Ageing wine in a vessel before bottling allows the wine’s aromatic profile to become more developed and increase the complexity of the wine's structure.
During the ageing process there are additional actions that can be taken such as Ouillage, Racking off, and Stirring. Ouillage is the act of topping up the vessels with wine as the liquid evaporates over time. Known as the “angels’ share”, the evaporated wine can alter the colour and aromas through oxidation which is best avoided through topping up regularly. Often done to move the wine off the lees, Racking Off is the process of oxygenating the wine by moving it between vessels. The amount of times this is done is at the discretion of the winemaker.
Stirring is a regular action that needs to be done two to four times a month to ensure the lees remain in contact with the wine. While optional, it does help improve the fatness of a wine as well as limiting the oxidation on the surface of the wine. Performed with a traditional spatula-shaped tool called a dodine in Burgundy, other winemakers around the world use similar implements to replicate the process. Stirring is primarily performed by white wine makers as they generally have more lees during ageing.
Barrels vs Vats
Wines aged in barrels develop a lot more of an aromatic profile, this is due to the porous nature of oak barrels allowing an exchange between air and wine. As expected it also brings an oaky tone to the wine’s aromas.
Vat ageing of wine ensures no oak tones are carried across and savours the youth and freshness of a wine while developing the deeper flavours. Generally speaking they are used for wines that are to be drunk in their youth.