The grapes pressed about 8 gal. of juice. I really wanted 6 gallons
> but I picked too many grapes, they just looked too good on the vine.
> The juice is 15 Brix and a TA of over 1.60% . I used the standard
> small acid test kit sold in LHBS and had a hard time at the end of the
> titration because the test tube was full.
With a brix of 15, you would want to add quite a bit of sugar BEFORE testing the TA. But getting a 1.60% acidity down to acceptable levels is quite a trick.
Let's ameliorate it with water. So I added 2gal. water to 4 gals.
Seems a bit much! One part water to five parts must is the maximum dilution you can do without seriously affecting the flavour. Furthermore, when adding water, it should be sweetened to at least 20º Brix first. Then recheck your brix and acid.
Now I have 6 gal. liquid in a 7.5 gal bucket.
You need to allow at least 25% headroom, more with a high-foaming yeast such as Montrechet. Put the 6 gallons in a 10 gallon primary, or put 3 gallons in each of two 5-gallon buckets.
Also, I put 8 tsp. of calcium carbonate into each vessel.
I've lost track of your volume. However, CaCO3 is so powdery, that it cannot be measured with any degree of accuracy with a teaspoon. It should be weighed on a gram scale. 2.5 grams per gallon will lower acidity about .1%, but results can vary, so it must be rechecked. And you shouldn't use CaCO3 to effect more than a .3-.4% adjustment, or it can eat up all your tartaric acid, leaving you with apple-lemon juice.
Now my TA is 1.30%. Yes, my sodium hydroxide and color indicator are fresh from my LHBS.
Is it possible that you are not performing the acid test properly? Some instructions are quite confusing. If you've done this many times before, I apologize for the question. But it is a valid question for a newbie.
What should I expect as a TA for white grapes harvested in central PA?
Somewhere between .6 and .8 --- if the grapes are ripe.
I realize now that there are other ways like cold stabilization to
> lower TA but this is where I'm at. I'm adding sugar to the must in
> stages to equal a Brix of 22.
Cold stabilization (alone) won't bring a TA of 1.6 down to acceptable levels, and (if it really is that high) you've got to bring it down before you begin fermentation. I don't think your yeast will like the environment otherwise.
Please check the instructions for your acid test kit again, and run another test before making any more adjustments.
It is better to add sugar in one go, the amount being computed (or taken from a table) based on the starting volume and brix. If you add sugar, and then take another measurement, there will be undissolved sugars which will NOT register, thus giving too low a reading (and forcing you to add too much sugar). If you are fermenting on the skins, the liquid still in the berries will not be sweeted immediately, and the reading will be too high (forcing you to add too little sugar).