"LG1111" wrote in message
...
I'm embarrassed that every year I have the same question, and it still
doesn't
make sense.

The grapes that I can get here on the east coast are usually overripe
Central
Valley California grapes. Invariably, they have low acid levels. But I
just
tested a sauvignon blanc batch that had pH levels in the 3.2-3.3 range
(tested
with 2 different recently calibrated meters) and TA levels in the .50
range. I
tested the TA's on freshly pressed juice, using a titration method with a
color
indicator. I even verified the titration using the pH meter and waiting
for a
pH of 8.2 as the titration progressed, and the TA of .50 is valid. I
guess my
NaOH standard could be off, but I doubt it.

So this is the question: How can there be that much discrepancy between
TA and
pH? I can't see adding tartaric acid to a must that has a pH of 3.2.

What would you do?

I'd leave it as is and ferment it. Trust the pH. Ignore the TA. Sounds
like the grapes are low in potassium.

Tom S