I've always tested my red musts immediately after crush. While the SG, Brix, and pH tests seem to be valid, I'm starting to question my TA tests. I'm getting levels that seem too low (i.e. .30 or .40) when the pH's are in a good range. Then, when I wait a few days, the levels are often higher.
What do you do? Do you find that the TA's rise as the grapes break down? Perhaps there's tartaric acid in the skins that isn't assayed immediately after I crush the grapes? Lee