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.

多酚成熟：也称生理成熟，它是通过测量葡萄皮，葡萄籽和果梗中多酚含量来衡量葡萄的成熟度，而非传统的通过糖度（百利糖度，波美度，奥斯勒度）来衡量葡萄成熟度。由于多酚是葡萄酒色泽、风味和口感的来源，因此近几年，更多的是依赖多酚成熟来判断葡萄成熟度，这已经成为一种趋势。当葡萄成熟时，尤其在气候温暖的产区，糖度经常比多酚浓度升高得快，葡萄则仍需要再生长更长的时间才能达到多酚成熟。但这样会使糖度继续增加，酒精度也会跟着增加，尤其是在加州。