Strain through 2 thickenesses of cheesecloth. The juice is ready. Place juice in a large pot. Mix pectin with juices and bring quickly to a hard boil, stirring occasionally. Add the sugar at once. Stir sugar until it dissolves and bring to full rolling boil (a boil that can not be stirred down). Boil hard for 1 minute, stirring constantly. Remove from heat; skim off foam using a metal spoon. Pour at once in sterilized jars, leaving 1/4 inch headspace.