I was after concord grapes without seeds. Concord grapes are full of seeds and their skins are tough. That is why we see so much concord grape jelly and not preserves. The other stipulation I had was capturing that uncooked grape flavor. Nothing like making it easy. We started with green seedless grapes. We cut them in half and mixed them with concord grape juice. Then we froze them. When the grapes were solid we put them into the wide mouthed Virtis freeze dryer flasks we use with our rotary evaporator. We set the machine up and let the grapes cold cook. The vacuum removed the moisture. The freezing and thawing broke down the cell walls. The results were concord flavored green grapes. They were juicy, retaining a little of their snappy texture and yet soft and slightly jammy as you chewed. The flavor was bright and floral retaining the delicate flavor of uncooked grapes. Mission accomplished.