PLUM JELLY

5 lb. plums 7 1/2 c. sugar 1 box Sure-Jell (fruit pectin) 1 1/2 c. water Pit, do not peel, plums. Finely chop or grind fruit. Place in large saucepan, add 1 1/2 cups water. Bring to a boil. Cover and simmer 10 minutes, stirring occasionally. To extract juice, place prepared fruit in a dampened jelly bag or several thicknesses of cheese cloth. Allow ample time for juice to drip through. When dripping is almost ceased, or to speed up the extraction, gently press or squeeze bag.Use 5 1/2 cups of juice, place juice in large saucepan. Stir in fruit pectin, bring to a full rolling boil, immediately stir in sugar, bring to a full rolling boil stirring continuously. Boil for 1 minute. Remove from heat. Skim off foam, place in prepared jelly jars. Preparation of jelly jars: Place jars in boiler or cooking utensil sufficiently deep to allow water to flow over top of jars, bring to a boil. Fill with jelly while still hot, wipe rim with a damp cloth to remove any jelly. Place lids, that have been heated in hot water, on jars, tighten rings over lids, return to boiler and boil for 5 minutes at slow boil. Remove from water and allow to cool.