There are just four simple ingredients in this homemade blueberry jam (no pectin required).
When I say this blueberry jam recipe makes a small batch of jam I really do mean a tiny batch. In fact, this recipe fills just one 4oz quarter pint jar. The perfect amount of homemade jam for one, a necessity in this home because I live in a house filled with blueberry haters. If you want to make a larger batch of jam the recipe is really easy to scale up.
With only a couple of simple ingredients the fresh sweet blueberries really shine in this jam recipe.
Making blueberry jam is one of the quickest ways to bottle up the last fresh berries of summer. This recipe takes just 20 minutes from start to finish.
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Blueberries: You can use either fresh or frozen blueberries.
Sugar: Nothing special here just plain granulated white sugar.
Lemon Juice: When blueberries and sugar are heated together, the blueberries begin to release pectin. The lemon juice bonds with the pectin, creating a gel that thickens your jam.
This is one time when bottled lemon juice is better than fresh lemons. Bottled lemon juice has a consistent PH. Fresh lemons vary in ripeness and PH making them unsuitable for setting jams.
Kosher Salt: Kosher salt helps to bring out the natural sweetness in the blueberries.
Small Saucepan: The cooking time for this recipe is based upon using a small saucepan. Using a larger saucepan increases the surface area, decreases the cooking time, but increases the risk of burning the jam.
Quarter Pint Jars: You could also store this jam in a plastic storage container, but I love the way the rich jewel tones of this jam catch the light in a glass container.
Potato Masher: A potato masher is helpful for smashing the blueberries and encouraging them to breakdown. You could also use the back of a spoon.
Prep. Place a small plate in the freezer to use for testing the jam. Wash and drain blueberries in a colander.
Cook the jam. Add blueberries, sugar, lemon juice, and salt to a small saucepan.
Bring to a boil and allow the blueberries to simmer and thicken for about 10 minutes. Gently smash the blueberries with the back of your spoon or a potato masher to encourage them to break down.
Test the jam. Take your frozen plate out of the freezer. Spread a small amount of jam across the frozen plate. The frozen plate will instantly cool the jam down so that you can determine how thick it is. Tilt the plate. If the jam slides across the plate quickly it needs to boil and thicken for longer. If the jam slides slowly it is done.
Spread one tablespoon of blueberry jam in the bottom of each ramekin. Refrigerate while you prepare the creme brulee. Store the remaining blueberry jam in an airtight container in the refrigerator for up to one month.
How do you know when jam is done?
As jam cools it thickens. To test a small amount of jam use the frozen plate method.
The frozen plate method
Spread a small amount of jam across a frozen plate. The frozen plate will instantly cool the jam down so that you can determine how thick it is.
Tilt the plate. If the jam slides across the plate quickly it needs to boil and thicken for longer. If the jam slides slowly it is done. If the jam doesn’t move at all it is over cooked.
Frequently asked questions
Yes, but frozen blueberries may be more tart than fresh blueberries so you may need to add more sugar.
In fact frozen fruit might be the better choice. Jam tastes best when it is made with high quality fruit. Fruit that is used for commercial freezing is always picked at peak ripeness.
Yes, as jam cools it will continue to thicken, which is why using the frozen plate method mentioned above is helpful to tell when a jam has been fully cooked.
Allow the jam to cool to room temperature and then pour it into an airtight container. Store in the refrigerator for up to one month.
Refrigerated jam should be good to eat for at least a month. Always use clean utensils to retrieve jam from the jar to avoid contamination. Signs of spoilage include mold or yeast growth, change in color, or any off odors like the smell of yeast, alcohol, or fermentation.
Refrigerator jam can be made with almost any variety of fruit. Feel free to use whatever is in season. You can also add fresh herbs or spices to change the flavors in your jam. Cinnamon, ginger, or mint pair beautifully with blueberries.
If you like to experiment with different flavor combinations I recommend the book The Flavor Bible by Karen Page. Thousands of ingredients are organized alphabetically and cross-referenced. Giving you delicious pairings for a variety of ingredients.
- Don’t overcook the fruit. Overcooked jam will be tough and rubbery. The mixture will seem too thin, but will thicken up as it cools.
- Boiling sugar can easily cause burns. Use caution and be careful to not splatter the mixture.
- If you want to add fresh herbs to your jam, add them at the end of the cooking process to preserve their bright flavor.
Jam has so many uses beyond toast. I love using this homemade blueberry jam as a topping for waffles and pancakes. It also tastes delicious on top of vanilla ice cream, scones, and stirred into plain yogurt, oatmeal, or a smoothie.
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