Degassing Wine

updated 10/10/2024

Is degassing necessary, and if so, how does one do it?

To Degas, or not Degas, that is the Question!

This is a highly important question — is it necessary to degas a wine?

The short answer: most of the time, no. It’s not necessary.

Given sufficient time, which can be three months or more, most wines degas naturally. For people who are bulk aging at least 3 months, exercising patience gives the wine time to degas. I have noted that heavier bodied wines may take longer to degas naturally.

However, some wines refuse the degas, and this holds sediment in suspension, so the wine does not clear. While in my experience this is rare, it does happen.

Note that wine not clearing is more likely due to pectin haze or protein haze, which are solved with pectic enzyme and bentonite, respectively.

Why Degas Wine?

Degassing wine is not a bad thing. In my experience, the most common reasons for degassing are:

Wine not clearing. As noted above, some wines fail to degas, or are degassing very slowly. In this rare instance, manual degassing is necessary.

Impatience. The winemaker wants to bottle that wine! Bottling wine that is not fully degassed is likely to produce mini-volcanoes, so degassing is the answer.

Kit instructions. Kits focus on bottling quickly, as if the instructions state that the wine won’t be drinkable for 12 months, most people would not buy the kit. This is similar to “Impatience”, but it’s typically people following kit instructions rather than simply being impatient.

It is recommended. Folks read things in a blog, or see in a video, or hear from a friend. So that’s what they do.

How to Degas Wine?

Kit instructions typically say to stir or whip wine for upwards to 10 minutes. I saw one video from a popular homebrew store that said to stir the wine for one full hour.

One full hour? That is extremely bad advice, lending itself to idiocy.

Why?

Degassing is the removal of excess CO2. Wine always contains some CO2, an amount below a threshold where it won’t come out of suspension on its own. This is acidic, and helps with the flavor profile of the wine. Removing all CO2, if actually possible, may make the wine flat and insipid tasting.

Additionally, stirring for an hour will introduce O2 into the wine, which leads to oxidation.

Based upon research and practical experimentation, I developed the following simple method:

Once fermentation has completed, rack the wine off sediment or press the pomace to produce clear wine, using a larger open container (such as a primary fermenter) as the receptacle.

Stir the wine for 30 seconds. I use a drill-mounted stirring rod, and produce a small vortex with a hollow space in the center of the primary. This typically foams a lot, releasing a lot of CO2. I am not “whipping” the wine.

Reverse the drill, and once the small vortex is created in the reverse direction, stir for 30 seconds.

Rack the wine into secondary storage and place it under airlock.

That’s it.

What this does is jump start the degassing process, releasing a lot of CO2 from the wine. From there I rack it into secondary storage, where the remainder of the degassing process completes over the succeeding weeks. In rare cases it may take a few months, but I bulk age all wines at least 3 months, so it doesn’t matter if the wine takes a few months to complete degassing.

Some folks claim stirring produces oxidation, but the amount of CO2 released during the brief stirring pushes all air away from the wine. Again based upon my experiences, this is not a problem. Besides, I add K-meta at each racking, which addresses any O2 that is introduced.

Conclusion

Should all wines be degassed?

That’s up to each winemaker. I do it as it takes little effort, and since my heavy reds spend a year in the barrel, it’s useful to have less fine lees in the barrel. [I normally let reds clear for 2 to 4 weeks before moving to barrel.]

Note that some folks degas using a vacuum pump, which apparently works well.