Wash and remove stems from the cranberries. Grind in food processor. Put in large stainless steel saucepan with 3 cups water. Bring to a boil and simmer, covered, for 15 minutes.Strain thru 4 layers of cheesecloth. You need 6 cups of juice.

Add the juice to a large 4 to 8 quart saucepan.Add the sugar and stir. Add 1/8 tsp. butter. Place pan over high heat and bring to a boil, stirring constantly. At once stir in Certo then bring to a full rolling boil and boil hard for 1 min.,stirring constantly. Remove from heat. Skim off foam with metal spoon. Pour immediately into sterilized jars(see general directions for sterilizing and sealing).Fill to 1/4" from the top.Seal with paraffin wax as directed.

Yields 9 cups of jelly.