If it were me, I would add SO2 after crushing if cold soaking based on pH
level up to 40 ppm. Biggest thing I think you can do when cold soaking
though is protect must from oxygen exposure. Seal it off best you can. I
buy 1 gallon drinking water jugs from the market and drop those into the
must rather than dry ice. Mostly because they have strong plastic containers
and screw tops and I don't cold soak for more than 24 hours. I don't
actually cold soak red wine but do cold soak some white wines.. I think the
SO2 dissipates pretty fast and won't impact yeast after 24 hours.

In Bordeaux, by the way, they blend Cabernet Franc with Cabernet Sauvignon
to add color. Up to as much as one third is blended in.

My understanding is long skin contact at end of fermentation phase increases
tannin but not color and excessive contact may actually reduce color.

Another option out there.. Wine Labs, sells a pectinase enzyme, last I
recall from their catalog a couple years ago it was called "Rapidase
Ex-color". It doesn't add any color thats not present in the grapes
obviously, "..but aids in extracting pigments and stabilizing them in wine."
I've used it a couple times on Sangiovese. Don't anymore. It certainly
softened and broke down skins more than usual: however, since I didn't do a
side by side test can't be sure pectin had any affect at all.

> wrote in message
ups.com...
> LAst year I made Cab and it came out nice, but lacked body, and was
> lighter in color than I had wanted. This year I would like to change
> both of those things. This is what I was thinking, please offer advice.
> I was going to cold soak for 48 hrs with dry ice, but then I have been
> reading about extending the maceration. Perhaps I only need to do that
> rather than cold soak. - of course I have heard of both being done for
> Cab. If I do cold soak, do I need to protect the must from O2 as I
> would have to do for extending the maceration?
> Any other advice?
> thanks
> marco
>