Polyphenolic Ripeness
Also known as physiological ripeness, is the concentration of polyphenols in grape skins, seeds and stems, in contrast to the traditional form of measuring ripeness based on sugar content (Brix, Baumé, Oechsle). It has become a trend among vintners to rely more on polyphenolic ripeness than on sugar levels in recent years, as polyphenols are the source of wine's color, flavor and mouthfeel. As grapes mature, particularly in warmer climates, sugar levels frequently rise faster than polyphenol concentrations. Leaving grapes on the vine longer to achieve polyphenolic ripeness has led to an increase in alcohol levels due to higher sugar contents, particularly in California.
