Viticulture 101: Veraison in the vineyardViticulture 101: Veraison in the vineyard

Like wine? Want to better understand the winemaking process? Most winemakers will tell you that great wines start in the vineyard. So here’s your opportunity to learn more about how wine grapes are cultivated. In our Viticulture 101 series, we will explain the basics of the different growth stages, just as many of Oregon’s vineyards are experiencing them. Follow along as we walk you through the 2016 growing season.

After our last article on grapevine canopy managment, next comes veraison. In order to properly pronounce the French term that describes color change and the start of grape ripening, muster up your best French accent and say ver-AY-zhun. Much like tomatoes turning red, each grape in a cluster begins to change from green to purple during veraison. And veraison also occurs in grapes that don’t change color, including Riesling, Pinot blanc and Chardonnay.

All grapes begin as hard, bright green berries that look a lot like big peas. Once the vines hit the point of veraison, the unripe grapes begin to soften, becoming pliable and slightly squishy. White grapes transform into a lovely golden yellow and red grapes darken into shades that range from ruby-red to purple, depending on the grape varietal. As the grapes ripen, the individual grapes grow out of their crunchy, pucker-tart flavors into something that tastes more grape-like, sweet and fruity.

A complicated physiological process, grape skin cell division ends with the completion of veraison. This is essential because fewer skin cells means smaller berries and more skin cells will result in larger berries. Smaller berries make more concentrated wine, something every winemaker must consider as they plan for harvest.

It’s important to note that veraison marks the end of acid accumulation in the wine grapes. It’s as if a switch is flipped in each grapevine. Before veraison, the grapes built up acid levels and once veraison is over, the grapes concentrate on storing sugar, now using their acid reserves for energy to get them through the rest of the summer until harvest. Much like a bear stores fat for a long winter hibernation.

After the grapes have gone through veraison, many vineyard owners will remove any clusters that aren’t ripening as rapidly as the rest. The grapevines then focus their growing efforts on the remaining clusters and the picking crew will move through the rows more quickly if they have less fruit to visually sort and collect. With fewer unripe clusters making it to the winery, this practice can greatly speed up sorting lines as the fruit is processed.

For vineyard managers and winemakers, veraison also marks the beginning of an official countdown to harvest. Grape picking crews are notified of anticipated harvest dates and previous years’ wine is bottled so the barrels can be used again. Harvest interns are interviewed, empty barrels and fermentation bins are washed and everyone readies for the coming days ahead when freshly picked fruit will arrive at the winery.

The Willamette Valley is abuzz about veraison! You can find winery photos of Pinot noir and Pinot gris changing color all over Facebook, Twitter and Instagram. Visit again as we continue our Viticulture 101 series through harvest with a second peek into canopy management, coming soon.