"Rene" wrote:

Hmm, I tend to respectfully disagree with this too general statement.
It might be allright if you stick to grapes only but when making
fruitwines, or worse flower wines, the lack of buffer will greatly
affect pH.

1) I really don't know to which "too general" statement you are referring.

2) This subject was discussed extensively in a recent thread titled: "Value
of a pH meter", which you can read at
http://groups.google.com/groups?hl=e...m%26rnum %3D1.

3) The strong consensus of opinion in that thread, which convinced me and
reversed my previously held opinion on the subject, was "that the pH is a
much more important figure" as I stated above in this thread.

4) I don't recall you objecting to that opinion when it was presented by a
number of other individuals in that thread. Your participation and
contrasting opinion would have been appreciated (and still are).

5) I thought we WERE discussing grapes in this thread, a logical assumption,
since I don't recall another fruit being mentioned. In fact, I thought we
were discussing RED grapes, and thus the need for a diluent for the
titration.

6) I presented both opinions --- that adjusting pH alone would probably be
sufficient, and that adjusting TA alone would probably be sufficient. Is
there another method?

7) I qualified all my "general statements" by such prefixes as "the
consensus SEEMS to be...", " But if...", "Assuming the preceding discussion
to be correct...", "This procedure SEEMS to be much simpler...".

8) The entire discussion was in respect to pre-fermentation adjustments,
which (I believe) was the original poster's situation. In respect to post
fermentation, the consensus SEEMS to be that taste tests are of more value
than empirical data. I didn't mention this in _this_ thread, because I as
trying to respond to my perception of the poster's situation, and not go off
on a tangent as I so often do.

Just one example: Pear wine, following Lum's recipe. TA is adjusted to
0.65% . It's dry and the pH of this wine after a year still is (don't
jump) 2.7 . Taste is fabulous! And yes, the meter was properly
calibrated. In addition I can say that I have put batches aside with
lower acidity (TA 0.45%), pH also below 3 but clearly without bite.

Personally, I have to date been measuring and adjusting only the TA, and
assuming that the pH would be in the correct range (as it "usually" is, at
least with the fruit which which I'm dealing). This method and assumption
was based primarily on that stated in Jon Iverson's book, which didn't seem
to be contradicted in any other publication in my small library. And I
haven't had cause to regret the technique --- yet. Again, for
post-fermentation adjustments, I use taste testing AND measurement of TA.

The proponents of pH measurement in the aforementioned thread presented
compelling arguments to measure and adjust the pH and ignore TA, and made a
believer of me. Examples were given in that thread of acid being within
"acceptable" range, and pH being outside (albeit high pH, not low). The
consensus was that the acid should be adjusted until the target pH was
reached, and there was no reason to know the TA to do so. Again the
arguments were quite convincing.

If you disagree with this conclusion, I would appreciate a bit more detail
before I "waste" my money on a pH meter. In the above example, I'm assuming
you measured both values, but adjusted based on TA alone? Do you always do
so, in which case your pH measurements are (presumably) only to determine
the amount of sulfites required? Or do you sometimes adjust based on TA,
and sometimes based on pH, in which case when and why? Or do you somehow use
a combination of methods.

Or are you trying to make an entirely different point, which I have missed
completely.

So oversimplicity like saying pH is perceived acidity, therefore EQUAL to
your tastebuds is plainly wrong!

I made no such statement.

As a winemaker with only 5 years experience I think TA readings and
adjustments are an important reference tool to follow up recipes and
train your tastebuds for the right amount of acid, considering the
differences in base material. In that respect I think it's more
important than pH.

Thank you. It really seems that we are in substantial agreement, at least in
respect to post-fermentation adjustments.

Meanwhile, I think we are confusing the heck out of poor Louise. So, in
conclusion:

Louise,

1) you can use your mineral water for a diluent and proceed with your
titration as you originally intended, or

2) you can perform your titration with a pH meter accurate to at least +/-
..2%, by titrating to an endpoint of 8.2, and you won't need the diluent.

3) you can adjust the pH to 3.2 (for a white grape wine) or 3.4 (for a red
grape wine) or some other value(s) (for other wines), with a pH meter
accurate to at least +/- .1%, and you won't need the diluent or
sodium-hydroxide reagent.

Do whichever you prefer.