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Low-Sugar Strawberry Jam {Canning Strawberry Jam}

Canning strawberry jam is so much easier than you think! Low-Sugar Strawberry Jam is a delicious and fresh tasting spread for yogurt, toast, or dessert recipes. Homemade strawberry jam is a treat for the whole family and is an amazing way to preserve the harvest. There is nothing like opening a jar of homemade strawberry preserves knowing YOU made it!

Three jars of homemade strawberry jam on a cutting board with strawberries and a spoon

The first time I tried canning traditional strawberry jam, it never thickened properly. And it was so sweet that it hurt my teeth. Thankfully, a few years ago, I was introduced to Pomona’s Pectin.

Making strawberry jam with Pomona’s was love at first bite. And now I get to make Low-Sugar Strawberry Jam exactly how I like it – not too sweet and tasting of summer.

Just a head’s up that this post is super long but don’t see that as “making and canning strawberry jam is hard”. This version of homemade strawberry jam is pretty straight forward and won’t make you throw a jam covered spoon across the kitchen like traditional strawberry jam recipes.

That um, happened to a friend of mine…

So, why is this post incredibly wordy? Because I have stuffed it full of information, tips, tricks, and hacks I have learned over 14 years of canning. I’m telling you EVERYTHING you need to know to be successful at making strawberry preserves in your very own kitchen.

You can always “jump to recipe” if you’d like, but I do recommend a read through at least once to make sure you understand what is going on.

And if you get to the end of this and realize canning is just not your jam (<—-see what I did there…?), I have a Strawberry Freezer Jam Recipe, No-Cook Raspberry Freezer Jam and Blackberry Freezer Jam recipes that you’ll love! No cooking, no canning; just fresh tasting freezer jam.

What Is Pomona’s Pectin?

Most commercial pectins are added to fruit along with bonkers amounts of sugar to create a “gel” that makes jam, well, jam. Most conventional recipes call for at least a 1:1 ratio of fruit to sugar. That means for a recipe that makes five jars of jam, you’re looking at needing 6-8 cups of sugar. SIX CUPS OF SUGAR PEOPLE.

Pomona’s, on the other hand, is activated by calcium (not sure) and needs just a touch of sugar to work. :confetti: This recipe makes five (8 oz) jars using just 1.5 cups of sugar.

Pomona’s is also gluten-free, vegan, certified kosher, and GMO free.

Can I Use Regular Pectin for Low Sugar Jam?

Such a bummer, but no. “Normal” jam recipes need all that sugar for the jam to set. If you go and mess with the measurements, your jam won’t set up properly. But hey, then you can make strawberry syrup I suppose or add it to Homemade Strawberry Ice Cream.

There are other low-sugar pectin brands that work well (Ball Low Sugar Pectin is great too!), but my heart belongs to Pomona’s because it has never once let me down.

This recipe has not been developed for using Stevia and any substitutions will likely result in a different texture. 

How to Use Pomona’s Universal Pectin

Pomona’s comes with two little packages; 1) calcium powder 2) and pectin.  

This is the calcium powder. You mix 1/2 tsp of it with 1/2 cup of water. You won’t use it all for this recipe; it’s gonna last you a long time!

Packets of Pomona's Pectin and calcium water on a grey cloth

Low-Sugar Strawberry Jam Ingredients

Homemade Strawberry Jam Equipment

  • Jars! Canning jars only (don’t use leftover mayo, jam, or pasta sauce jars from the store). I recommend 8 oz jam jars, or pints (16 oz for my American friends who like me, ignored learning this stuff in fourth grade) if your family goes through jam quickly.
  • Clean, never before used canning lids
  • Water bath canner or deep stockpot with a jar rack. 
  • Large saucepan. I adore my dutch oven for so many reasons, and jam season is another one of those reasons! Having a wide pot with high sides is best for making jam as it allows the jam to process at a rolling boil without slopping over the sides.
  • Ladle
  • Funnel
  • Jar lifter
  • Clean washcloths and towels
  • Medium mixing bowl
  • Knife and cutting board
  • Comfy shoes

Check out this Canning Supplies and Equipment List for a detailed explanation of all the supplies and brands I recommend.

Four jars of low-sugar strawberry preserves on a wooden board

Why Do I Have to Use Bottled Lemon Juice in Jam?

Fresh lemon juice is amazingly flavorful, but it’s not meant to be used in canning. The acidity of individual lemons can vary, but bottled lemon juice is consistent.

The natural pectin in the strawberries and the Pomona’s react to the citric acid in lemon juice and create an amazingly fresh tasting jam. The lemon flavor is not overwhelming in the jam, but it brightens the strawberry and improves the overall flavor without needing more sugar.

How to Make Low-Sugar Strawberry Jam

*A detailed and printable recipe is available at the bottom of this post

Canning Prep

Prepare your water bath canner by filling it with water, and setting it on the stove. Turn the burner to high. Once it reaches a boil, reduce it to simmer. You want to keep the water hot so that everything is ready when the jam is.

Wash and sanitize your jars. You’ll want to keep them warm to avoid having them crack when placed in the canner. You can fill them with hot water, or place them on a tray in the oven at 200 degrees F.

Wash your lids and set aside in clean place. You no longer need to simmer lids in water to keep them sterile. Woot!

Making the Strawberry Jam

Rinse the strawberries.

Remove the tops, and place in a heavy-bottomed saucepan. 

Heat the fruit over medium heat until the juices start to bubble. If your strawberries are ripe you should not need to add any water to the pot. Just stir often to prevent sticking, and soon the natural juices in the berries will be released. Be patient!

At this point, you can mash the fruit with a potato masher, but I prefer to be lazy and use my immersion blender. Pro tip: blend about 30% of the strawberries, and just gently pulse the others, leaving some chunks. The goal isn’t to puree the fruit totally as that will impact the final texture of the jam.

Two photos of strawberries in a pot being crushed for low sugar strawberry jam

In a small mason jar, combine 1/2 tsp calcium powder with 1/2 cup cool water.

In a separate bowl, combine sugar and pectin. Set aside. To prevent clumping in the fruit, Pomona’s must be mixed with your sweetener before being added to the fruit.

Add the lemon juice and calcium water to the pot with the strawberries, stir.  Add the sugar/pectin mixture, and bring to a rolling boil. Stir constantly for 3 minutes, turning down the burner to medium if the jam starts popping. Pro tip: actually set a timer and stir for the full three minutes. The constant stirring prevents the jam from burning, and the cook time is important to help the jam set.

Pro tip: a rolling boil means no amount of stirring will stop the bubbling. Use a long spoon or spatula to avoid any jam popping onto your hand. Dibs on “Jam Hand” as a band name.

At this point, turn the burner under the canner back up to high and get that water boiling again.

Remove the jam pot from heat, and stir gently for 5 more minutes. At the end of the 5 minutes, remove any foam that remains.

Three photos showing how to make low sugar strawberry jam

Using the funnel and a ladle, add the jam to your prepared jars, leaving 1/4 inch of headspace at the top. Headspace is the amount of room between the top of the food, and the rim of the jar.

Using a wet clean rag, wipe the rim to make sure there isn’t any sticky jam on there. 

Place a clean lid on the jar and then a canning ring. Tighten the ring to fingertip tight (tight enough that it won’t come off, but not so tight that a normal person couldn’t budge it).

Three photos showing how to fill and place the lids of jars of homemade strawberry jam

Using canning tongs, add your jars to the boiling water, and put the canner lid on. Pro tip: you must have at least 1 inch of water over the tops of the jars for safe canning. Process (boil) for 10 minutes. 

Remove the canner from heat, and let sit for 5 minutes. Remove the jars and place them on towels on the counter. Make sure you put them someplace where they can be undisturbed for 12-24 hours.

After everything has cooled, check the seal by pushing down on the middle of the lid. If it doesn’t give way, it’s sealed. Label the jars, and store in a cool dark place for up to a year.

If the lid bows a little bit, put that in the fridge and use it within 3 weeks.

Why Do You Have to Skim Foam From Jam?

Foam contains bubbles and bubbles is the enemy of safe canning. The volume of the foam can impact the amount of headspace in the jar which can increase the chance of spoilage.

Additionally, foam in jam just looks butt ugly.

Common Strawberry Jam Issues

Help, my jam didn’t set

I have found with Pomona’s that every batch has set because it doesn’t depend on the sugar to create the gel. If you’re using another pectin, the common reason for the jam not setting is that it wasn’t cooked long enough or the (appalling) amount of sugar called for was adjusted.

Jam must be fully cooled in the jars for 24 hours before it is determined if it has truly set. It thickens as it cools (TWSS?).

If your jam truly looks liquidy after 24 hours, Pomona’s has an amazing step by step guide on their site for troubleshooting and fixing jam issues.

How to test to see if jam is set – spoon/sheet test

If you want to double or triple check that your jam will set after canning, try the spoon/sheet test. Stir a metal spoon into the jam and hold it sideways above the pot. If the jam runs off in drips, then keep cooking it. It’s just not ready.

But, if the jam drops start to run together and come off the spoon in a sheet, your jam is done! Yay!

Help, the Bottom of My Jam Jar is All Juice!

Been there, jammed that.

Once your jam has set, there may be some settling happening in the jar. That’s normal! But sometimes, what the final product looks like is strawberry liquid on the bottom and actual jam on the top. Bummer.

This occurs when the strawberries were over crushed/smushed and too much juice was released. If you’re using a potato masher to process the strawberries, do so one layer at a time.

Can Strawberry Jam Be Doubled?

Yes, but jam is best in small batches. With that in mind, doubling the jam recipe is fine but tripling is not advised. 

You’ll want to double each of the ingredients, including the pectin.

Making Jam With Frozen Fruit

YES, you can use frozen fruit for making jam. Hurray! Check out this post on how to freeze strawberries if you have lots of leftover fresh berries.

How to Use Low-Sugar Strawberry Jam

You can use it for toast (check out Simple Whole Wheat Sandwich Bread), or as a topping for homemade Instant Pot Yogurt. I’ve even mixed it in with homemade cream cheese frosting to make strawberry cream cheese frosting. Which ruled.

How Long Does Canned Strawberry Jam Last?

You can keep an opened jar of low-sugar strawberry jam in the fridge for a month. Sealed jars are safely stored at room temperature for up to a year.

Three jars of homemade strawberry jam with fresh strawberries on a white board

Homemade Strawberry Jam Recipe Notes

  • The calcium water will last for three months in the fridge. Shake well before using it for other recipes.
  • You can reduce the sugar to 1 cup if desired but you would need to cook the jam down for 8 minutes instead of 3.
  • You can sub in honey if you’d like. Use 1 cup for this recipe. As the jam is cooked and then processed in the canner, any beneficial properties of using raw honey will be eliminated.

More Canning Recipes Like This

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5 from 5 votes
Low-Sugar Strawberry Jam {Canning Strawberry Jam}
Prep Time
20 mins
Cook Time
20 mins
Canning Time
10 mins
Total Time
50 mins
 

Canning strawberry jam is so much easier than you think! Low-Sugar Strawberry Jam is a delicious and fresh tasting spread for yogurt, toast, or dessert recipes. (Makes 5, 8 oz jars)

Course: DIY
Cuisine: American
Keyword: Easy Strawberry Jam
Servings: 64 servings
Calories: 24 kcal
Ingredients
Instructions
Prep for the canning part
  1. Prepare your water bath canner by filling it with water, and setting it on the stove. Turn the burner to high. Once it reaches a boil, reduce it to simmer. You want to keep the water hot so that everything is ready when the jam is.

  2. Wash and sanitize your jars. You'll want to keep them warm to avoid having them crack when placed in the canner. You can fill them with hot water, or place them on a tray in the oven at 200 degrees F.

  3. Wash your lids and set aside in clean place.

Jam
  1. Rinse the strawberries. Remove the tops and cut in halves or quarters (8 cups total). Place in a heavy-bottomed saucepan.

  2. Heat the fruit over medium heat until the juices start to bubble. At this point, you can mash the fruit with a potato masher, or use an immersion blender. Pro tip: blend about 30% of the strawberries, and just gently pulse the others, leaving some chunks. The goal isn't to puree the fruit totally as that will impact the final texture of the jam.

  3. In a small mason jar, combine 1/2 tsp calcium powder with 1/2 cup cool water.

  4. In a separate bowl, combine sugar (1.5 cups) and pectin (2.5 tsp). Set aside. To prevent clumping in the fruit, Pomona's must be mixed with your sweetener before being added to the fruit.

  5. Add the lemon juice (1/4 cup) and calcium water (2.5 tsp) to the pot with the strawberries, stir.  Add the sugar/pectin mixture, and bring to a rolling boil. Stir constantly for 3 minutes, turning down the burner to medium if the jam starts popping. Pro tip: actually set a timer and stir for the full three minutes. The constant stirring prevents the jam from burning, and the cook time is important to help the jam set.

  6. At this point, turn the burner under the canner back up to high and get that water boiling again.

  7. Remove the jam pot from heat, and stir gently for 5 more minutes. At the end of the 5 minutes, remove any foam that remains.

  8. Using the funnel and a ladle, add the jam to your prepared jars, leaving 1/4 inch of headspace at the top. Headspace is the amount of room between the top of the food, and the rim of the jar.

  9. Using a wet clean rag, wipe the rim to make sure there isn't any sticky jam on there. Place a clean lid on the jar and then a ring. Tighten the ring to fingertip tight (tight enough that it won’t come off, but not so tight that a normal person couldn’t budge it).

  10. Using canning tongs, add your jars to the boiling water, and put the canner lid on. Pro tip: you must have at least 1 inch of water over the tops of the jars for safe canning. Process (boil) for 10 minutes. 

  11. Remove the canner from heat, and let sit for 5 minutes. Remove the jars and place them on towels on the counter. Make sure you place them someplace where they can be undisturbed for 12-24 hours.

  12. After everything has cooled, check the seal by pushing down on the middle of the lid. If it doesn't give way, it's sealed. If the lid bows a little bit, put that in the fridge and use it within 3 weeks.

  13. Label the sealed jars, and store in a cool dark place for up to a year.

Recipe Notes

Makes 5, 8 oz jars.

8 cups fresh strawberries generally equal about 5 cups of mashed berries.

Will last for 1 month in the fridge or 12 months sealed and at room temperature.

Nutrition Facts
Low-Sugar Strawberry Jam {Canning Strawberry Jam}
Amount Per Serving
Calories 24 Calories from Fat 9
% Daily Value*
Fat 1g2%
Saturated Fat 1g6%
Sodium 1mg0%
Potassium 29mg1%
Carbohydrates 6g2%
Fiber 1g4%
Sugar 6g7%
Protein 1g2%
Vitamin A 5IU0%
Vitamin C 11mg13%
Calcium 3mg0%
Iron 0.1mg1%
* Percent Daily Values are based on a 2000 calorie diet.

As an Amazon Associate, I earn from qualifying purchases.

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32 comments on “Low-Sugar Strawberry Jam {Canning Strawberry Jam}”

  1. Could you freeze instead of canning?

  2. loved making this!

  3. This looks nice and easy! Thanks for sharing!

  4. I love Pomonas! I’ve tried other jam making products, but this is clearly my favorite. The flavor is amazing and I love that it’s low sugar. I’ve been using it for years.

    I’m hoping to pick raspberries this weekend and make some jam (using Pomonas, of course)!

  5. How funny. I just bought a brand new canning utensils set at Goodwill for $2.99. It looks like now I have a recipe to try!

  6. I went out and bought some to make strawberry jam which I haven’t done in a few years because of all the sugar. Thanks so much.

  7. Thanks! This makes me want to can, but I’ve downsized and where would I put all that stuff (the pots and all; I don’t even own (shocking!) a crockpot!) Sounds to me like Pomona’s is the way to go, so my jam lovin’ husband can mean it when he eats jam and declares he’s had “a serving of fruit!”

    Jam on! I had a friend I walked with every day when the kids were young. I called her Jane, but when the kids were around, I’d then look at them and say, “Mrs. Taylor to you,” so they’d call her Mrs. Taylor. One day my youngest asked, “Are you going with Mrs. Taylortoyou?” Sheesh.

  8. THANK YOU! I always wondered how the commercial jams made the “sugar-free” or 99% fruit versions! I love making jam, but like most of the other posts, gasp at the amount of sugar… I wonder if I can get the calcium powder in Australia? Otherwise, I’ll just import it! And I love your little jars… their so cute!

  9. Very nice post and pics. I have canning jars, and every time I get berries we eat them. I really need to do this ! 🙂

  10. Thanks for posting! I switched to pomona’s last year. I was planning to go strawberry picking with the girls this week…but…it has been raining for days! I am afraid to think what the fields look like! And there is rain in the forecast for several days! What am I going to do? I need my 50 pounds of strawberries!! I will probably just go on my own this weekend and brave the weather an mud. I will post my recipes on my blog next week. Come on New York-stop raining already!

  11. This is absolutely fantastic! I live in Amish country, and they’re basically the queens of freezer jam, which is yummy, but so sweet it sends electric shocks through my fillings when I bite into my toast. I’ve never even had the slightest desire to make jam before, but now I do. Next year, we are planning on adding a giant strawberry box to our square foot garden, and this recipe will be on my list of “yummy things with which to fill my freezer.” How do you find the taste? Is it jarringly (haha, see what I did there) different than the regular jam, sweetness-wise?

  12. Can’t wait to try this tomorrow. Do you have a place to subscribe to your emails or to follow you on FB and or Twitter? I’d love to follow you! 🙂

    • Hi Leila, under the Google Followers over on the right side of my page, there is a box where you can enter your email address and subscribe to the RSS feed. I’m not on Twitter, but I am on Facebook. On the right of the page above the Google Followers is a little Facebook badge. Click on that and it will take you to my page to like it.

  13. This sounds great. I too hate all that sugar!

  14. Lookin’ good!

  15. The first time I made jam I used Pomona’s. When I tried something else, I was shocked by how much sugar it called for! I will certainly be using Pomona’s again. Thanks for reminding me that I can use strawberries now since they’re in season!

  16. Okay I think I am ready. Last Christmas all I asked for was canning stuff! For the pictures in this post, how many pounds of strawberry’s did you start with and how many cans of “jam on” did you end up with?
    Thanks Sarah you are awesome! I am in Vancouver WA and have been (stalking) following your blog now for 2 years, and I think I am finally ready to try canning…
    Thanks!

    • What GREAT Christmas presents!!! I just had to go back and do some math for you to figure out the yield.

      We had about 32 lbs of strawberries. That made 38 jars of jam that were canned, and 3 more that weren’t full enough to be canned, so were just put in the fridge directly.

      In addition to that, we froze about 2.5 gallons of whole strawberries, and Jack also ate his weight in fresh berries. ;-D

    • Thank you so very much!

  17. Beautiful! Awesome! Beautifully awesome?!?! Maybe this is the year I actually try this. Thanks so much for the step-by-step tutorial. Really looks fabulous! Pinning.

    Christine 🙂

  18. Jam on, girlfriend.

  19. This looks awesome! I’ve been wanting to make my own jam, but didn’t want to deal with all the sugar.

  20. Okay, I don’t care if you’re not an “expert”, I am so going to do this! Last summer was my first time canning, and all I did was pickles and jalapenos. I really like the tips about keeping the sanitized jars and lids clean. Very helpful.

    • You have it correct – start with easy pickled items, and then move in to something that requires a bit more work. I started with jam, and it actually turned me off of canning for a bit.

      I hope you enjoy making this!