1poundfresh or frozen blueberries (You will need 2 cups pureed berries)
4 cups sugar
1boxregular fruit pectin (1.75 or 2 oz box, depending on the brand)
1cupcool water
citric acid or lemon juice, to taste (optional)
Instructions
Start by thawing the blueberries if they are frozen. Then puree or mash the fruit until the desired consistency is reached. You will need 2 cups of crushed or pureed berries.
Stir the crushed blueberries and sugar together in a large bowl. Let sit for 20 minutes for the sugar to dissolve most of the way.
Towards the end of the 20 minute resting period you can start to cook the pectin. Empty the box of pectin into a small saucepan. Add in the water and stir well with a whisk to break up any clumps. Heat over medium high heat, stirring constantly, until it comes to a full boil. Boil for one minute then remove from heat.
Stir the hot pectin mixture into the blueberries. Whisk briskly for 1-2 minutes or until thoroughly incorporated.
Add citric acid, about ΒΌ teaspoon at a time, until desired taste is achieved. If using lemon juice, add it about a tablespoon at a time. Adding citric acid or lemon juice is optional depending on the sweetness of the berries you are using and your preferences.
Ladle the jam into small, clean jars or containers. Leave about half an inch of headspace between the top of the jam and the top rim of the jar. Once all the jars are filled, put the lids on the jars and transfer them to the refrigerator to cool and fully set.
After 24 hours the jam can be transferred to the freezer for long term storage. Thaw in the refrigerator for a day before use. Once opened use jam within three weeks or so. Jam keeps for up to 1 year in the freezer.