Definition - What does Phenolics mean?
Phenolics, often referred to as phenols or polyphenos, are the elements behind the red color of red wine. It is an organic compound released by plants and animals as a part of their defense mechanisms with a central cyclic benzene ring and a varying number of hydroxyl groups as substituents. So, the more stressed the vines are, the more phenols they will produce. Phenols not only affect the color in red wines but also act as preservatives and affect the taste of wine. Phenolics used in winemaking are subdivided into two different groups: non-flavanoids and flavanoids.
WineFrog explains Phenolics
Almost all the phenols used in winemaking are derived from grape stems,
Phenol concentrations of a particular variety can be changed and manipulated by different methods and the manipulation can completely change the flavor and quality of the produced wine. Red wines are rich in phenols from the skin and seed of the grapes, whereas white wines are rich in the phenol that originate from the pulp of grapes. Tannins, the most common and important variety of phenols, are responsible for the aging potential and the structure of wine. Tannins also react with anthocyanins to provide color stability in wine.