Stir until liquid then over a low heat bring to a slow boil. Stir very little while cooking. Cook until half tsp of fudge dropped in cold water forms a soft ball. (About 7 -8 minutes). Take from stove and add vanilla and margarine. (For Jan's add Peanut butter). Beat until it is about the consistency of Pudding. Pour into a greased 8 x 8 pan. When it is almost firm mark your cuts. When cool finish cutting and remove from pan. Enjoy. This recipe was used during World War 2..for sending to the US Marines fighting overseas.. It was canned and they opened it like 'cranberry jelly' and sliced it into pieces. Recipe from Agnes Gibbs local 'Radio Personality' 1940 Portland, Maine Shared by Jan Cargill, Prodigy ID# VHPK03A.