I've been conversing with a gentleman from New Zealand, Dr. Johan Van Schalkwyk (a PhD chemist) for over a year now, and as a result he has developed a program for predicting wine acidity changes.
The program asks you for the existing TA, pH and SG values, as well as an estimation of the existing acid composition (malic, lactic, succinic, citric, acetic, tartaric), it asks you for the desired pH, and then predicts how much tartaric or malic acid to add to achieve that goal, and what the TA will be depending on what proportions of tartaric to malic you add. If you need to raise the pH, it will predict how much potassium bicarbonate to add, and what the TA will be after the addition. If you expect a malo-lactic fermentation, it will predict the ending TA after the MLF.
There have been several books written which include analysis of wine acid compositions, which can be used as guides if one lacks the laboratory facilities for an exact analysis. (As a home winemaker, I do not have access to these facilities.)
We think his new program is ready for some critical review. Please check it out at:
Dr. Schalkwyk has been very helpful, and would be willing to work on improving this program (when he has the spare time!).
For some interesting background into what makes Dr. Schalkwyk qualified to write such a program (he is not a wine maker), check out this link:
Please let us know what you think of his program!
Regards,
John Wiedenheft