Ripening group — wine grape

For wine grape varieties, the ripening group is determined by the period from bud break to harvest, measured in days or the sum of active temperatures. The classification includes groups ranging from very early (95–105 days) to late (145–165 days or more), with technical maturity defined by reaching optimal sugar, acidity, and pH levels for winemaking.

The choice of ripening group depends on the climatic conditions of the region: early varieties are preferred for northern zones with short growing seasons, while late varieties are effective in warm regions for sugar accumulation. This indicator is critical for vineyard management strategy, as grapes do not accumulate sugar after harvest, and the success of the harvest is evaluated via the glucoacidometric index.