I’ve use Oenotools wine calculator app for my adjustments. I find it easier to plug in my numbers and get an accurate addition. I find that getting your pH, TA, and SO2 correct for the wine style you are making is necessary at a minimum of three critical points: At crush before fermentation, pressing, and bottling. Getting good numbers and making additions (if necessary) will help you avoid stuck fermentations, bacterial growth, and wild yeast from taking over. If you are more of a “natural” wine enthusiast, getting your fruit out of the vineyard with good numbers is your best approach.