I'm not surprised at ernie's scenario... The CO2 has to dissipate by
diffusion through the airlock. This is a very slow process; petulance
in my wine takes about 1-1/2 to 2 years to dissipate under similar
conditions in a glass carboy. If this process wasn't so slow, you'd
also enjoy detectable oxidation of the wine during this time. The
process will occur more quickly in an oak barrel because of the higher
gas permeability of the wood compared to through glass.

(For you science nuts, both the CO2 leaving and the O2 entering the wine
through the airlock occur by equimolar counterdiffusion. Plus there's a
small boost in dissipation rate by expulsion during thermal expansion of
the wine.)

Gene

ernie wrote:

> The carboys are at a steady 55-60 degrees, under airlocks. I was surprised
> myself that the CO2 lingered so long.
>
> Droopy wrote:
>
>> ernie wrote:
>>
>>> I'll have to disagree with droopy. Even though I wait almost a year
>>> before
>>> bottling, from carboys with several rackings, I invariably got too much
>>> CO2 in the bottled wines before I started degassing. I use a
>>> bottle-brush
>>> in a variable speed drill once the weather warms up in May and yes,
>>> sometimes
>>> it foams too violently, which just means lower the speed for a while.
>>>
>>
>>
>>
>> huh, what temp do you keep your carboys at?
>>
>> I have never detected any co2 in wine over 6 months old at home.
>>
>
>