A few notes on measuring acidity and pH of wines.
At Vinmetrica, we get a lot of inquiries about the acidity of wines and how to measure them. We have a blog on pH & TA here (and followed up here) on our website wherein you can find detailed discussions about various aspects of this subject. Here I’d like to touch on a few of these.
pH vs TA
the term pH represents the concentration of hydrogen ion (” H+ “, also called hydronium ion H3O+), though to be exact it’s H+ activity that your pH electrode senses; see Q&A below). Titratable acidity TA, on the other hand, measures the total amount of hydrogen ion available in free and bound forms. pH and TA both correlate to the tartness of the wine, but the kind of acidity the wine exhibits is generally more a function of its TA value. The pH value is important for taste as well, but more important is its effect on stability of wine, from the beginning of fermentation through to the final product. Very roughly speaking, we want our whites and rose’s to be in the pH range 3.1 to 3.4, while our reds are usually best in the range 3.3 to 3.7. And in general we’re hoping that our TA values are going to be 6 to 7 for reds and 6 to 9 for whites. Note that pH and TA of wines do not track each other in any consistent way. For example it’s possible for a low pH wine to have a low or a high TA value.
Tips on Measuring pH and TA