Strawberry Jam

This strawberry jam is the easiest to make with minimal sugar and no packaged pectin. It has a soft, velvety texture, bursting with fresh strawberry flavor, and spreads beautifully!

 

This homemade strawberry jam recipe is perfect when strawberries are in season! It's excellent on sourdough biscuits or toasted sourdough English muffins.

We love to use this strawberry jam as a filling in sourdough pop tarts or hand pies too.

Juicy, ripe strawberries are mixed with sugar and left to sit for an hour or more to release their natural juices. This step, called macerating the fruit, softens the berries, dissolves the sugar, and reduces cooking time, preserving that fresh strawberry flavor.

This low-sugar jam recipe has just the right amount of sweetness, letting the strawberry taste shine. The jam naturally thickens with apple pectin and can be kept in the fridge for up to 2 months. With bottled lemon juice, it’s also safe for water bath canning.

Ingredients needed

This recipe makes about 5 half-pint jars of homemade jam.

• fresh strawberries
• sugar: Granulated sugar
• Lemon juice: Use bottled lemon juice if you canning the jam or fresh juice if you plan to store it in the fridge.
• Granny Smith apple: These apples have high levels of pectin.

Equipment needed

• large mixing bowl
• measuring cups and spoons
• box grater
• large stockpot (at least 5.5 quarts)
• large heat-safe spoon for stirring hot jam
• half-pint glass jars or quart glass jars with lids and rings
• small glass plate (to test jam for doneness)
• jar funnel
• ladle
• digital thermometer or candy thermometer
• optional: water-bath canner and canning equipment

How to make strawberry jam

Place a small glass plate in the freezer. You'll use it later to test the jam for doneness.

Step 1: Prepare the strawberries

Wash 3 lbs. of fresh strawberries, remove the stems, and chop them into small pieces. Crush the fruit with your hands or a potato masher, then measure out 6 cups of crushed strawberries into a large bowl. Stir in 3 cups of granulated sugar and let the mixture sit for 1 hour on the counter.

Step 2: Prepare the jars

According to the National Center for Home Food Preservation, jars processed in a water-bath canner for 10 minutes or more don't need to be pre-sterilized, but they still need to be hot when filled with jam to avoid temperature shock.

Wash the jars, lids, and rings with hot, soapy water, making sure to rinse them well. Place the clean jars in your water bath canner and cover them with water. Let the water simmer while you cook the jam to keep the jars hot.

Step 3: Grate the apple

After the strawberries and sugar are macerated for one hour, peel, core, and grate 1 medium apple and add it to the strawberries with 2 tablespoons of bottled lemon juice.

It's important to use bottled lemon juice to ensure the jam's acidity or pH level is safe for canning. (If you are not canning the jam, you can substitute fresh lemon juice.)

Step 4: Cook the jam

Transfer the mixture to a large stockpot, 5.5 quarts or larger, and bring it to a boil over medium-high heat.

Once it reaches a rolling boil that can't be stirred down, set a timer for 20 minutes. Stir constantly to prevent the jam from boiling over. Test the temperature of the jam with a digital thermometer; it should register between 212-216°F (100-102°C) at a rolling boil.

As the mixture thickens toward the end of the cooking process, the foam will start to subside.

Once the timer goes off, turn off the heat and test for doneness.

Step 5: Test the jam for doneness

Remove the glass plate from your freezer when you're ready to test your jam. Drop a spoonful of the hot jam onto the cold plate. Return the plate to the freezer for 2 minutes. Remove the plate and run your finger through the jam. If the jam stays separated, it's ready! If the jam oozes back together, cook for 5 more minutes and retest.

Step 5: Transfer the jam to containers

Before filling the jars, skim any foam from the top of the jam using a large spoon. Use a jar funnel and a ladle to fill the hot jars, leaving a ¼" headspace—screw on the lids and rings.

If you plan to store your jam in the fridge, you can use larger jars, such as pint or quart size.

Canning Instructions

Properly preserved jam can be stored unopened on your pantry shelf for 18 months or longer. It's very easy and doesn't take much time at all!

If there is not enough jam to fill the 5th half-pint jar within a ¼" of headspace, simply store it in the fridge. Do not process it in the canner, as it will not seal properly, and consume it within 1 month.

Step 7

Ensure the jars are covered by at least 1 inch of water, cover the pot, and bring to a boil. 

Once it’s at a rolling boil, start your processing time. For altitudes 1,000 ft above sea level or lower, process half-pint jars for 10 minutes. See our guide to water-bath canning for an altitude adjustment chart. Adjust your processing times accordingly.

After processing the jars, turn off the heat and remove the lid. Let the jars sit for 5 minutes before removing them from the canner.

Use a jar lifter to remove the jars and place them on a heat-safe surface, covered with a kitchen towel, undisturbed for 12-24 hours.

Step 8

Remove the rings and check the seals. The lid should be indented, and you should not be able to take it off. If a jar does not properly seal, store it in the fridge for up to 2 months.

Wash and label the jars with the contents and date.

Canned foods should be kept in a pantry between 50-70°F (10-21°C) for best long-term storage results.