Clean and clear up your workspace because this recipe is messy and gets all over everything (if you cut a watermelon like I do).
Find a ripe large watermelon. Wash the outside with cold water. Use a melon ball scoop to scoop roughly 7 cups of watermelon into a food processor or blender.
Puree the watermelon so you have approximately 6 cups.
Combine the pureed watermelon into a large pot (I use Cuisinart 5.5 Multi-Purpose Pan with glass cover) with the 1/2 cup lemon juice and 4 cups white sugar or sugar substitute.
Bring combination to a boil until the temperature of mixture reaches 220 degrees.
Add the powdered pectin and boil for another 5 minutes.
Remove from the heat and pour into sterilized jars.
*I used 12 4oz Jelly Jars. These can be found at your local grocery store or wherever you can purchase canning supplies.
Throughly wipe the rims and apply lids and screw on bands. *This is a very important step... without doing this the vacuum seal may not set properly.
Process in a boiling water bath for 15 minutes.
Remove from water bath and allow to cool in an area that is dark and away from drafts.
*I leave mine sit overnight and test the seals in the morning. That way I am positive that the seal has set properly.
If the seals have set properly on your jars... you can eat immediately or store unopened jars for up to a year!