PH
A chemical measurement of acidity or alkalinity; the higher the pH the weaker the acid. Used by some wineries as a measurement of ripeness in relation to acidity. Low pH wines taste tart and crisp; higher pH wines are more susceptible to bacterial growth. A range of 3.0 to 3.4 is desirable for white wines, while 3.3 to 3.6 is best for reds.