2019 grape maturity testing

By Terence Bradshaw

September is here, and grape harvest will soon be ‘on’ in Vermont vineyards. While the spring was generally wet overall, diligent management should have left you with relatively disease-free grapes and vines. The dry, hot/warm weather since July has been great for grape maturity, but these recent cool nights are likely to slow development.

This year, we will once again be posting fruit / juice maturity values on the UVM Fruit Program website. Watch for that link in the next couple of days, as I just switched computers so still have to load my web editing software. Until then, I am posting a snapshot of the data below. We don’t have all of our cultivars here yet, but you’ll notice some new ones from our new NE-1720 cultivar evaluation trial. We may pick Brianna next week, but the rest have some time to go.

9/9/2019 Brix pH %TA (g/100ml)
Briana 16.2 2.92 0.83
Louise Swenson 17.7 2.97 1.07
Crimson Pearl 19.0 3.02 1.36
Itasca 23.0 3.11 1.19
Petite Pearl 17.7 2.99 1.15
St. Peppin 18.3 2.98 1.50
Verona 15.9 2.78 1.63
Data collected at UVM Horticulture Research & Education Center Vineyard, South Burlington, VT. Accumulated degree days (base 50°F, BE model) since April 1 = 2118.

How do you assess grape maturity using juice data? Please see our relatively new fact sheet, Pre-Harvest Winegrape Juice Testing. That sheet also contains some target values for when to harvest each of the winegrape cultivars in our vineyard.

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