Blueberry Jam [No Pectin]

Cook the Blueberry Jam:
Place a small plate in the freezer for testing the jam later.
Stir the blueberries and sugar together in a large Dutch oven or heavy-bottom pot.
Bring the blueberries to a boil on medium heat and maintain at steady simmer for 30 minutes, stirring every few minutes to prevent burning on the bottom.
Skim and discard any foam on top while cooking.
After 30 minutes of cooking the jam, add the lemon juice and balsamic vinegar.
Cook for another 10-15 minutes or until the jam has turned thick with large tar-like bubbles. If you're using a thermometer, it should read about 218-220ºF (103-104ºC). This is the point when you want to test it to see if it's set.
3 lbs Blueberries, 3 TBS Bottled Lemon Juice, 2 TBS Balsamic Vinegar, 2 ¼ cups Granulated Sugar
Freezer Plate Test:
To test if the jam is set, spoon a small amount of hot jam onto the frozen plate and let it rest in the freezer for another minute.
Drag a finger through the middle of the jam. The jam is set if it wrinkles slightly and leaves a clear straight line through the middle without filling in. If it's still runny, then it needs to cook longer for the natural pectin to set.
Remove from the heat as soon as the jam passes the freezer plate test.
At this point, you can transfer the jam to jars and store in the refrigerator for 2-3 weeks if not canning.
Sterilize the Canning Jars:
If you haven't already sterilized your canning jars, you can do so while the jam cooks.
Boil the glass jars in a large canning pot with a wire rack with at least an inch of water covering the top of the jars for 10 minutes. Carefully empty and remove the jars from the water and set them on a clean towel until the jam is cooked.
Cover the hot water bath with a lid to keep the water warm.
How to Can Blueberry Jam (optional):
When the jam is set, place a wide-mouth funnel on top of the sterilized canning jars and carefully ladle in the hot jam (wear heat-proof gloves!). Leave ¼-inch of room on top and wipe the rims if any jam has splattered on them.
Place the canning lids on top and twist on the rings to fingertip tight.*
Boil the water in your water bath canner pot again and place the jams onto your canning rack. Slowly lower the rack into the water bath to cover them in at least 1-2 inches of boiling water.
Cover the pot with a lid and boil the jars for 10 minutes.**
Lift the hot jars from the water and let them cool completely at room temperature, undisturbed, for 24 hours. Within minutes, you should hear the satisfying pop of the canning lids sealing!***
Label and date the jars. The canned blueberry jam can last for a year in a cool, dark pantry but should be refrigerated once open.

Equipment

Ingredients

Instructions

Notes