This is a 'reciept' my gramma had in her book, and her twist was to cook the berries in the syrup on the stove until they started to thicken, then pour into a roasting pan and put into a 'moderate heat' oven (remember, she cooked on an old White Brand wood stove) and cook them, shaking the pan every 10 minutes until they were thick enough for her liking, and then she would process them in a canning kettle for 15 minutes. Once they went onto the shelves in her basement, everyone in the family had instructions to shake every single jar whenever they went down for anything for the first 2 weeks. They were always gone by Christmas. sometimes she added a cinnamon stick to each jar. Huge family, and she put these up in Quart jars.