Veraison in the Vineyard

In viticulture, we call the onset of the ripening of the grapes veraison (veh-ray-ZOHN, although around here you’re more likely to hear it pronounced ver-AY-szun. Get fancy and try pronouncing à la française, since the word originated in France). The official definition of veraison is “change of color of the grape berries,” but it is so much more than color change. Veraison in the vineyard signifies the shift from berry growth to berry ripening and maturation. Many developmental changes are about to occur!

[Side note: the word “berry” is used all the time in vineyard parlance, but may not be as familiar on the public’s side of the bar.]

grapes before veraison
Even your favorite red wines start as hard green berries

The vines change their focus from energy creation (photosynthesis) to energy consumption. They grow woodier in appearance as more energy goes into ripening the grapes. Veraison is just beginning in our vineyards and Winegrower, Ben Renshaw, starts paying close attention to berry size, texture, and taste because it means harvest is coming soon. We’re seeing red wine berries change from green to red or purple, depending on the varietal. White wine grapes also change color, but not in as pronounced a way as reds. The result is more golden.

Acidity in both red and white grapes decreases and the natural sugars increase. Aroma and flavor components are also developing, and regular sampling of the fruit from multiple rows of vines helps give an overall sense of what this vintage will be. Another change occurs in berry hardness. Up until now, the berries are very firm, but once veraison finishes, they are pliable and easily squeezed. Since white grapes don’t change much in color, this skin elasticity is a key observation in determining ripeness.

ben renshaw measuring grape sweetness
Winegrower Ben Renshaw using a refractometer to measure the Brix (sugar level) of our Sauvignon Blanc grapes.

Now it’s time to drop some fruit. It may seem counterintuitive to clip clusters of grapes to perish on the ground below, but it’s essential. The visual inspection and sampling mentioned earlier? From both of these processes, Ben can determine which clusters are the most ripe and sacrifice those that are likely to be less so at harvest. He ensures only the best grapes make it to the crush pad. Dropping fruit also helps to increase airflow among the clusters, allow more sunshine on the grapes, and prevent any number of disease pressures at this time, such as downy mildew. Once veraison starts and the grapes begin to ripen, it’s time to put up the bird netting. Birds are major predators of grapes, but raccoons, woodchucks, and deer can also take a toll on vineyard fruit.

Veraison is one of the most exciting and important times in the vineyard. And complex! There is so much more happening in both the vines and grapes than touched on here. In addition to the change in acid and sugar levels, the skin cells of the grape stop growing. The berries are now fixed in size, and that skin-to-pulp ratio is a big factor in the ultimate quality of wine. We remove the skins of white grapes during processing, but the skins of red grapes stay in contact with the juice during fermentation and are responsible for the color, aromas, tannins of red wine. Stay tuned for upcoming posts covering harvest at 8 Chains North!

For a deeper dive on veraison, check out this article from Cornell University’s Department of Viticulture & Enology.