About 5 years ago I purchased a small property in Saltair. Among the 3m high Himalayan blackberries a grapevine had found its way up a bigleaf maple sapling. The seller informed me that the grape was good for dolmades, but not for fruit. The property was originally developed in the mid 60s and I suspect that the grapes were planted around that time. As I cleared off the land for my garden, I retrieved some of the rootstock and planted it along a fence where I wanted it to grow. It gets full sun, but is on a 9% NE slope. The plant grew well and after 3 years produced a few grapes.In subsequent years the vine florished and currently,(5th year) produces some 25lbs of green grapes. Although, understandably, the grape struggles to ripen, ripe grapes, evidenced by a yellow colour (vs the hard green of the unripe ones), have a great full sweet muscate flavour. The berries are upto 20mm in size with 1-4 pits. The skin is firm (good if you like to chew on them) and separates readily from the gel-like flesh (slip-skin?). The bunches are compact and of convenient size. The leaves are shallowly 3-5 palmately lobed and about 18-20cm wide and slightly longer. I found that placing the grapes in the fridge for about 6 weeks further ripens the berries (they also dry out a bit). I have include a couple of pictures. Can someone tell me what species/variety of grape this is and offer any advice on how to manage it? Is this one of the north american rootstocks or is it a cultivated variety? Are there cultivation issues to watch for or is it quite hardy? What can I do to overcome the marginal heat units of the NE slope?