According to Dr. Bruce Zoecklein, Head of the Enology/Wine Chemistry Group at Virginia Tech, wine can be broken down into the three sensory categories indicated in the table below.
Wine Sensory Components
Structure Texture Flavor
Sweet Light (delicate) Nutty
Acid Rich (dense) Earthy
* Found mainly in white wines
Source: Derived from Figure 1 of Matching Food and Wine.
As regards the structural components, Dr. Zoecklein argues that a balanced relationship must exist between the tastes of sweetness, on the one hand, and acid, astringency and bitterness on the other, in order to yield the perception of a quality wine to the taster. The preferred relationship is captured in his Palate Balance Equation (Zoecklein: Components of Red Wine Mouthfeel):
Sweet ⇄ Acid + Phenolics (Astringency and Bitterness),
Sweet = Carbohydrates + Polysaccharides + Ethanol,
Acid = Population of organic acids, and
Phenolics = Skin, seed, and stem phenols + barrel phenols + enological tannins + volatile phenols.
Based on the foregoing equation, an increase in the sweetness element of the equation will lead to a reduction of the taster's perception of acidity and phenolics; and the reverse is also true. Dr. Zoecklein sees this balance, or harmony, as a key indicator of wine quality and in that he is joined by Wines and Vines and Crushpad Blog among others. According to Chris Stamp, writing in Wines and Vines, "... a balanced wine is a wine in which the various components work together to provide a pleasing taste." According to Richard Leahy, writing in Crushpad Blog, wines that are in balance tend to stay that way while wines that are out of balance tend to grow moreso over time.
How does balance relate to quality? If, for example, a wine has insufficient sugar in relation to its acids and phenols, it will present as harsh and acidic and will retard the evolution of flavors in the mouth of the taster. A wine with too much sugar, on the other hand, will be flabby and cloying and will not refresh the palate. Such wines will not be perceived as quality wines by the taster.
Over the course of future blog posts I will be examining the components of the balance equation in greater detail in order to provide the reader with an understanding of the factors that the winemaker has to consider in his/her quest for balance, one of the key measures of a quality wine.