How to Make Low-Sugar Strawberry Jam

Last week we ended up with way too many strawberries. My 18-year-old daughter Abby did the grocery shopping while I was out of town and came home with more fruit than we could eat. It turned out to be a happy problem: I finally had an excuse to make my favorite low-sugar strawberry jam. Homemade jam preserves the bright flavor of fresh berries and is surprisingly simple to prepare.

Making jam at home is straightforward, and once you’ve tried it you’ll likely prefer it to store-bought preserves. This low-sugar strawberry jam recipe uses fresh fruit, low-sugar pectin, lemon juice and a moderate amount of sugar to create a flavorful, spreadable jam. Below are the tools, ingredients and step-by-step instructions to help you make a reliable batch.

Essential canning equipment

• Water bath canner with a rack
• Half-pint (8 oz) Mason jars with lids and rings
• Jar lifting tongs
• Canning funnel
• Optional: magnetic lid lifter

Most of these items are one-time purchases and will last for years; only the jar lids and rings need routine replacement. If you don’t own canning equipment yet, consider assembling a basic canning kit so you can preserve fruits and sauces safely.

Kitchen tools you will use

• Colander
• Potato masher
• Large, wide pot for boiling the jam
• Wooden spoon or heat-proof silicone spatula for stirring
• Large spoon for skimming foam
• Large liquid measuring cup
• Dry measuring cups and spoons
• Ladle
• Small ceramic plates (for testing jam set)
• Clean kitchen towels

Start by inspecting 6–7 half-pint Mason jars. Run your finger around each rim to make sure it isn’t chipped—chipped jars won’t seal properly. Wash the jars in the dishwasher or by hand with hot, soapy water and set them aside to dry on a clean towel or rack. Put two small ceramic plates in the refrigerator so you can test the jam’s set later.

Wash and hull about 8 cups of fresh strawberries. Eight cups of whole berries should yield roughly 5 cups of mashed strawberries, which is the amount used in this recipe. The quality of the fruit affects the final flavor, so choose ripe, fragrant berries when possible. Cut the strawberries in half and mash them in a large bowl with a potato masher. Mash to your preferred texture—this recipe produces a nicely spreadable jam with small fruit pieces if you don’t over-mash.

A key ingredient in reduced-sugar preserves is low-sugar pectin. This product is formulated to work with less sugar and includes a mold inhibitor needed for reduced-sugar recipes. Regular pectin depends on a large amount of sugar to help preserve the jam, so be sure to use the low-sugar variety when following a reduced-sugar method.

In this recipe you’ll combine fruit, lemon juice, pectin and sugar. Start by mixing the pectin with the lemon juice and 1/4 cup of the sugar, then add this mixture to the mashed strawberries in a large pot. Bring the mixture to a full, rolling boil over medium-high heat—one that does not fall when stirred—stirring constantly to prevent scorching. Add the remaining sugar (totaling 3 1/2 cups), stir well, and return to a full boil for one minute while continuing to stir.

Although 3 1/2 cups of sugar may still sound like a lot, it’s far less than many traditional jam recipes that call for twice that amount. The goal with low-sugar jam is to preserve the bright fruit flavor and keep the spread concentrated so you use less per serving.

After the second full boil (one minute), remove the pot from the heat and test for set. Spoon a small amount of jam onto one of the chilled plates from the refrigerator and let it cool for a minute. If the jam thickens to a texture you like, it’s ready. If it remains too runny, boil for an additional two minutes and test again. In rare cases you may need to add an extra 1/4 box of pectin and re-boil to reach the desired consistency.

Skim off any foam with a large spoon for a clearer appearance, then let the jam rest for about 10 minutes and stir gently to distribute fruit pieces evenly. This prevents the chunks from floating to the top once the jam is jarred.

Prepare your jar lids by making sure they are clean and free of dust. Fill the jars using a ladle and canning funnel, leaving about 1/4 inch of headspace at the top of each jar. Wipe rims with a clean, damp towel, place lids on the jars, and secure with the screw bands—don’t tighten them too firmly.

Place the jars on the rack inside the water bath canner and ensure water covers the jars by at least an inch. Process according to the altitude guidelines for this recipe: 5 minutes at sea level, 10 minutes above 1,000 feet, and 15 minutes above 6,000 feet. At the end of processing, remove jars with jar-lifting tongs and set them on a clean towel. Allow jars to sit undisturbed for several hours or overnight until they seal. A sealed lid will be slightly depressed in the center and will not flex when pressed.

Low-Sugar Strawberry Jam

Author: Marsha Maxwell

It’s easier than you think to make fresh low-sugar strawberry jam. This simple method preserves the bright summer flavor so you can enjoy it year-round.

Homemade jam makes a thoughtful gift and a delicious pantry staple. Try this low-sugar strawberry jam when strawberries are in season—you’ll capture their fresh flavor in a jar to enjoy later. If you make this recipe, please leave a note about how it turned out and any tweaks you tried.

Disclosures: The author was not compensated for this post. The original article may have included affiliate links; any referenced products are mentioned to help identify useful tools for home canning.

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