The fruity taste of strawberries really shines in this low-sugar strawberry freezer jam made easy in the microwave. Plus tips + tricks for setting jam!

Low-Sugar Strawberry Freezer Jam

One of the supermarkets in my area had a ridiculously good deal on strawberries. $3.99 per flat! For those who don’t know, a flat is 8 pounds of strawberries! I needed some fruit for a party I was having, but there was plenty to spare, so I decided to make some freezer jam.


I searched for a good recipe, and found some I liked, but was shocked about the amount of sugar in almost every recipe I found. I wanted a low-sugar strawberry freezer jam, so I decided to try and make it with less sugar.

At first, it was unsuccessful, which I am sure had nothing to do with the sugar and I will tell you why in a minute.

I ended up with jam that separated as soon as I poured it into my jars: fruit on top and liquid on bottom. I knew it wasn’t going to set, so I added more Pectin and re-heated my mixture, and it worked great.

Low-Sugar Strawberry Freezer Jam


Sugar draws liquid from fruits, which is also known as maceration.

When my low-sugar strawberry freezer jam was still runny after my first attempt, the fact that I used less sugar had nothing to do with it. After all, I had used less sugar, so hypothetically, there wouldn’t have been as much liquid drawn from the fruit, right?

Maybe or maybe not, but none of that mattered anyway because the sugar is not going to make a jam more thick or less thin; it’s not a thickening agent. The Pectin is the key thickener in jams.

Fruits naturally have Pectin, but the riper the fruit, the less Pectin the fruit naturally has. Strawberries are already lower on the Pectin spectrum.

Heat makes Pectin form into a gel. So when I added more Pectin and re-heated my mixture, the heat helped the Pectin gel up and it worked beautifully.

Low-Sugar Strawberry Freezer Jam


I am pretty confident in saying, if you have runny jam, extra Pectin (start with 1 Tbsp more) AND Heat will fix your problem.

Here is some Pectin, fruit, and jam science facts for you:

“When dissolved and let cool, Pectin forms invisible strands that hold liquid in. Acid (such as lemon juice) helps draw even more Pectin out of fruit when it is heated. Water is attracted to sugar. Adding sugar causes some water to be drawn to the sugar molecules, leaving the Pectin molecules free to more easily get at and bind with each other, setting the preserve.” (Source:

So now that you know why you might be having problems with strawberry jam setting, you can go ahead & try this recipe! I hope it brings you success!

Low-Sugar Strawberry Freezer Jam


Yes! Just keep in mind the natural pectin in the fruit you are using and adjust the pectin as needed. Check out this pectin chart to help you. We’ve tried this recipe with strawberries and peaches.


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  • Cheesecake Stuffed Strawberries – A super easy to make, no-bake dessert that is light, fruity and delicious. Low carb and keto friendly.
Low-Sugar Strawberry Freezer Jam

Low-Sugar Strawberry Freezer Jam

Prep Time: 10 minutes
Cook Time: 10 minutes
Inactive Time: 20 minutes
Total Time: 40 minutes
Yield: 5 - 6 half pints (8oz jars)

The fruity taste of strawberries really shines in this low-sugar strawberry freezer jam made easy in the microwave.


  • 3 1/3 cups crushed strawberries (about 2lbs strawberries)
  • 2 Tbsp lemon juice
  • 6 Tbsp Ball Classic Pectin OR 3 Tbsp Low or No Sugar Needed Pectin (equivalent to about 1 box of other brand pectin)
  • 1 1/2 cups granulated sugar


  1. Wash, hull and crush strawberries in a LARGE (10 to 14-cup) microwaveable bowl to equal 3⅓ cups. You may use a potato masher, food chopper, or food processor to crush the strawberries; do not puree--leave slightly chunky. Add lemon juice and Pectin. Mix well. Let it sit at room temperature for 20 minutes.
  2. Add sugar; stir until mostly dissolved. Heat in the microwave on high for 10 minutes until boiling and foamy. (Keep an eye on it so it doesn't boil over.) Remove and stir one last time. Mixture will still be thin.
  3. Skim the foam off the top, then pour jam into clean freezer containers leaving ½-inch head space for expansion. Your jam should look consistently chunky throughout the jar after it is poured into the jars. If the fruit has risen to the top and the liquid remains at the bottom, pour the fruit back into the bowl, add one additional tablespoon of Pectin and heat again until boiling and foamy.
  4. Immediately top with lids and let stand at room temperature for 1 to 2 hours to cool down before placing in the freezer. Refrigerate up to 3 weeks or freeze up to 1 year.
  5. *To use freezer jam: Pull from the freezer, allow to thaw in the fridge, and use like store-bought jam. (The freezer is for storing purposes, since the jam was not canned in a hot water bath.)

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