Plum-Port Wine Jelly

Preparation Pit the plums. Tie the pits in a cheesecloth bag. Cut the fruit into quarters. Simmer the plums, pits and water in a covered saucepan over medium heat for one hour, or until the fruit is almost reduced to a pulp. (To hasten the process, mash the fruit coarsely after it has cooked a while.) Discard the pits and force the pulp through a coarse sieve or a food mill. Place the purée in a jelly bag and let it drip overnight. (If you do not have a jelly bag, line a colander with 4 thicknesses of cheesecloth and set over a bowl.) The next day, measure the juice and add enough port wine to make 3 cups of liquid altogether. Combine the liquid and sugar in a large pot and bring to a full rolling boil over high heat. Add pectin and continue to boil hard, stirring constantly, for 1 minute. Skim the top and pour into hot, sterilized jelly glasses. Cover with a thin layer of melted paraffin. When the paraffin has hardened, cover the glasses and store.