Lee wrote:
> This question gets increasingly complicated.
>
You're not kidding ...

> I often end up with wines that have pH's that are either too high or
> too low, and the best solution is to blend the two. My question is how
> to predict the resultant pH.
>
Sure, it can be done ...

> Obviously, pH is a log function, so blending equal parts of wines with
> pH's of 3 and 4 DOESN'T produce a wine with a pH of 3.5. A wine with a
> pH of 3 has 10 times the concentration of H+ ions than a pH of 4. Does
> anyone know of an equation to predict a resultant pH of a blended wine
> the following 4 variables:
>
> X = volume of wine with pH of A
> Y = volume of wine with pH of B
>
> My goal is to work backwards and aim for a specific pH, knowing the
> pH's of the original components and then calculating the necessary
> volumes of the two components. While bench trials are another
> solution, there should be some science to predict the results.
>
> Thanks for your help,
>
> Lee

pH = pKa + log([conc high pH]/[conc low pH])

http://www.changbioscience.com/calcu...asselbach.html

I'm an unemployed chemist, so conceptually, this is an easy topic for
me. But ...
1) You use conc of the acid and base, not the pH to determine how much
of each

2) You need the value for pKa, which is a constant. Now, that number
is published for citric, malic, and tartric acids, but what about the
other acids, and how much of each. You can't know this without an
expensive lab test.

3) Here's my question: Do you really need to get an exact final pH to
make the wine the proper flavor and stability?

I figure, you're just going to have to use trial and error to get to
where you want.