Dear 100 Hour Board,
A long time ago (in the 80's or 90's) the Bishop's Storehouse had sizeable cans of dark grape juice with a recipe for grape jelly on the paper label. I believe the recipe only involved the grape juice, sugar, and boiling (to thicken it). There was no pectin, and it didn't take long to make. The sugar it used was plain old white sugar. I know it worked, rather well, because I tried it more than once. If you boiled it too long, it would thicken so much that it would be difficult to remove from the pan, like firm toffy or something (but it tasted amazing either way). However, I've since lost the directions and proportions, and I haven't been able to replicate the results. I haven't even found a similar recipe online, nor have I found grape jelly that tastes similar (although I was already familiar with the taste from other stuff back in the day, somehow).
So, what is the recipe they used? I'm hoping you can somehow get access to it.
I wish you asked this over Thanksgiving break, because I'm going to my grandparents for Thanksgiving and they have super old cans in their food storage. My cousins and I found one that expired in 1993. Who knows, maybe I would have found this as well.
Unfortunately, I was unable to find what you're looking for. The closest thing I could find was this, though it does use real grapes instead of just grape juice.
If anyone has any ideas please leave a correction!
-guppy of doom