Process prepaired berries in food processor and put in jelly bag to drain. You will need 4 cups of liquid. To the liquid add the sugar and stir. In a large saucepan, bring mixture to a full rolling boil, stirring constantly.Add 1/8 tsp. of butter to reduce foam. Add 1 bottle of certo all at once,stir and return to a full rolling boil. Boil hard for 1 min.,stirring constantly. Remove from heat. Skim off any foam with a metal spoon. Pour at once into sterilized jars filling to within 1/4" of top. Seal with a 1/8" layer of melted wax. Cool and cover.Makes 8 cups.