If you feel a bit apprehensive about the idea of canning, you’ve come to the right place. Our blueberry jam is a freezer jam, meaning there’s no finicky canning method required. We’ll show you how to make blueberry jam the easy way so you can eat your summer berries all year long. This recipe makes eight cups, so it makes a great food gift idea!
Ingredients for Blueberry Jam
- Blueberries: One of the most important aspects of preserving fruit is cleanliness. Wash the blueberries extremely well to remove any dirt, bugs or debris.
- Lemon juice: A bit of lemon juice balances the sweetness from the sugar and activates the pectin.
- Pectin: Pectin is a soluble fiber derived from plants. Its gelatinizing effect helps our blueberry jam recipe “set,” giving it the wobbly consistency you expect.
- Sugar: Yes, blueberry jam has a lot of sugar, but it’s there as more than just a sweetener. Sugar is used as a preservative, preventing future microbial growth in the jam. In other words, do not cut down the sugar or replace it with another sweetener.
Directions
Step 1: Clean the containers
The first step for any freezer jam recipe is to clean your containers very well so that they’re safe to store in the freezer and eat later. Start by rinsing five 1-cup plastic or freezer-safe containers and their lids with hot, soapy water. Dry them thoroughly.
Editor’s Tip: If you’re using glass jars, make sure they are wide-mouthed jars that were specifically constructed and tempered for canning purposes.
Step 2: Cook the jam
Mash the blueberries using a potato masher or fork. Transfer them to a Dutch oven, and stir in the lemon juice and pectin. Bring the mixture to a full rolling boil over high heat, stirring constantly.
Stir in the sugar and return the jam to a full rolling boil. Boil it for one minute, stirring constantly.
Editor’s Tip: Do not boil for longer than one minute or the jam could lose its gelling power.
Step 3: Skim the foam
Take the Dutch oven off the heat. With a large spoon, skim off and discard the foam. It’s okay if you miss a little, but try to get as much as possible.
Step 4: Add to the containers
Ladle the blueberry jam into the containers. You can use a canning funnel for less mess. Fill the jars to within a half-inch between the top of the jam and the top of the container. Cool the jam to room temperature in the jars, about one hour.
Editor’s Tip: This gap is called “headspace,” and overfilling your jars and not leaving enough headspace is a common canning mistake. You need to give the jam enough room to expand during storage to avoid cracking the jars.
Step 5: Let the jam set
Cover the containers with their lids and let them stand overnight or until set, but not longer than 24 hours. Refrigerate the jams for up to three weeks or freeze them for up to 12 months.
Recipe Variations
- Swap lemons for limes: Blueberry and lime is an incredible flavor pairing. You’ll get more sourness from limes than with lemons, which will cut the sweetness from the sugar. Add in the lime’s zest for an extra kick of brightness.
- Mix your berries: Swap out half of the blueberries for another berry. Blackberry is our absolute favorite!
- Add extracts and spices: Vanilla bean paste or extract is the easiest way to upgrade this blueberry jam’s flavor. Ground spices like cardamom, cinnamon or ginger pair perfectly with blueberries, too.
How to Store Blueberry Jam
To store the blueberry jam, refrigerate the jars for up to three weeks, or freeze them for up to 12 months. To thaw them from frozen, place the jars of blueberry jam in the fridge overnight.
Blueberry Jam Tips
Can I use frozen blueberries to make blueberry jam?
Yes, you can use frozen blueberries to make blueberry jam. No need to thaw them either; they’ll heat up when everything is cooked together in the Dutch oven.
What’s the difference between jams, jellies and preserves?
Jams, jellies and preserves all use the same general ingredients, but each is unique in its own right. Jelly only uses a fruit’s liquid and doesn’t contain actual pieces of the fruit itself. Jams contain the whole fruit, and the fruit gets broken down significantly during the cooking process. Preserves also contain the whole fruit, but the cooking process keeps the fruit’s structure to “preserve” the fruit’s shape.
