degassing

[montepaulsen]

Profession winemakers sometimes need to de-gas wines prior to bottling. Generally the problem arises when bottling a young wine right after harvest, such as a white zin that you want to release by Thanksgiving.

Yound white wines and blushes are often fermented cool, and if we wish to finish the wine with residual sugar, we'll chill the tank at the very end, which slows fermentation drastically, but also serves to retain CO2. You can often tell if your wine has too much CO2 in it by pouring a glass out of a cold tank (or cool carboy) and setting it somewhere to rise up to room temperature. If it has too much CO2, it'll begin developing bubbles on the inside, not to mention having a slight spritzy taste. It can also be a problem with aged wines that are in a container with headspace, if you use CO2 to sparge the headspace. The problem is compounded by cooler storage temperatures.

The professional method for degassing is to lower a sparge stone (like an aquarium air stone, only stainless) and bubble nitrogen into the wine, which pulls out CO2 as it rises. You could simulate this on a small scale, using Nitrogen based wine bottle preservers, in those aerosol cans with the supplied plastic sparge tube. But be careful - that stuff shoots out pretty quick, and if you do indeed have a lot of CO2 in the wine, you'll have a frothy mess on your hands.