Look what I made today:
3 1/2 cups sugar
3 tablespoons lemon juice
1 package of dry no-sugar pectin
Step 1 -Wash, cut, dice and Puree the watermelon!Place diced watermelon in a blender or food processor. You’ll need 2 cups of blended watermelon in total. Pour the 2 cups of blended watermelon into a large pot.Step 2 - Add lemon juiceAdd the 3 Tablespoons of lemon juice to the pot!
Step 3 - Mix the dry pectin with about 1/4 cup of sugar In a small bowl, mix the dry pectin with about ¼ cup of sugar. Keep this separate from the rest of the sugar.
Notes about pectin: I usually add about 20% more pectin or else the jam is runnier than I like.
Step 4 - Mix the watermelon juice with the pectin and cook to a full boilStir the pectin into the watermelon juice and put the mix in a big pot on the stove over medium to high heat (stir often enough to prevent burning). It should take about 5 to 10 minutes to get it to a full boil (the kind that cannot be stirred away).
Step 5 - Add the remaining sugar and bring to a boilWhen the berry-pectin mix has reached a full boil, add the rest of the sugar and then bring it back to a boil and boil hard for 1 minute.
Step 6 - Testing for "jell" (thickness)I keep a metal tablespoon sitting in a glass jar of water, then take a half spoonful of the mix and let it cool to room temperature on the spoon. If it thickens up to the consistency I like, then I know the jam is ready. If not, I mix in a little more pectin (about 1/4 to 1/2 of another package) and bring it to a boil again for 1 minute.
Step 7 - Fill the sterilized jars and put the lid and rings onFill them to within 1/4 inch of the top, wipe any spilled jam off the top, seat the lid and tighten the ring around them. Then put them into the boiling water canner!Step 8 - Process the jars in the boiling water bathKeep the jars covered with at least 1 inch of water. In general, boil them for 10 minutes.
Step 9 - Remove and cool the jars - Done!Lift the jars out of the water and let them cool without touching or bumping them in a draft-free place (usually takes overnight) you can then remove the rings if you like. Once the jars are cool, you can check that they are sealed verifying that the lid has been sucked down. Just press in the center, gently, with your finger. If it pops up and down (often making a popping sound), it is not sealed put the jar in the refrigerator right away. Once cooled, they're ready to store. I find they last up to 12 months. But after about 6 to 8 months, they get darker in color and start to get runny. They still are safe to eat, but the flavor and texture aren't as good.