Grape maturation state

The definition of maturity, the biochemical transformations of grapes during maturation and related subjects have been described in Chapter 10. Grape maturity varies as a result of many parameters and is not a precise physiological state. 

This notion of anthocyanin extractability depends on the state of maturity that controls the breakdown of skin cells (Table 6.15). All other conditions being equal, when grapes are perfectly ripe or slightly overripe, the anthocyanin content in the wine is higher than it would have been prior to maturity, although these pigments tend to decrease in grapes. Both color and total phenol content are at a maximum. 

The organoleptical quality of tannins is directly related to maturation conditions. Enologists have defined this quality in terms of good tannins and bad tannins. The chemical understanding of these phenolic compounds has made it possible to make a better choice of winemaking techniques that optimize the quality of various kinds of grapes. A perfect state of phenolic maturity not only supposes a maximum tannin concentration it also corresponds to soft, non-aggressive, non-bitter tannins. 

In certain years, grapes may have a homogenous maturity and perfect sanitary state. In these situations, all of the grapes can be harvested at the same time—multiple harvesting is not necessary. 

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