"steve small" > wrote in message
...
> I am curious about Lums comments regarding O2 exchange, because it is
> precisely oxidation that concerns me - specifically with the frequency of
> opening the barrels to top them up.

I suspect that actually opening the barrel for topping contributes much less
significantly than the diffusion of oxygen through the staves. After all,
how long is the surface of the wine exposed during topping, and how big is
that surface? OTOH, the surface of the wine within the aggregate of all the
staves and heads is very much larger, and is exposed to air for the entire
time the wine is in the barrel. Also, since the wine penetrates to varying
depths within the staves the surface area exposed to diffusion through the
staves will be textured, and therefore have a much greater effective surface
area than the inside surface of the barrel.

> I have read that some wineries do not
> top up at all - they bung and roll the barrel to keep the bung hole wet
and
> then leave them for months.

That used to be more common when redwood bungs were still in use and before
the advent of steel tubing barrel racks, but there are probably still
wineries that do it that way with silicone bungs. I haven't seen rolled
barrels in quite awhile, and AFAIC that's not a desirable approach. I need
to keep closer tabs on the progress of my wines.

Incidentally, I remember that the Parducci winery used to bung barrels tight
and stand them on _end_ on stacked pallets! That would make me _very_
nervous.

Tom S