In our vineyards in La Rioja-Spain, some time ago we could watch the "envero". It is a term used in viticulture referred to one of the most important stages in the grapes ripening. Basically it´s a change in the color; the red varieties change into a bluish color, and white ones turn yellow.
This change represents a transition to the end of the ripening, it takes place in the summer and can be considered the beginning of a countdown when we can start thinking about the harvest. That countdown depends on grape varieties, climates and weather conditions. Grapes, as they grow on the vine, are undergoing morphological and physiological changes that allow them to accumulate substances such as sugars and acids, primary aromas and some phenolic compounds that are the responsible of the color, taste and structure of wines.
Not much time ago, winegrowers tasted grapes from the vines after "envero". Valuing the sweetness and the acidity decreasing in grapes, they decided the best moment for harvest. Today, even without despising this technique, we can check acidity and sugar content in grape and we are able to decide more accurately, parcel by parcel, the begining for the harvest every year.
