"Joe Sallustio" > wrote:

> I use carboys and no cooling, I keep 1/2" once fermentation is over.
> I just adjust the level with temperature variations, topping off or
> removing.

If I used no cooling system, and adjusted the level with temperature
variation, retaining a 1/2" airspace, I would be doing so from dawn to dusk,
as there is a 30-50ºF difference in outdoor temperature, depending upon
cloud cover. This translates to about a 10-20ºF fluxuation indoors without
refrigeration.

It seems to me that frequent (or even infrequent) removal of the stopper to
top up or remove wine would increase the degree of oxidation. If the stopper
remains, there is a finite amount of oxidation that can occur, because there
is a finite amount of oxygen in the airspace. When you open the stopper, and
especially if you remove or disturb the wine, additional oxygen will be
introduced.

However, it is my understanding, and fervent hope, that the amount of
oxidation that will occur with that little amount of surface area exposed is
not significant. Also, isn't some small amount of oxidation required for the
aging process? Isn't this why barrels and corks are designed to "breathe" a
bit?

I suppose both concerns (oxidation and thermal expansion) could be addressed
by using a larger airspace and filling it with CO2 upon racking?