Watermelon Jelly

4 cups watermelon, remove seeds (not rind)
3 1/2 cups granulated sugar
2 tablespoons lemon juice
1 (6 ounce) bottle liquid fruit pectin

Place watermelon in blender or food processor and blend or process until smooth. You should end up with 2 cups purée.

In large cooking pot combine watermelon purée, sugar and lemon juice. Bring mixture to a full rolling boil. Add pectin all at once. Boil hard for 1 minute, stirring constantly. Remove from heat; skim off foam.

Ladle jelly into clean hot half-pint jars; seal. Process in a boiling water bath for 5 minutes.