Thyose are riparia grapes. They are very acidic and difficult to make
into a balanced wine. Early on they were used in hybrids becasue of
the extreme cold tolerance of the vines (up to -60 F I think). Baco
noir is a prime example of a riparia hybrid.

Many sources say to let the grapes sit on the vine until after the
first frost when they will sweeten. If you try that here you will not
see a grape that late because wild animals will get to them well before
that.

Me I have decided to use them for jelly and jam. Breeders have given
up on them too for hybridization I believe (IIRC this info is from The
American Wine Society Presents Growing Wine Grapes)