A flat of freshly picked strawberries has an irresistible magnetic attraction to our family! The smell is so inviting and the taste is so rewarding! But the fresh picked season is too quickly come and gone.
Strawberry jam recipes are a great way to preserve the goodness of locally grown strawberries, and low sugar strawberry jam recipes are a very healthy way to enjoy the natural sweetness of strawberries all year round.
We tackled this flat of strawberries and turned them into ten pints of flavor rich strawberry preserves. It’s a fun and easy homeschooling project that results in a mouthwatering treat the whole family can enjoy! Here are our step-by-step instructions on how to make strawberry jam. We hope you will give it a try and let us know what you think.
Sterilize the Jars
One batch of low sugar strawberry jam yields about 5 pints. Consider how many batches you will be making and sterilize the appropriate number of jars. To sterilize jars, wash them in warm soapy water and rinse. Place jars in a large pot, cover them with water, and boil for 10 minutes. Jars can be left in the water bath until you are ready to fill them. Removing jars from hot water is much safer and easier with jar lifters, but regular kitchen tongs can be used in a pinch.
Prepare the Strawberries
As you rinse the berries remove the leaves and hull the berries. Hulling can be done with a knife, but a strawberry huller makes easy work of it.
For this recipe you will need six cups of fresh strawberries, sliced or cut into chucks, and slightly mashed (mashing releases the natural pectin in the fruit and aids in thickening). It takes about eight cups of whole berries to yield six cups of mashed. You could use the frozen variety if fresh strawberries are out of season, but be sure to get the kind with no sugar and no syrup.
Doubling jam and jelly recipes is not advisable because they do not gel properly when cooked in larger batches. If you have more than one batch to cook, it’s best to do it in several sessions.
Low Sugar Pectin
Low sugar pectin can be purchased wherever regular pectin is sold. It is very important that you buy boxes marked as ‘Low Sugar’ or ‘No Sugar Needed’ because the regular pectin product will not gel properly with reduced sugar recipes. Regular berry jams typically require about 7 cups sugar, but low sugar strawberry jam can be made with 4 cups of sugar or less by using low sugar pectin.
Tip: Separate a 1/4 cup of sugar and mix in one box of pectin plus an extra tablespoon of pectin from a second box. Dissolving this sugar/pectin blend into the strawberries ahead of the remaining sugar will help keep the pectin from becoming lumpy.
Using 4 cups of sugar instead of 7, saves about 21 calories per 1 tablespoon serving, yet the taste is still sweet and full of delicious strawberry flavor! You can reduce the amount of sugar even further and still achieve a proper gel by adding extra pectin to the mix. Just remember to buy an extra box for this purpose. We experimented with one batch and only used 2 1/2 cups of sugar. It tasted great, but we should have added two extra tablespoons of pectin because it was a little too soft for jam.
Now is a good time to heat the lids (or flats). Place them in a shallow pan, cover with water, bring to a boil, and allow them to boil for several minutes, until the rubber seal is softened. Leave the lids in the water until it is time to place them on the jars.
Fill a cup with ice water, place a metal teaspoon in it, and set to the side. This will be used to check the gel of the strawberry mixture before pouring it into jars.
Let’s Get Cooking!
Add the crushed strawberries to a heavy sauce pan, turn the heat up to med-high, and mix in the small bowl of sugar/pectin blend. Stir frequently as you heat the mixture to a full rolling boil that cannot be stirred down. Add the remaining sugar, return the mixture to a vigorous boil, and allow it to boil like this for about one minute. Stir continually to keep the strawberry mixture from sticking. After one minute of a rolling boil, remove mixture from heat.
The hard rolling boil produces a foamy surface on the strawberry mixture. This foam is mostly air, and it’s best to skim it off before pouring up your jam, but save the foam in a bowl because some jam can be recovered from it. It’s the perfect way to ‘taste test’ your recipe!
While the strawberry mixture is cooling, remove the jars from the sterilizing water bath, pouring any excess water back into the pot. Turn the heat back on under the water bath, and allow the water to return to a boil while you pour up the jam.
Remove the metal spoon from the ice water and scoop out a little of the strawberry juice. If it thickens on the spoon, the jam is ready to pour into jars … if it doesn’t thicken, add another tablespoon of pectin to the mixture, bring to a full rolling boil, and boil hard for one minute. The extra pectin and cooking time should help the jam set (gel).
Fill the Jars
Using a ladle, fill the jars to within a 1/4 inch from the top. Alternatively, you could use a funnel and pour the mixture into the jars, but I prefer to ladle into smaller jars because you can fill more slowly and make less mess.
Wipe the jar tops with a clean, dry cloth. Remove lids one at a time with a fork or a lid lifter. A lid lifter makes this job so much easier! Place the lid on the jar and tighten a ring around it. Using a jar lifter, place the jars back into the water bath. Make sure they are completely covered with water, an inch or two above the jars is sufficient. Bring the water to a boil and set your timer for 5 minutes. If you are at a higher altitude you may need to boil longer, check the instructions inside the pectin package for high altitude processing information.
After 5 minutes of boiling, remove the jars from the water bath and set them on a dry towel, being careful not to bump them together. Space the jars far enough apart to allow air to circulate between them. As the jars cool, the rubber on the lids will seal and the lids will be sucked down, making an audible POP. This is the sweet sound of success!