What is Degassing?
Okay, so this question automatically brings up at least a half dozen jokes, all typically centered around the theme of not eating that grande bean burrito for last night's dinner. But seriously, degassing is an important tool in our winemaker's bag of tricks to make a higher quality wine.- Degassing: Degassing is the process of removing dissolved carbon dioxide (CO2) from the wine after fermentation. During fermentation, yeast produces CO2 as a byproduct, which can remain dissolved in the wine. In fact, at the end of fermentation, all wines will be slightly carbonated.
Why is Degassing Important?
- Preventing Fizz: Residual CO2 can cause a fizzy or carbonated effect in still wines, which is not what you want unless you're making sparkling wine. Some people find this fizziness extremely annoying.
- Helping to Clear the Wine: Degassing the wine will help in the clearing process of the wine.
How Improper Degassing Affects Wine's Clarity
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CO2 and Fining Agents: During maturation and clarification, if CO2 is still present in the wine, it can cause fine bubbles that keep these particles suspended, reducing the effectiveness of fining agents and preventing them from settling properly. Fining agents like bentonite or gelatin work by binding to particles (proteins, tannins, yeast, etc.) and causing them to settle out of the wine. Dissolved CO2 can interfere with this process.
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Particle Suspension:
- Suspended Particles: Dissolved CO2 creates micro-bubbles that can attach to particles in the wine, keeping them in suspension rather than allowing them to settle to the bottom.
- Hazy Wine: These suspended particles contribute to haze, preventing the wine from clearing sufficiently.
Proper Degassing Techniques
To ensure your wine clears properly, it’s important to degas it thoroughly. There are numberous methods for degassing:
- Manual Stirring: Vigorously stir the wine with a long-handled sanitized spoon or drill-mounted degassing wand to release CO2. This is the most common technique by home wine makers.
- Vacuum Pump: Use a vacuum pump to create a negative pressure, which reduces the CO2's solubility and pulls the CO2 out of the wine. Vacuum pumps work great in heavy duty stainless steel tanks, but a strong vacuum could implode a bucket or break a carboy.
- Time and Temperature: Allowing the wine to sit for an extended period and keeping it at a slightly warmer temperature can also help CO2 naturally escape. This works by natural diffusion. Gas always moves from a higher concentration to a lower concentration. With enough time, the dissolved CO2 in the wine will diffuse through the water in the airlock until it reaches an equilibrium with the natural CO2 concentration in the atmosphere, which is low.
Summary
In case you weren't listening, or if you have short term memory loss or perhaps you thought this was an article about Taylor Swift, the key points are worth repeating. Proper degassing is important for these reasons:
- Enhanced Clarification: CO2 removal helps fining agents work effectively by allowing particles to settle.
- Preventing Haze: Reduces the likelihood of suspended particles causing haze.
So grab your long-handled stirring spoon and get mixing, because a properly degassed wine leads to a clearer wine, and the faster we can clear our wine, the sooner we can bottle and drink it, which makes everybody happy.