Wash apples; remove blossom ends and stems. Do not peel or core. Cut apples into small chunks. In 8 to 10 quart kettle, combine apples and enough water to cover apples, about 5 cups. Cover and bring to boil over high heat. Reduce heat; simmer until apples are soft, 20 to 25 minutes.
Strain cooked apples and liquid through jelly bag; measure 4 cups juice. In 8 to 10 quart kettle, stir together apple juice and sugar until dissolved. Bring mixture to full boil. Boil hard, uncovered, until syrup sheets off a metal spoon, 10 to 12 minutes.
Remove from heat; quickly skim off foam with metal spoon. Pour into sterilized jars; seal. Makes 3 half-pints. Serves 3.