I know that you can't ever definitively state the characteristics of
wines as there are so many factors and subjective noses and palettes
on the subject. Saying all this, does anyone know of a resource which
attempts to list norms, usual values or recommendations of acid levels
for each country wine or classic grape wine?

I'm just interested in general. My specific concern is (as per my
reply to Jim's post above) for my Elderberry / Blackberry wines which
are all too acidic, a guide value would be very helpful as I attempt
to remedy the problem over 8 x 5 gallon batches...

Any help gratefully received as ever...