If we assume it's CO2, either left over from ML or otherwise dissolved
in the wine, you've got the same problem as if you wanted to
flatten/de-fizz a bottle of cola. Shaking is not good for the wine,
though, so you need another way.
The inner surface of the carboy is likely too smooth to have spots
where the bubbles can form, but if you put some inert material with
texture in the carboy, so that the fizziness has a spot to become
bubbles, it might de-gas itself over time. Maybe a stir-stick, or a
plastic rod that's been lightly sanded (and cleaned really well).
You'll have to do it in such a way as to be able to retrieve it later.
Perhaps a fining agent, like bentonite might work as well.
You could also warm up the wine, though to get enough help for the
fizziness, you might end up cooking the wine first. A rough racking
would de-bubble it as well, though I wouldn't recommend it at this
point if you're hoping for a drinkable wine. :-)
> I still have a batch of merlot that I emptied out of bottles and put back
> into a 3 gallon carboy because one bottle popped its cork, and other bottles
> I opened I discovered a fizzy, ***ly Merlot....
> I had it in the 3 gallon carboy perhaps 2 months or so, hoping it would fizz
> out by now, under an airlock...
> But when I went to taste and try it today...still fizzy, still ***ly
> what do you think is happening?
> still fermenting? I thought at one point it had already been finished.
> ML fermentation?
> The merlot tastes good (from a juice from Ontario I bought)...
> just....can't bottle it again/yet...
> Any ideas of how to treat it?