Bob wrote:
> I am trying winemaking for the first time with plum wine, due to
> this years great harvest. Would it have the same benefit to flush
> the top of the carboy with CO2 instead of topping it off after
> racking?
>
> Bob
>
>
Yes, you can do it that way, but it's harder to be sure you've got the
airspace purged of oxygen than by just topping it off.

Since CO2 is heavier than air, you want to use a fill tube which goes
down almost to the level of the wine. Purge with the CO2 with at least
3 times the volume of the airspace. Don't purge too fast; slower is
better so you displace the air rather than just mix it up in the carboy.

Another way of purging the headspace is to drop a few chunks of dry ice
into the wine, cover the opening lightly and let the sublimating CO2 do
the air purging for you. This only has the disadvantage of the dry ice
giving off cold CO2, so you get condensation in the airspace. Doesn't
affect the displacement of the air, though.

Gene