Notes from the Vineyard: what's this?

There's a fly in my Chardonnay.... er, a random white grape in my Frontenac Gris.

This guy popped up in random spots along our rows of Gris, exactly 25 of them with massive clusters of white grapes blushing into rich golds in the sun. (F. Gris on right, mystery grape on left.) I've been eating them every chance I get as they have everything I like in a grape - slighly sweet with a little bite but not too sour or acidic. They are starting to show signs of bortrytis, but what isn't this time of year.

I thought perhaps we made a mistake and put some Traminettes or Vidals in there on planting day, but the foliage, stem color and new shoots look nothing like anything else in the vineyard.

The clusters are massive. The vines grow just right. All of them survived the harsh winter and late spring frost. They are easy to care for with trailing growth and very few side shoots on their fruiting wood. The weird part is that none of them have experienced the lightning winter dieback that's hit everywhere else in the vineyard, where a vine will be growing along just fine and then realize that the winter injured the truck and it no longer can support growth. It's hit everywhere else in the vineyard except for these guys. So, they are super winter hardy. Also, they aren't pushing out new blooms all the time either like the Frontenacs.