Makes about 2 pints
2 ½ cups cubed watermelon
2 tablespoons fresh lime juice
1 ½ cups sugar
½ cup honey
1.75 oz package of pectin
Place cubed watermelon in a blender and blend on high until smooth. Strain watermelon mixture through a fine mesh sieve until all of the juice is separated from the pulp. Reserve 2 cups juice.
Bring watermelon juice to a boil over medium high heat in a saucepan. Once boiling, add lime juice, sugar and honey. Bring mixture to a full rolling boil over high heat, stirring constantly.
While waiting for the juice to come to a boil, take 1 cup of water and microwave for 2 minutes, until boiling. Add the package of pectin to the hot water and stir until completely dissolved.
When the fruit mixture is boiling, quickly stir in the pectin mixture. Return to a full rolling boil and cook for another minute, stirring constantly. Remove from heat. Skim off any foam with a metal spoon.
Ladle hot jam into jars, leaving 1/4-inch of headspace. Wipe the rims clean and top with lid; screw on ring until finger tight. Process in a boiling water bath for 7 minutes. Remove from water and let cool completely, 12 to 24 hours. Check seals. Any unsealed jars should be refrigerated and used within 1 month.