Red Plum Jelly
4,6 / 10
ready in 51 min.
Wash the mason jars, rings and lids in hot soapy water; rinse in warm water. Sterilize all pieces in boiling in boiling water. Drain well before filling. Fill a water-bath canner half-full with water and bring to a simmer.
Meanwhile, place chopped plums in a large saucepan and add 1/2 cup water. Bring to a boil, reduce heat, cover and simmer for 5 minutes. Measure exactly 6 cups prepared fruit into an 8-quart saucepan. Stir pectin into the fruit mixture and add butter to reduce foaming. Bring mixture to a full rolling boil over high heat, stirring constantly. Stir in sugar and return to a full boil and boil for exactly 1 minute, stirring continuously. Remove pot from heat source and skim off any foam using a metal spoon.
Immediately ladle jam into prepared jars, filling to within 1/4-inch of tops. Using a clean kitchen towel or paper towels, wipe jam from jar rims and threads. Cover with lids and bands. Screw bands on tightly. Place jars on rack in canner. Lower rack into canner, water must cover jars by 1 to 2-inches. Cover, bring water to a gently boil and process for 10 minutes. Remove jars and place upright on a clean kitchen towel to cool. Once jars are completely cool, check seals by pressing the center of each lid. If the lid springs back, the lid did not seal properly and the jar should be refrigerated.