The pH scale measures how acidic or basic a substance is and ranges from 0 to 14. In wine the pH range is typically between 3.0 and 4.0, with an optimal range for whites around 3.2pH and reds 3.5pH. Wine pH could be interpreted as how acidic a wine might taste…but this is only a partial explanation of the effects of pH in wine. A wine near the high end, at 4.0 may be flat or flabby and have a “soapiness” to it. High pH wines tend to age poorly and harbor nasty critters who contribute to wine flaws and eventual faults. Low pH wines tend to age better but may be too acidic to drink! I think pH is the single most important aspect of wine making. It determines sensory attributes, sulfide capacity, spoilage capacity, color and oxidation capacity.