I wonder if we, as winemakers, make too much of manipulating the must/wine instead of just gladly accepting what nature presents us. This notion has been at the forefront of my thinking the last couple of days…
Neither extreme is the best choice -- as Oscar Wilde said, "Everything in moderation, including moderation.”
Nature's bounty "as is"? I correct extremes that will negatively affect the fermentation and/or final result.
Brix is the easy one -- if the brix is too low, a weak wine is produced that may not have a good shelf life. Too high? The wine is unpleasantly hot. Correcting brix is easy and has few unhappy side effects.
TA/pH? This is a tougher one -- if the values are way too high or low, adjusting makes sense, else the wine may not ferment or may not be shelf stable. Adjusting acid up and down makes sense if extremely off, either high or low.
On the other side of the coin, focusing on individual numbers to fine tune the wine leaves out too many critical factors that we are unable to understand, much less control. The lack of correlation between TA and pH is a good example.
My changes to your batches?
4, 5, 6: water back to 23.5 to 24.5 brix.
4, 6: reduce the pH a bit.
Post fermentation -- taste the wines. Add tartaric little by little over succeeding months, letting the acid integrate with the wine. Base additions upon taste, not a pH meter (the pH meter will not drink the wine).
Keep in mind that the enemy of "good" is not "bad", the true enemy is "better".
