water. Repeat this process several times.
Insert the spigot into the tap hole by hand. Lightly tap it with a hammer to fix it in place (2–3 light taps). Do not hammer with full force. If the barrel has glass heads, the spigot must be inserted by hand only.
Place the barrel on its stand.
Fill the barrel gradually — first to about one third of its volume and leave it for 3–4 hours, then increase the level to two thirds and leave it for another 3–4 hours, and finally fill the barrel completely to the top.
At the beginning, the barrel may leak. This is normal. Place it in a sink, tray or another area where small leaks can drain safely.
Leave the barrel full of water until all leakage stops. If the barrel is leaking, check it regularly and add water as needed to keep it completely full. Even if the barrel appears to be sealed after a few hours, it is still recommended to keep it filled with water for at least 48 hours to allow the wood to swell evenly. Normally, the sealing process takes from 1 to 6 days, depending on how dry the barrel was before soaking. During soaking, the barrel should be kept in a well-ventilated area. If soaking lasts longer than 2 days, the water should be changed to clean water regularly to reduce the risk of mold or bacterial growth.
When leakage has stopped, drain the water through the bung hole, rinse the barrel once again, and place it on the stand with the bung hole facing down. Let the barrel stand empty for about 1 hour. After that, the barrel is ready for use. It is not recommended to leave the barrel empty for a long time, and it is best to fill it as soon as possible after preparation.
Do not drain water through the tap, as small wood particles may clog it.
Soaking Barrel with Hot Water
Rinse the barrel inside 3–4 times with clean, cool water to remove any remaining wood dust. Insert the spigot by hand, then secure it with a few very light taps of a hammer (2–3 light taps). Do not hit hard.
Place the barrel on its stand. Pour hot water at approximately 70–80 °C through the bung hole, using about 25% of the barrel volume. For example, a 10-liter barrel requires about 2.5 liters of hot water. This method should not be used for barrels with glass heads.
Insert the bung and tighten it by hand. Slowly rotate the barrel on its stand for about 10–15 minutes, changing its position every few minutes so the hot water can reach all internal surfaces.
Remove the bung, turn the barrel so the bung hole faces down, drain all water completely, and allow the barrel to cool naturally. Be extremely careful when removing the bung, as hot steam may escape under pressure. Hot steam can create pressure inside the barrel and may push the bung or spigot out. Keep your hands away from the openings and do not lean over the barrel.
After the barrel has cooled, fill it completely with clean, cool water and leave it standing. Even if no seepage is visible, it is recommended to keep the barrel filled for about 48 hours so the wood can swell evenly. If the barrel leaks, check it periodically and add water as needed to keep it full. Depending on how dry the barrel was, sealing may take from 1 to 6 days. During soaking, keep the barrel in a well-ventilated place. If water remains inside for more than 2 days, drain it and replace it with clean water.
Once the barrel is fully sealed and dry on the outside, drain the water through the bung hole, rinse the barrel once again, and place it on the stand with the bung hole facing down. Let it stand empty for about 1 hour. After that, the barrel is ready for use. It is not recommended to leave the barrel empty for a long time, and it is best to fill it as soon as possible after preparation.
Avoid draining through the spigot, as small wood particles can clog it and affect its proper operation.
Storage of the Barrel During Aging
– Store in a cool place (13–15 °C)
A stable, cool temperature helps the barrel age evenly and reduces stress on the wood. Avoid warm rooms and sudden temperature changes.
– Maintain humidity around 65–75%
This humidity level prevents the barrel from drying out too quickly while avoiding excessive external moisture on the wood surface.
– Avoid direct air streams or drafts
The barrel should not be exposed to constant airflow or drafts, as directed air can dry the wood unevenly, especially around joints and heads.
– Ensure proper room ventilation
The storage area should be ventilated to allow slow air exchange and prevent stagnant, damp conditions. Ventilation should be general, without air blowing directly onto the barrel.
– Keep away from direct sunlight
Direct sunlight heats the barrel and accelerates drying of the wood, which may lead to leaks or cracks over time.