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.
Physiological Ripeness: See Polyphenolic Ripeness.
Whole cluster: This can refer to whole-cluster pressing and/or whole-cluster fermentation, where pressing and/or fermentation happen without the stems having been removed from the berries. Stem inclusion can add more tannins and structure to the finished wine, but can also impart additional flavors. If the clusters are picked early in the maturation process, the greener, more flexible stems might impart vegetal or herbal notes. If the clusters are allowed to hang on the vine longer, given time to achieve full polyphenolic ripeness and lignification of the stems (turning rigid, brown and woody), the flavors imparted will be more mellow, earthy and spicy.