Those look like the wild grapes we in the midwest used to make wine out of.
They are very highly colored as they have dark red juice and are high in
acid. We would press the juice and use a gallon of it to make 5 gallons
of wine, and on some batches we would also press elderberries and use a
gallon of elderberries and a gallon of the wild grape juice to make a 10
gallon batch adjusting the SG and acid to normal parameters. This would
give a fairly well balanced wine, as the high tannin in the elderberries
would be reduced to a more moderate level.