Definition - What does Degas mean?
Degassing is a process in which gases are removed from a wine (or any liquid), especially before bottling. The formation of carbon-dioxide is a natural occurrence during the fermentation process, but it is an unwanted quality in still wines.
Three ways to remove gas from wine:
- Using a vacuum
- By agitation
WineFrog explains Degas
One of the by-products of fermentation is carbon-dioxide. A large quantity of the gas is released throughout fermentation by pump-overs and proper ventilation of the fermenting wine in its container. However, some carbon-dioxide will stay in the wine. This is not a desirable quality in still wines.
The three methods of degassing a wine mentioned above are further explained here:
Using a Vacuum to Degas Wine
There are special vacuums made for this purpose. The carbon dioxide is removed by a negative pressure in the wine vat.
Using Agitation to Degas Wine
Agitation is the simplest way to degas a wine. A special stirring rod is attached to a drill and the wine is agitated (stirred) to release the carbon dioxide.
Aging Wine to Degas it
Aging is the most time-consuming way to degas a wine, but the results are better and it is the most common way wineries will degas their wines. Aging a wine naturally in oak or stainless steel allows for the wine to rest and naturally release gases over time. It allows the wine to settle, which also permits unwanted solids to precipitate from the wine. These solids are separated via racking, which also allows gases to escape during the process.