Ray Calvert wrote:

> It is better to use an airlock. If by chance a little more fermentation
> were to take place or the pressure in the carboy increased for some other
> reason such as CO2 coming out of solution, it can blow a solid bung off and
> then your wine can be ruined due to oxidation.
>
> But I have a question. One of the things that need to be done after
> fermentation is to get the CO2 that is dissolved in the wine out. How can
> this be done if the wine is blanketed with CO2? Wouldn't the dissolved CO2
> just stay in solution? Partial pressure of a gas in solution is a function
> of the partial pressure of the gas in contact with the solution and the
> partial pressure of CO2 in the blanket would be very high.
>
> Ray
>

I'm guessing that the CO2 from fermentation is going to be largely
dissipated while you rack the wine (definitely while pressing the reds
after fermentation).
Re-blanketing with CO2 will raise the dissolved CO2 some (due to the
partitioning coefficient between CO2 in the headspace versus in the
wine), but will again be largely dissipated the next time you rack.

Gene