My great aunt has a vineyard with about 15 grape types and my mom has two different grapes planted at her house as well. Since it's warmer on the trellis at moms and sheltered, the grapes do better there in bad years. Spring lasted through June this year so grapes weren't as good. Got about 60 pounds from mom. One year we brought back 300+ lbs from my great aunts. Some white and purple concords, muscats, a pink table grape and some purple wine grapes. Hubby loved those wine grapes for just eating. Those ripen earlier than the other grapes so I should get a few starts and see if we can get fruit here.
Mom made grape jam many times growing up, but I don't care for the skins in it and we had an issue with the tartaric acid forming crystals in it. Probably had to do with the grape variety, but the skins do have more of it in them. I prefer to juice the grapes and let them set a few months for the crystals to settle out, then I make jelly. Concords and Muscats have seeds as well. Got to get those out. Those suck in raisins, too.
Mom made raisins out of the seeded grapes many times. One year she went overboard on the raisin making. I mean WAY overboard. I think we had a few hundred pounds of raisins when she was done. She didn't make any for years after that. She found a sealed container of them in the back of one of the closets a few years ago. Nothing like 20 year old raisins. They all looked and smelled fine, and I got brave and tasted some and they still were better than store bought.
I have a dehydrator myself now, and if we get a good year of grapes again, I'll make up some raisins. Last year was a dud because of the cool weather. Even off mom's big vine we only got maybe 20 pounds. Mom keeps the vines to shade the south side of the house in summer. Helps them a lot on cooling by keeping the sun out. Normally they would eat some of the grapes, but most of them would get cut off and taken up to the cabin to feed to the deer. So I get calls saying "the grapes are ripe, come get them", now.