It is very difficult and unreliable to try to kill an active ferment. The
best way is to let the fermentation go to dryness. Once the yeast has gone
dormant it will all settle to the bottom. Then racking eliminates most of
the yeast form the wine. Once the yeast colony has gotten small enough you
can force it to stay dormant by additions of sulphite and sorbate. This is
only necessary if you are going to sweeten it back up.

If the fermentation sticks and you want to keep the wine as sweet as it ends
up, follow the same procedure, let the yeast settle, and rack the wine off.
But then sulphite and sorbate are a necessity rather than an option as if
you do not force the yeast to remain dormant, they may suddenly start up
again in the future.

You might try moving the carboy to a warmer area so it will finish up.
Fermenting slowly and on the cool side is generally considered a plus for a
white wine but may not be for a red.

Ray

"Serenity" <serenity@nospamserenitynyespam off.fslife.co.uk> wrote in
message ...
> My wine has been bubbling away since last autumn.
> It is still bubbling away.
>
> How do I know when to stop it fermenting and how do I stop it please?
>
> Also how can I be sure it has stopped, cos I bottled one lot and it blew
the
> corks out!!!
>
> Cheers,
> Serenity
>
>