Watermelon Jam. Saving Summer for Later.

I love watermelon, but you can’t grow it in the dead of winter. But I can surely grow them in the summer–10 to 15  large watermelons.  By the third watermelon, my children scream”ENOUGH.”  So, what happens to all those watermelons?  I either give some away and the rest, I juice and store in the freezer to make watermelon jam in the winter.

But that’s not all.

I come from the waste not background, and try to use every part of the plant.  So, I also cut off the watermelon rind and save the peels as well for later use.  (Stay tune for another post.)

Back to watermelon jam.

Canning Watermelon

The juice of watermelon makes an excellent jam and one of my children’s teachers’ favorite.  There are several recipes on the internet, but I felt most comfortable using a recipe from Ball Complete Book of Home Preserving since they test their recipes for food safety. (The recipes in this book are wonderful and like I said before, they have been tested for safety.  You have to be very careful when using canning recipes on the internet.)

Why am I worried about canning safety?

Only fruits with a pH of 4.6 or lower can be canned safely in a water bath canner; otherwise, you could contract botulism due to improperly canned food. It can be fatal.

According to Wisconsin Extension:

“The pH of 4.6 is important in determining whether the Clostridium botulinum bacteria will grow in canned food and produce a deadly neurotoxin. At pH 4.6 or below (high acid foods), Clostridium botulinum will not grow and produce the deadly toxin, so these foods can be given a relatively mild canning treatment using a boiling water canner. At pH above 4.6, Clostridium botulinum is able to grow and produce toxin unless the food is heated to high temperatures in a pressure canner. Foods that are naturally high in acid like oranges, apples and most fruits can be safely canned in a boiling water canner. Foods that are low in acid like meats and vegetables; must be pressure canned.”

Watermelon is a low acidic fruit so you must add lemon or vinegar to the jam.

In Ball’s recipe, they add both apple cider vinegar and lemon juice.  However, in most recipes I saw on the internet, a generous amount of lemon juice was added to the recipe.

Watermelon Jam Recipe

I adapted this recipe from Ball’s recipe:

6 cups Watermelon puree.

5 cups of organic sugar

4 Tablespoons of organic lemon juice (If you use fresh lemon juice, keep the rinds in the freezer for lemon zest.)

1/2 cup of organic apple cider vinegar  (You can make it HERE or buy it HERE.)

2 Tablespoons of dried, crushed lemon verbena (optional)  (Switch it up and use mint too.)

6 teaspoons of powdered low sugar pectin or 2 boxes.  (Very important)

1.  Puree the watermelon in a juicer.  Using a juicer is much quicker than removing the seeds by hand and letting the watermelon drip to create a puree.

2.  Start boiling your water in your canner since it doesn’t take that long to make this jam.  You want to have at least 2 inches of water above the jars you are using.  I use pints for this recipes.

In addition,  I use my pressure canner as a water bath canner.  Most use a water bath canner.  You can buy one HERE.   You can also  sterilize your jar in the canner while the water boils.   I don’t since I put my jars in the oven at 200 degrees.

Word to the wise: Be sure to purchase a rack.  Lifting those jars in and out of boiling water isn’t fun.

Ask Hubs.  He will tell you it is absolutely no fun.

3.  Also prepare your lids, jars, and rings.  I put my lids and rings in a sauce pan in hot water.

4.  Add a few small plates or spoons to your freeze.  You will use them to test if your jam has jelled.

5.  Add the watermelon puree, sugar, lemon juice and apple cider vinegar to the pot.   Bring to a roaring boil.  (A roaring boil is one that you can’t stop when you stir the liquid.)

You want to use a large tall pot so the jam can foam up.  I  used two different pots since I had 18 cups of watermelon to process.  My favorite was a stainless steel 18 quart pot.

FYI–Don’t. I repeat. Don’t try to prepare two batches at once.  One will get ruined.  Thank goodness I figured this out quickly and stopped working on the second batch.

6.  Add the pectin at this point, and boil for another minute.

7.  Get out a cold plate and pour a small amount of jam on the plate.  Wait a minute and then run your finger through the jam.  If it stays separated, it is ready.  If it runs back together, keep stirring and try again in another minute.

8.  Once the jam is ready, move quickly.  Turn off the fire.  Get your canning supplies ready and one by one fill your jars with jam leaving a 1/4 inch space at the top.

9.  Be sure to keep your rims of your jars clean so that the lids can properly adhere to the jars.

10.  As you finish your jars, put them one by one in the water bath.

11.  Process for 10 minutes after the water starts to boil.  (Put your lid back on your water canner so that it boils.  Since I use my pressure canner, I use the lid of one of my large pots.  It is just easier to use.)

12. Turn off the flame under the water bath canner, and let the jars sit for 5 minutes.  Then,  pull them out of the canner and let them rest for 24 hours. Don’t worry about water on top of the lids.  The water will eventually evaporate.  Some people put a towel over them to keep any drafts from disturbing the jars.

After 24 hours, check to make sure the lids have sealed.  If you can press the lids and they make a noise then, the jar did not seal.  Put that jar in the refrigerator.

Notes:

1.  Immediately soak your jam pot.  The remaining jam hardens and it isn’t fun to clean up.

2.  Be sure to use two packages of pectin.  It won’t set otherwise in my opinion.

Watermelon Jam Results:

I had a jar that I store in the refrigerator for tastings.   Each one of my guinea pigs friends took a spoon and tried the jam.  Some said it tasted like honey while others said they could taste the watermelon. I was a little disappointed that they couldn’t taste the watermelon.  They all gave the jam thumbs up.

PS I could taste the watermelon and think it is DELICIOUS!

Join the Conversation:

Would you make watermelon jam?

Do you like making fruit jams?

Disclaimer:  There are affiliate links in this post.  Any monies made helps support Green Talk.  Thanks for your loyalty.

Similar Posts:

• Canning Tomatoes Recipe–A Better Way.
• Apple Core Apple Juice Recipe. Use those Cores!
• Crockpot No Sugar Applesauce: No Additives. Just Good Tasting
• Food Preservation During a Power Loss. Canning in the Dark After Sandy
• 12 Canning Tips I Wish Someone Taught Me.