Oh, ok.. So if you had 200 lbs of grapes initially. That would translate
into about 55 + liters of wine (using my pressing calc) and you added 136
gms of Tartaric or

136g/55 L = an increase in TA for the batch of 2.4 g/l at the most.

We'll have to wait and see how it comes out.. If your readings aren't
consistent you may need a new pH probe. When you titrate, you can use pH
meter to measure end point instead of color. Just add Sodium Hydroxide
until pH hits 8.2.. In the meantime, I wouldn't worry about, enjoy
fermenting your wine and the new perfumed air. Life is good..

-Jim

"David" > wrote in message
ups.com...
> Hi Bill,
>
> My initial calculations were incorrect.
>
> Part of the problem is that my first TA test was a bit inconclusive. It
> was done within 24 hours of intial crush, but by that time, colors were
> already clouding up the must, making it difficult to tell when I'd
> found the right TA level. Somewhere between .55% and .65%. It was
> pretty hard to determine exactly when the test sample turned gray, and
> not just a "tint" of gray.
>
> Another aspect is that I have two vats of must. One with about 16
> gallons, the other with about 5 or 6 gallons. Last night, the larger
> vat had much higher pH, because of more potassium being leached out of
> the extra pomace, while the smaller vat had consistenly lower pH (by
> .15!) due to less pomace.
>
> My challenge was to calculate the proper amount of Tartartic to add,
> understanding the smaller vat would need proportionately less than the
> larger, in order to achieve balance between the two. But then, I
> considered the fact that throughout ferment, the two vats will develop
> their own unique pH anyway, since there is more pomace in the larger
> vat, etc. So I ended up figuring that if the smaller vat were to have
> lower pH, and the larger a higher pH, it might make for a bit of an
> interesting blend once primary was done. And, even if the larger vat
> ended up with a much higher pH than the smaller vat, by blending the
> two after primary, I'd achieve a bit of balance.
>
> So. I added a total of 30.4 grams Tartaric acid to the smaller vat,
> about 6grams per gallon. This resulted in more or less a pH of 3.5,
> down from the 3.75. It was difficult to get an accurate read, as the
> acid was not evenly distributed throughout the solution, even after
> stirring for many minutes. I took 15 different samples, ranging from
> 3.3 to 3.6, 3.4 to 3.7, and in the end, averaged them all out to about
> 3.5. Depending on the accuracy of the TA test, this would put TA now at
> .8% to .85%, and while by itself, that might a bit high, it should
> balance out when blended with the larger vat.
>
> To the larger vat, I added a total of 136 grams of Tartaric acid, about
> 8.5grams per gallon. This reduced pH from 3.95 (it had gotten pretty
> high, even 4.00 in some portions of the vat) down to 3.8, and increased
> TA by .21%, to .76% to .81% (again, depending on the actual, initial TA
> test).
>
> I then averaged these out.
>
> 6gal. @ pH 3.5 + 16gal. @ pH 3.8 = 22 gal. @ pH 3.71
>
> 6gal. @ TA .82% (avg. of .8 to .85) + 16 gal. @ TA .78% (avg. of .76 to
> .81) = TA .79%
>
> These figures look fine to me. Even after Malo, if pH is boosted by
> .25, a final of about 3.9 should be fine, given the wine isn't intended
> for more than a few years' ageing.
>
> Fermentation is just 12 hours in, so if I still need to boost Tartaric
> a bit more, I could... I'm just questioning the need for it.
>
> Thanks again for all your helpful input.
>
> David
>
> p.s. the juice tastes great. I can taste the acid through the
> sweetness, so I think overall it's balanced.
>
>
>
> William Frazier wrote:
> > David wrote "I went ahead and have added more tartaric acid. From my
> > calculations,
> > the must should now be around pH 3.66 or so, with about TA .77%-.8%."
> >
> > David, did you actually take a pH reading? Ideally your starting pH
would
> > be low enough so pH after malo-lactic fermentation is reasonable.
> > Malo-lactic fermentation will raise pH by about 0.25 pH units.
> >
> > "For this second round, 61 total grams for the 20 gallons (~3g/Gallon,
> > or about .8g/L). Total Tartaric added was about 1.6g/L"
> >
> > If I follow your acid additions correctly you first added 3.0 grams per
> > liter tartaric acid to 20 gallons of juice. This works out to 227 grams
of
> > acid. Then you added 61 additional grams. A total of 288 grams acid
added
> > to 20 gallons (75.7 liters) of juice or 3.8 grams/liter. Add this to
your
> > starting 6.0 grams/liter acid and you may have an acid content of 9.8
> > grams/liter or 0.98%TA.
> >
> > How does the juice taste?
> >
> > Bill Frazier
> > Olathe, Kansas USA
>