james wrote "Does the acid level always change as the must ferments? Does it
increase or decrease? Do most folks adjust the acid level of their finished
wine according to taste or the acid test after the wine is finished?

During fermentation succinic acid increases but this acid is in very low
concentration. Tartaric acid may precipitate out of solution as the
fermentation goes along especially if temperature is cool. Malic acid can
be changed to lactic acid by ML bacteria and this will lower the acid
concentration. But my experience is that acid concentration tends to
decrease over all when fermentation is complete.

Use your taster first to decide if the wine has too much acid. If it's too
tart, depending on the wine, you can add a little sugar. If it's really
acidic tasting do titrations to find out how much acid is in the wine and to
guide you on acid removal. If it's flat tasting do titrations so you know
how much acid can be added without over doing it.

Bill Frazier
Olathe, Kansas USA