Degassing? When? Why?

[Blue-Frog]

The concept seems strange to me... I usually just age it in bulk before bottling and haven't noticed any carbonation in the bottled wine. Is there something I am overlooking, or is all the drilling/degassing I see people doing just so they can get the wine in the bottle quicker?

 

[Stigmond13]

You've answered your own question. If you leave for 6 months there is very little chance of carbonation after bottling (unless you are backsweeting without killing of the yeast of course).

 

[bernardsmith]

But many folk degas during active fermentation. This to reduce the pressure on the yeast and perhaps to reduce the acidity (carbon dioxide can form carbonic acid and if the must is close to the yeast's tolerance for acidity then removing the CO2 can be effective.

 

[Blue-Frog]

Ok Thanks. So would it pretty much be true that degassing is not a common commercial / traditional practice ?

Having made a few wines from scratch (not kits) then making one from a kit with degassing instructions, I felt some resistance/uncertainity to the practice.

Thanks for the tip about when it might be useful during active fermentation.

 

[jgmillr1]

Ok Thanks. So would it pretty much be true that degassing is not a common commercial / traditional practice ?

Having made a few wines from scratch (not kits) then making one from a kit with degassing instructions, I felt some resistance/uncertainity to the practice.

Thanks for the tip about when it might be useful during active fermentation.

No, de-gassing is not done commercially. Dissolved CO2 naturally will be evolved from the wine during aging or from the agitation during pumping&filtration. You can see the CO2 bubbles running along the inside of the hose after it's through the pump.

Honestly, I also doubt enough CO2 remains dissolved during active fermentation to shift the pH much lower since the pKa of carbonic acid is 3.6. The typical grape musts are run 3.2 to 3.6. Most yeasts are just fine down to at least 3.0. I've tormented yeast with cranberry wine at a pH of 2.4 and it still finished the fermentation, albeit slowly.

I suspect Blue-Frog is correct that the degassing instructions are designed to get the wine into the bottle quickly, especially if the wine is not racked enough times where it would naturally de-gas.

 

[jgmillr1]

Here is a picture of one of my small pumps with clear hosing that lets you see it de-gassing while it pumps. This was from a batch of recently cold-stabilized traminette.