Concord grapes are very strongly flavored and have seeds. I made grape pie with some (no added sugar....and I used a soaked wheat crust with lard. When you juice grapes, you remove the skins and thus the fiber and the glycemic load shoots through the roof. Keeping the skins with them lowers it a bit. Pie will do this also with the added fat lowering the glycemic load further. Use only two cups of grapes or so per pie. Cut them with apples if they are too strong for your taste. Add butter, not sugar!) and froze the rest to add to mixed berry wine later when I have time to make it. I also have some bland raspberries and a bunch of elderberries in the freezer that will come out when I have time to make a five gallon batch.
You need to seed the raisins to make the pie. I think I posted the recipe and method in another thread recently. I know you said no pie, but really, it will be much better than juice if you are looking for a healthier way to consume them.
Or seed them and freeze them in small batches to add to other things like cobbler or crisp. I add raisins sometimes instead of sugar. I make apple-raisin pie without any sugar and it is divine!