Definition: Ouillage

The process of regularly topping up wine from the same source and of the same quality to compensate for loss through evaporation or after decanting, racking, etc. in vats, casks and barrels, in order to keep them full and prevent oxidation. The term 'ouillage' comes from the word 'œil', which is also used to refer to the bunghole. The level of the wine should always be flush with the bunghole.