“Do these grapes have a problem?” asked my friend. “They are changing their color not uniformly, but berry by berry!”, said, showing me the bunches of Cabernet sauvignon grapes turning their colors from green to purple. It was his first time to see the grapes during “veraison”.

Veraison is one of the most spectacular times of the vineyard, when the berries start to change their color from green to yellow or purple/red. Although they are sharing the same rachis and they are a member of the same bunch, each berry changes their color individually.

This year Cabernet Sauvignon in Napa showed its first purple colored berry in the second week of July. When half of the bunches in a vineyard plot show signs of color change, we can say that we have veraison. The grape growers keep these dates recorded. It allows them to keep up the progression of the season, compare with the previous vintages and predict harvest date. The weather in the following days will have an impact on the harvest dates, so we will wait and see how mother nature collaborates with us this year.

One of the most important factors affecting veraison dates is the grape variety. Actually, all the phenological stages of grapevine are variety dependent. To classify the varieties according to the time of phenological stages, we use Chasselas grapes, a standard variety. The ripening date for Chasselas is accepted as August August 14^th and is used to compare the average ripening date of the other grape varieties. The varieties that ripen earlier than Chasselas are called early ripening variety, while later ones are called late ripening variety. It means early ripening varieties will have all the phenological stages, bud break, bloom, fruit set and veraison earlier as well. In the case of Cabernet Sauvignon, it’s a late ripening variety generally ripening three and a half weeks after Chasselas.

Last year I was in Bordeaux to experience veraison which started at the end of July-beginning of August for Cabernet Sauvignon. Read more about it on Veraison in Bordeaux.

It’s hard not to be mesmerized by the beautiful colors in the vineyard during this period. I had a chance to make daily observations in Cabernet Sauvignon grapes between July 18^th and August 2^nd. In the following photos, you’ll see the daily transformation of four bunches, and appreciate the random color change of the berries.

Cheers,

Nesli

All images © 2016 by Wines of Nesli. All rights reserved.

Categories: Vineyards