Bill, thanks for all your help. I had to recheck my notes over the
weekend. First, I had not data from the producer - this juice came
from a grower, via a home brew shop connection. The grower crushed and
pressed and also added bentonite, as I found out after defrosting.

According to my notes, I defrosted the juice in warm bath, mixed and
measured Brix, pH, and TA. The TA came at 4.1 g/L, pH 3.51. I added
40g tartaric - estimated the juice volume to somewhere between 20-22L,
so ws aiming for around 6g/L. Mixed and put in fridge for a day to
settle. Next evening remeasured pH and TA - 3.21 and 6g/L. The TA
looked bang on but still low, so I added another 10g/L, bringing the
estimated total to 6.5g/L (didn't measure after).
Next, I racked the juice off bentonite and added yeast starter.

So, that brings me to the point. The juice was cold but unfrozen for
more than a day. Also, any bitartrate should at that stage have been
in the bentonite sludge, so I'm not sure if the freezing had any
effect on the *measured* initial TA level.

Anw, I think we can close this off now; I'll just watch this more
closely in the future. I totally hear you about this hobby/passion
being a constant learning experience. I don't think I've ever made a
wine without one or more "blunders" in the process - as the knowledge
grows, they just become more esoteric It's fascinating.

Til later,

Pp



"William Frazier" > wrote in message >...
> Pp. - I should have asked first if the company you bought the juice from
> gave you starting Brix (or S.G.), pH and TA test results? If so how did
> these numbers compare to yours?
>
>
> I don't know how long it would take for acid to redissolve. It's not
> instantaneous. If I suspected acid had precipitated out of solution and I
> was real concerned about knowing the actual starting TA I would do one of
> the following;
>
> Let the juice warm to room temperature and stir it up real well. Take 4 or
> 5 samples from different places in the juice. If the juice is very well
> mixed the test results should be close even if all precipitated acid is not
> totally dissolved.
>
> As an alternative you could decant the juice off any settled material. This
> way there would not be anything to redissolve. Then after testing you could
> adjust TA and be confident you have a valid starting number.
>
> Also, for
> > clarification - I'd need to take the several samples over some time,
> > right, otherwise I'm just measuring whatever the acid level is at the
> > moment, no?
>
> No. You want to know what the acid level is at the moment before you start
> fermentation. Take multiple samples so you know if the TA is uniform across
> the batch of juice. Keep in mind that I'm the type of winemaker that does
> lots of tests, so I can better understand what happens in the winemaking
> process. I enjoy the testing and all other aspects of winemaking. The more
> I learn about wine the more I need to know.
>
> Bill Frazier
> Olathe, Kansas