I grow strawberries, blackberries, currants boysenberries and raspberries. Once they are ripe what doesn't get eaten goes into the freezer for smoothies and jams! I put berries into a pot with some sugar, about 1/2 sugar ti every 5 cups of berries. Or less if I'm making it for my neighbour as he doesn't like it too sweet. I boil the berries and sugar slowly for around 1/2 hour but check consistency around 20mins. I continue to boil while keeping an eye on it, still stirring frequently, until the fruit is thick, about 30 minutes, then put into prepared jars. Soooo good!