Boof,
If you look at the pH curve for a cheese from beginning through aging, you will see that the pH actually starts to go UP shortly after pressing. Generally, as a cheese ages, the acidity becomes less and less. The specifics and timing depend on a number of variables during the make. For example, if you drain too late, the curds will develop more acidity which translates into a sour, acidic cheese - UNLESS you let it age longer, sometimes MUCH longer. But most "sour" cheeses can be cured with more aging.
