- Whisk together sugar and powdered pectin until they are fully combined. In a large pot, combine watermelon puree, sugar mixture, lemon juice and zest. Bring to a boil and cook until the jelly reaches 225°F.
- Remove from heat and pour into prepared jars. Clean the rims, place the lids and screw on the bands. Process jars in boiling water or a canner for 10 minutes.
- After 10 minutes, remove from canner and allow jars to cool. Jelly may not be set for up to one week, but you can eat immediately, if desired. Store unopened jars in a cool, dark place for up to one year.
Recipe developed for Imperial Sugar by Susan Whetzel @doughmesstic.