also on the Northern Grapes Website at http://northerngrapesproject.org/?page_id=802
News You Can Use
Grape Berry Ripening
Marquette clusters during veraison at Parley Lake Winery in Waconia, MN.
photo: Seth Reid
As we head into August, veraison will commence, and along with it, thoughts of when to harvest. A great deal of research has been conducted to characterize the ripening profiles of Vitis vinifera cultivars, which helps growers make informed decisions regarding harvest. However, little is known about the changes in chemical composition during ripening of the cold hardy cultivars.
Recent work at the University of Minnesota tracked changes in fruit composition of 11 cultivars, including seven cold hardy cultivars. The results are a good start to understanding more about the changes that occur in fruit chemistry as berries ripen. Included in this months’ News You Can Use are two publications that summarize this work; the first is “Understanding the Ripening Chemistry of Cold-Hardy Wine Grapes to Predict Optimal Harvest Time,” an article originally published in the August 2012 issue of Northern Grapes News. The second is “Fruit Ripening Profiles of Cold Climate Wine Grape Cultivars,” a research report that was written as part of the Year 2 Northern Grapes Progress Report.
Fruit Maturity Evaluation of Wine Grapes for Harvest Planning (http://www.extension.org/pages/33152/fruit-maturity-evaluation-of-wine-grapes-for-harvest-planning#.U9Kx2PldWJc)
Collecting Berry Samples to Assess Grape Maturity
Using a Refractometer to Measure the Sugar Concentration of Sap and Syrup (http://maple.dnr.cornell.edu/kids/refractometer.htm)
Chrislyn A. Particka, PhD
Extension Support Specialist
Department of Horticultural Sciences
630 W. North Street
Geneva, NY 14456