One of the most important moments in a grapevine’s annual lifecycle is the onset of ripening, when the grapes turn from green to red and naturally begin to sweeten. The French call this process veraison (“verr-ray-zohn”). Veraison also occurs in white grapes, but without the color changes–white grapes simply become more translucent.
Before veraison, wine grapes are small, hard, highly acidic, and green-colored from the presence chlorophyll. When veraison begins, the vine starts to transport its energy stores from the roots into the grapes. The chlorophyll is replaced by anthocyanins (red grapes) or carotenoids (white grapes), sugars, and other nutrients. After veraison, the grapes begin to dramatically increase in size as they accumulate sugars and start to develop aroma compounds. In addition, acid levels begin to fall in the grapes during this time. Acids continue to fall and sugars continue to rise until the grapes are perfectly in balance and ready to be harvested.
For winegrowers, veraison is an important time because it signals a change in the way they care for their vines. Currently in our vineyards, our Vineyard Manager, Miguel, and the team have started to trim bunches from each vine in order to ensure the remaining bunches receive more nutrients and sugars from the roots. Each region and each type of wine variety requires slightly different care to achieve perfect ripening.