On Sep 22, 11:24 am, wrote:
> I'm using CV grapes...Syrah was TA .3 and PH of 3.84. Zin's were TA .2
> and PH of 3.83. All measurements done with an off the shelf new test
> kit and done twice. Actually I've used 2 new kits to get the same
> numbers.I'm totally stumped....I've adjusted by adding some tartaric
> acid and the PH has gone down to 5.5-6.0 but the TA is still off. My
> only guess is that the Sodium Hydroxide in these kits is wrong for the
> directions somehow......andy j.

Check the concentration (normality?), I've seen kits using either 0.1N
or 0.2N solutions, you need the right instructions depending on the
concentration. You can also just go by taste once you've made the pH
adjustment, lost of people just adjust for pH and don't worry about
TA.

Oh yeah, you can make a solution of tartaric acid in water, say 5g/L,
and measure TA on that and then adjust your results based on that. For
example, if your test gives you ~5g/L TA, then it's the right
instructions for your NaOH; if you get ~2.5g/L, then the instructions
are wrong but you can still use the test - just to multiply your
results by 2.

Pp