5.3.3.b What are the preparatory steps prior to the initial filling?

Is it necessary to clean new barrels with pressurized hot water?

The first objective when using pressurized hot water to clean barrels is to verify their watertightness. It also enables very bitter tannins to be removed, which are easily extractable in the liquid phase. This process is performed after the barrel's quality inspection.
Example of hot water pressure cleaning protocol for new barrels.

1. The barrels are filled with about 25 litres of hot water and then sealed (wooden bung + linen).
2. The water is moved around both ends of the barrel and on the side of the bunghole, and left standing on one end for 24 hours.
3. The barrels are then inverted and left to stand on the other end for another 24 hours.
4. Finally, the barrels are rinsed using a cold water/hot water/cold water cycle.
5. After this rinsing, the barrels are drained for a period of 48 to 72 hours before being filled.

Is it necessary to burn sulphur discs in new barrels?

There is no need to burn sulphur discs in new, well-stored barrels if they are clean and dry. There is no risk of microbiological contamination. Burning sulphur discs is therefore unnecessary.

What type of bung should be used at this stage?

The type of bung to be used depends on the wine's condition. If the wine has not yet undergone malolactic fermentation when it is transferred to barrels, a glass bung is the most appropriate. This will allow CO2 to be released without risk. After MLF, there is a choice of a silicon or wooden bung. The difference between them is the amount of oxygen they allow to enter (see the chapter regarding oxygen during barrel ageing).