At the very center of wine making is the process of fermentation. Fermentation occurs because the yeast want to consume the sugars in a wine must. As a result, the sugars are converted into both alcohol and CO2 gas by the fermentation. Normally as winemakers, we are concerned about the alcohol, but in this post we are going to change directions and talk a little about the gas.
Almost all of the CO2 produced during a fermentation dissipates into the air and goes away very quickly, but not all of it. Any liquid – wine included – has the ability to hold some CO2 gas for a period of time. It stays saturated in the wine. This CO2 gas is the same stuff that puts the fizzy in soda pop, beer and even the sparkle in sparkling wines, but when it comes to still wines we don’t want CO2 gas to do anything but be gone.
A Little Degassing Background
When I first started making wine, degassing was not even a word in the winemaker’s vocabulary. Finished homemade wines always sat around long enough in bulk glass jugs clearing and aging and whatnot, that they degassed themselves naturally with time. Wines back then needed extra time, and along with this time the wine was able to release all the CO2 gas it contained.
But things changed when 28 day and 6 week wine kits came onto the scene. These kits allowed the home winemaker to bottle their wines in a relatively short amount of time. This is not enough time for the CO2 gas to escape on its own. Because of this, the wine kit producers added the extra step of degassing in their directions they included in the kit.
How Do You Degas A Wine?
A portion of the CO2 gas can stay saturated in a wine indefinitely because the gas molecules will lightly bond with the wine, but by agitating the wine with something as simple as a stirring spoon, the gas molecules will start to release and float to the surface and dissipate. If you stir the wine long enough, all but an untraceable amount of the CO2 gas will be released. The amount of time it takes to degas a homemade wine the with a stirring spoon can vary greatly. It could take a few minutes or a few hours depending on how much CO2 is still in the wine at this point.
One way to speed up the process is to use a degassing/mixing paddle. The paddle attaches to a hand drill just like a drill bit would. This significantly reduces the amount of labor and time needed to degas a wine.
Another way of degassing a homemade wine it by putting the wine under a vacuum. This can be done with a wine preserving vacuum pump, like our Vacuvin Wine Saver or any other hand-held wine preservation system to degas the wine. By putting the vacuum pump directly over the air-lock hole of a rubber stopper, you can literally suck the CO2 gas out of a glass jug.
Ed Kraus is a 3rd generation home brewer/winemaker and has been an owner of E. C. Kraus since 1999. He has been helping individuals make better wine and beer for over 25 years.