Low Sugar Strawberry Freezer Jam + Video
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!
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.
Low-Sugar Strawberry 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.
Save This recipe
Enter your email below to get a link to this recipe emailed straight to you to save later! Plus be signed up for all new recipes.
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.
The Science of Sugar and Pectin in 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.
Tips and Tricks to Setting 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: http://www.cooksinfo.com/pectin)
So now that you know why you might be having problems with strawberry jam setting, you can go ahead and try this recipe! I hope it brings you success!
Ingredients for Low-Sugar Strawberry Freezer Jam
For this low-sugar strawberry freezer jam recipe you need four ingredients.
- Fresh Strawberries
- Lemon Juice
- Low/No Sugar Pectin
- Granulated Sugar
How to Make Strawberry Freezer Jam
To make the strawberry freezer jam, you will:
- Crush the strawberries by pulsing them in a food processor or blender. Do not purée completely.
- Stir in the lemon juice and pectin. Let sit at room temperature for 20 minutes.
- Add the sugar and stir until mostly dissolved.
- Heat in microwave on high for 10 minutes until boiling and foamy.
How to Tell if Your Freezer Jam will Set
Once the jam has boiled sufficiently, the best way to tell if it will set is looking at the mixture from the side.
It’s best if you use a clear bowl to cook it in. You can also look through the container you will be storing the jam in, as long as it is clear.
If the mixture has a consistent texture of fruit and liquid throughout, it should set properly.
If the mixture separates into liquid on bottom and fruit on top, you will need to add additional pectin (1 Tablespoon) and bring the mixture back to a boil. Then check it again.
Filling the Jars
- Once the jam mixture looks consistent, skim the foam off the top and discard it.
- Use a ladle and funnel to fill jars, leaving 1/2-inch head space for expansion.
- Immediately top with lids and let stand at room temperature for 1 to 2 hours to cool down before placing in the freezer.
Will this Recipe Work with Other Fruits?
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.
How to Store Freezer Jam
You can store this un-processed strawberry freezer jam in the fridge up to 3 weeks or in the freezer up to 1 year.
It’s best to use a freezer-safe container. Here are some options:
- Glass Mason Jars – are freezer safe as-is. I prefer to use the 8 oz jars, or half-pint size. The mini 4 oz jars are so cute and great for gifting. Stick with brand names here, Ball or Kerr have been around for years and make quality products.
- Plastic Lids – You can use the lids and bands that typically come with the glass mason jars, but since you are not canning this strawberry freezer jam, I prefer to use these screw on plastic lids that come in regular or wide mouth.
- Plastic Jars – If freezing glass makes you nervous, try these Ball Plastic Freezer Jars or these Screw Lid Freezer Containers.
NOTE: Be sure to add the date to the jar so you know when you made it. ( I write the date with a sharpie onto some masking tape attached to the lid.)
More Strawberry Recipes
Looking for more ways to use a lot of strawberries? Try these strawberry recipes:
- Strawberry Crisp
- Strawberry Cream Pie
- Cheesecake Stuffed Strawberries
- Strawberry Bars
- Strawberry Delight
Low-Sugar Strawberry Freezer Jam
Ingredients
- 4 cups (.91 kg) crushed strawberries, (about 2 lbs strawberries)
- 2 Tablespoons lemon juice
- 3 to 4 Tablespoons Ball Low or No Sugar Needed Pectin, (equivalent to about 1 box Sure-Jell Less or No Sugar Needed Pectin)
- 1 ½ cups (300 g) granulated sugar
Equipment
Instructions
- Wash, hull and crush strawberries in a LARGE (10 to 14-cup) microwaveable bowl to equal 4 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.
- 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.
- 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.
- Immediately top with lids and let stand at room temperature for 1 to 2 hours to cool down before placing in the freezer.
Video
Notes
- If you can't find low/no sugar pectin, you may substitute 6-8 Tbsp Ball Classic Pectin.
- To store the jam: Refrigerate up to 3 weeks or freeze up to 1 year.
- 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.)
Nutrition
Did you make this?
Don’t forget to leave a rating below and make sure to follow on Pinterest and Instagram for more!
*Originally published 5/7/13. Photos updated March 2022.
I just made this tonight and I was quite surprised as I only got 3, 8 oz jars after skimming the foam… Did I do something wrong? It certainly was easy to make!
Hmm. That’s a bummer. Maybe your was just extra foamy.
Thanks for such a detailed and well-written recipe! I was forced to buy low sugar pectin because the store didn’t have the regular, and it was hard to find a recipe that listed specific amounts to help me use it for freezer jam (first timer here, so not a lot of confidence in improvising). Tried it this morning and it was great!
Glad I could help! So happy you enjoyed this recipe!
It’s been a long time since I have made this recipe….I used 8 oz jars and I think it made somewhere between 6 and 10 jars. I now use Ball RealFruit Instant pectin. It uses about the same ratio of sugar to berries. It only takes 30 minutes and noooo cooking!
Wow! Will have to try that instant pectin! Thanks Linda!
Hi! I’m making this today but need to make sure I have enough jars 😉 do you happen to know how many jars/containers it made for you? And their sizes? Thank you!!!!
Hey Morgan,
I tried leaving a comment yesterday from my phone, but I see that it didn’t work. Hopefully you had what you needed. It made 5-6 (8oz) jars for me. I’ll add that to the recipe card.
A few years ago there was a recipe for low sugar. It only used 2 cups of sugar. It always turned out fine. About two years ago they changed the recipe. It did not turn out the same. It set but it separated. This year the recipe is not on the sheet. They only have the box with the artifical sweetner now. Does anybody remember this? I wonder why they stopped the recipe,because it always worked good. This was on the Pecton box. Doesn’t cooking the strawberries change the color of them to a darker color?
It’s always upsetting when they change the directions on the box. My recipe has worked well for many people. Cooking the strawberries doesn’t darken them very much, as you can see the final product in the pictures of this post. I hope you’ll give my recipe a try.
I love your recipe , I have made peach too , on the stove top and it is great , I would like to try pineapple with a hot pepper minced in with it , is pineapple a high pectin fruit ? Do you have a recipe for something like that , I love the low sugar in the recipes
Hi Sandy, I bet this would work for pineapple too. It’s low in pectin like strawberries, so I’m betting you won’t have to adjust anything. Good luck!
Ok – I made the regular freezer jam last night ( I did question the amount of sugar in my mind) and checked it today to see how it set up. It set up ok but oh my aching sweet tooth – TOO sweet! Plus the sugar didn’t dissolve all the way. Is there any way to salvage this? I have more berries – my thought was to get some of the low sugar pectin add some more lemon juice and put the whole mess in a pan on the stove. Can the 2 different pectins be used together (the one I used was liquid for freezer jam – Certo)? Or maybe just make a new batch with the berries left. 22 pint jars of jam is a lot to throw away.
If the sugar didn’t dissolve you definitely need to cook it longer. It needs to boil and dissolve completely, but don’t overcook it either. If you are doing a big batch, make sure to use several pots so it heats evenly. You can add more fresh berries to try and thin out the sweetness and definitely try more pectin and a little more lemon juice. I’m not sure about mixing the two pectins together though. Good luck! Here’s a great article that may help you: http://www.pickyourown.org/pectin.htm
Wow! Thanks for the fast reply, truly appreciated! The pectin I used didn’t call for heating on the stove, just mix for 3 mins with the lemon juice. I did check a couple of other jars and the sugar doesn’t seem to be a problem ( the one I tasted was from the jar of a little left over from batch to batch) but the sweetness – UGH. It’s been about 8 years since the last time I made any and I don’t remember it being this sweet, nor my Gma’s (40 yrs ago). I’m going to go with your suggestion of more berries, pectin and lemon – that makes sense to me. Again thanks for the quick reply – you have probably saved 22 jars – I think I hear some clapping from the kitchen.
This is the BEST strawberry freezer jam I have ever tasted! Better than high-sugar. Do you have a recipe for low-sugar raspberry jam or can substitute the raspberries straight across?
Hi Jackie! So glad you like this recipe! You can absolutely swap fruits. Just keep in mind the natural pectin of the fruit and adjust the additional pectin as needed. Raspberries should work just like the strawberries with no additional adjustments. Enjoy!
I haven’t read through all the comments but would your low sugar method work with other fruits? Raspberries, blueberries, haskaps, wild low and high bush cranberries and blackberries?
In most cases, yes. The sugar doesn’t effect the ability to make jam set, it just makes it sweeter. The natural pectin found in a particular type of fruit might effect the jams texture though. Some fruits have less pectin than others, so you may have to adjust the quantity of the pectin you add to it. Just google “fruit pectin chart” and you should be able to find good info on how much pectin fruits naturally have in them to give you an idea on how much additional pectin to add.
This looks really good, and judging by all the comments, is good! I have been looking at freezer jam but was worried about the sheer quantity of sugar required.
I would love to have a go but here in the UK we use different measures: weight not volume. Have you any idea how I can convert this to lbs and oz?
I am dying to try it and am going out right now to buy some pectin. Not sure about the different brands, but I’m assuming they will be roughly equivalent?
Hi Jenni,
Try this, I hope I converted everything right:
2 pounds of strawberries.
2 Tbsp lemon juice is 1 ounce.
6 Tbsp of pectin is about 1.75 ounces.
1 1/2 cups sugar is about 10.65 ounces.
Good luck!