When Frontenac was first released in the mid 1990’s wine quality was the factor that drove it’s release. While it was good culturally being vigorous, cold hardy and able to bear well, and early reports on the wine were exciting, it had one outstanding weakness. In the Minnesota climate it was characterized by high acid. Although the sugar went over 20% easily enough, sometimes in August, the acid at this point can be 2% and more. We here at GRV learned to ignore the early high sugar and watch the acid as we rarely pick Frontenac before September 20th and like to leave them until the 25 or later, watching to see that raisining does not require earlier picking. Sometimes the berries do begin to dry up (raisin) but we normally schedule our Pick-your-own Frontenac day on the Saturday closest to September 20th and so far this has proven reliable.
By September 20th we expect to see sugar at 22-26% and higher but the acid still runs around 1.4%, usually slightly less. While this is rather high it is not unworkable and area winemakers have become adept at producing palatable and commercially successful wines from such grapes. In fact wine tastings and awards won suggest strongly that Frontenac has won a home here and is suitable to become a workhorse in the emerging industry.
Fruit Characteristics Chart
Plant Troubleshooting
Field Notes
