"Pete" > wrote:

> Is my acid of .675 anthing to worry about?
> My book says I can cold stabalize, and it might lower it.
>
> I will be putting it in my fridge shortly.
> I can leave it in there until the weather outside is colder.

Pete,

Is this a red wine or a white? The pre-fermentation "target" for reds is
about .65 TA and/or 3.4 pH. For whites it is about .70 TA and/or 3.2 pH.
However, anywhere in the .6-.9 TA and/or 3.0-3.6 pH range is still
"acceptable". Post-fermentation it is probably better to go by taste than by
numbers.

..675 TA is a bit high for a red, a bit low for a white, but I wouldn't try
to adjust it unless you are unhappy with the taste. A pH of 2.94 (which you
stated in your pervious post) is a quite low (i.e. acidic), but...

The acid level MIGHT come down significantly during cold-stabilization, IF
there are bitartrates that precipitate out. These will appear in the form of
a crystal-like sediment. If they do, you want to try to rack (after a few
months) without allowing the temperature to increase, as the bitartrates
will re-enter solution. So, get everything setup before you take it from
your fridge and rack immediately. Don't wait for it to reach room
temperature. The optimum temperature for cold-stabilization is supposedly
28-32ºF. Vibration from a refrigerator motor makes it less than ideal for
stabilization, but it's better than nothing. [If you have a camper or rv,
use its refrigerator, since it doesn't use a motor!]

Cold-stabilization may reduce your acid by .5-1.5%, and increase your pH by
..1-.3 points IF there is a substantial amount of tartaric acid. If most of
the acidity derives from another source (e.g. malic), you won't get much of
a reduction. Judging from your TA and pH measurements, I would guess you
have a lot of tartaric.

Malolactic fermentation will reduce acidity by converting the malic acid to
lactic acid. This can also give a substantial reduction, depending upon the
amount of malic acid in your wine. For more details of this procedure, go to
http://groups.google.com/groups?hl=e...fts.winemaking,
and search for threads on the subject. Or check Lum Eisenman's book:
http://home.att.net/~lumeisenman/chapt13.html.

If your taste tests indicate the wine is unpleasantly acidic now, you may
wish to add some calcium-carbonate or potassium-carbonate to reduce the pH
BEFORE cold stabilization. That is so the carbonate will precipitate out
with the bitartrates. If so, check the aforementioned links for details of
that procedure.

Isn't winemaking fun?