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 20^th 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 20^th and so far this has proven reliable.

By September 20^th 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.

Even so, an amazing thing happened at our vineyard this past summer. Steve & Bonita Patton, owners of Post Town Vineyard & Winery soon to open west of Rochester, had asked for part of our 2004 Frontenac crop and we had gladly committed it to them. One day just before mid-September Steve stopped by and wanted to come up and see his grapes. We had the block trained in two ways. The first grapes we planted were on a High Wire Renewal System wherein we pruned to spurs off a cordon on a high wire 6’ off the ground. From these fruiting spurs long, vigorous typically Frontenac-like shoots grow upward and then droop down. They can be unmanageable often becoming tangled and dense, clearly a weakness of this system.

We had room to plant 150 more "Fronts’", as we call them, to fill out the block, and since they clearly had sufficient upward growth character, we decided to try it on the mid-wire renewal or Vertical Shoot Positioning (VSP) System. We have become pleased by how easily Frontenac is trained to this system and how orderly the vigorous growth can be as it goes directly upward attaching to "catch-wires" above and then is hedged off as it begins to droop downward from above the top wire. We have also been pleased by the ease with which the crop is picked as it is on spurs on and near the mid wire about 3’ off the ground. We have come to believe this is a superior way to train Frontenac and Frontenac Gris as well.

As Steve and I approached the vines in question, however, I noted something I could not believe. The raccoons had been eating the Frontenac trained on the mid wire renewal trellis. Since every grower knows that raccoons will not eat anything the least bit tart and that Frontenac before mid September is exceedingly tart what was happening here was outside of my experience. I am sure Steve thought I was seeing an extraterrestrial for my open mouthed amazement.

We tasted them and indeed they tasted very sweet and rich. The acid was hard to detect. I looked over at the older Frontenac on the high wire renewal and not a grape was touched. We tasted them as well, and recognized the sharp familiar acidic tang. These were typical Frontenacs but the ones on the mid wire were ripe and sweet and ready. Indeed if we didn’t get them picked soon the raccoons were ready to take the whole crop. Within a day or two I had organized a picking crew and we took what remained of the Frontenac on the mid-wire. It was rather disappointing as we had expected to get 1000 lbs., perhaps 1500 lbs. off these young grapevines but we were lucky the creatures left us the 500+ lbs. we did get.

Even more amazing was what Steve told me a few days later. The juice from these Frontenac was very dark when pressed, notably darker, he said, than the Frontenac received from other sources and in seasons past. More interesting was that Steve found that the mid wire Frontenacs were at 24% sugar (not untypical) but the TA was .77 (not at all typical). Since we feel fortunate to see Frontenac at below 1.35 TA this was amazing. Steve said he had tested several times and then in his disbelief bought another acid test kit to try again. The results were all the same. The total acid on these Frontenac were at .77, perhaps a bit low for us northerners to deal with.

If, using the Mid Wire Renewal, we can get Frontenac to drop their acid reliably it will be of enormous significance to northern growers. Can we replicate this experience year after year? We do not know. Will the wine made from such grapes be better than high cordon grapes? Only time and experience will tell. However, a bottle of Frontenac made by Steve this fall from these grapes was dark and rich although Steve had made it like a rose’ without skin time in fermentation. Although bone dry it lacked the bite of acid so often seen in Frontenac wines from this clime. Steve also took a bottle of this wine to a winemakers roundtable recently. There was unanimous amazement not only regarding the numbers achieved but of the smooth rich character of the wine. In fact one local winemaker who has made several vintages of Frontenac could not believe this wine was made from Frontenac at all. (It was!)

We do know that Frontenac adjusts to the Mid Wire Renewal System very well, grows in an orderly fashion and is very easy to pick. We think that the fruit down low on the leaf canopy and lacking the shade from layers of leaves often seen on the high wire system is a great advantage in ripening and may be the key. We also see that hedging of the fruit zone along the mid wire would be easy and is a common practice with this system in the eastern U.S. whereas hedging the jumbled canopy of the high wire is essentially impossible or requires laborious hand removal of leaves.

At this point two observations seem appropriate. 1. Chris Lawler of the Lawler Family Winery at Galena, Illinois reportedly deducts a penalty for Illinois grown Frontenac that has a TA over .9%. While we here in Minnesota have rarely seen acids on Frontenac this low this illustrates that Frontenac will drop acid reliably under the right conditions. 2. Since we have observed Frontenac sugars going over 20% in August, we feel that if the acids can be dropped reliably early on, Frontenac may become an early ripening grape rather one that just barely makes it.

In any case, in our minds the mid wire renewal is better for Frontenac than the High Wire or High Cordon System or the Four Arm Kniffen. Even if the acid reduction is not reliably replicated the growth pattern adjusts easily to this system. From now on at GRV all Frontenac and its color mutation Frontenac Gris will be trained using the Mid Wire Renewal System and we would recommend it to other growers as well. Will it also solve the Minnesota Grown Frontenac’s chronically high acid levels? It is exciting to think that this may be so! Only time and experience will tell.