Sparging is a process used to remove excess dissolved oxygen, as well as CO2, from a wine. In sparging a wine, inert gas is introduced into the wine, as fine bubbles developing pressure between the inert gas and the dissolved oxygen, forcing the oxygen out of the wine. The most common inert gases used in sparging wine are nitrogen (N2) or CO2.
The process of sparging is not universally accepted as many winemakers feel it strips too many flavor compounds out of the wine.