Assistant Winemaker Ronald Du Preez discusses the importance of veraison thinning grape clusters: dropping unevenly ripened grape clusters to the ground. Veraison, the color change in grapes, begins in July or August, depending on weather. In years with cool summer temperatures like 2010, it is very important to remove unripened and unevenly ripened clusters from the vines to balance their energy and ensure the best, most uniform grapes get fully ripened in time for harvest before the summer ends. Video recorded on the iPhone 4. Learn more on our blog: https://blog.jordanwinery.com/video-cool-weather-grape-veraison-and-thinning-fruit-before-harvest/.