Grape Jelly (No Added Pectin)

My husband planted a purple grape vine the year before we were married and we harvested a ton of grapes this year. It was a lot of work, but really great to get all these delicious grapes from our own yard. I believe it is a Concord grape vine, but not positive about that. The plant yields small, round, dark purple grapes with one or two seeds. The grapes themselves are sweet although the skins are a bit tart.