Which Acid, and does it matter?

[Rice_Guy]

@BPL there are many factors affecting the final flavor of the wine.
One test that I have considered doing sometime is to add a sample of tartaric, malic, and citric acid each to a different sample of water. You could look up the weight of acid to use to provide the same amount of acid in solution (as measured by a TA test). Then you might add a little sugar and some vodka, exactly the same amount in each container. That might provide a way to taste the difference in flavor contributed by different acids in a simulated wine environment.

Acid chemistry is extremely complex in the real world. Every acid has a character called pKa which is a measure of how much is free H+ and how much is partially free as 'acid-H' or even 'H-acid-H' . pKa is the pH where 50% of the molecule can be found as free H+ (ie what your taste buds respond to) and 50% is bound on the molecule. An acid as malic will have two constants representing the two H+ ,, called pKa1 and pKa2.
All foods / wines are a mixture of salts which can separate into ions or remain as complexes. The ratio of mixture will influence each of the other molecules and how they behave. If it was easy we would have a numerical rule for acid addition instead of add half and then test, then recalculate estimated target. Another property is that as the crop changes / matures the ratio of acids change.

Distilled water is a good model system. Pure acids are a good model system.

Another complication is that there are other molecules which also react on the taste buds. ex a gram of smooth tannin will have an acid impact similar to twenty five grams of an acid. A hard tannin has too small a size to do this so it presents as a bitter flavor.