Chapter 31

Evaluation of Wine Grape Maturity

Assessing Wine Grape Ripeness by Qualitative Parameters

In addition to using the quantitative parameters, the grape grower must become familiar with several qualitative measures in determining ripeness. Qualitative parameters of grape maturity include appearance of the grapes including the color and firmness of the skins, the appearance of the stems, the color and taste of the seeds, the taste of the grapes and the condition of the vines and leaves.

Soft Berries

Berries dehydrate slightly, and the texture of the pulp softens when grapes ripen.

Red Fruit Flavors

Under-ripe red grapes often have a green, herbaceous smell and taste reminiscent of asparagus or bell peppers.

Pulp Ripeness

Pulp ripeness refers to the gelatinous versus juiciness consistency of the pulp as well as the acidic versus sweet taste of the pulp.

Skin Ripeness

Early in the season, the tannin in the skins is harsh and astringent. Then, as the grapes ripen, the harsh, bitter astringency of the tannin diminishes. The quality and quantity of the tannins determines the structure, body, astringency, bitterness, dryness, and color intensity of the wine.

Brown Seeds

The color of grape seeds changes from green to brown as the berries ripen and should be brown, hard and have toasty (or at least nutty) aromas.

Clean Pedicel

When grapes are fully ripe, the pedicel (stem) can be pulled off the berry easily, and little or no pulp or skin tissue will be attached to the pedicel.

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