This is a flexible berry jam recipe that can be used for blackberries (and blackberry relatives), cranberries, elderberries, raspberries, and blueberries. If using half-ripe blueberries, at the red instead of blue stage, the result is a jam far more flavorful than usual—almost like one made with Scandinavian lingonberries. Depending on the tartness of the fruit, you may or may not need to add lemon juice. Add it to taste. Please read How to Process.

Prepare a water-bath canner, gather all your canning equipment, place a couple of saucers in the freezer, and have ready 5 clean, hot half-pint jars.

Combine in a wide, heavy pot or Dutch oven:

Bring to a boil, crushing one-quarter of the berries in the pan. Boil, stirring frequently, until it reaches the jelling point. Remove from the heat and skim off any foam. Ladle into prepared jars, leaving ¼ inch headspace. Wipe the rims. Place lids on jars and screw on rings until fingertip-tight. Process for 10 minutes. Let cool completely and store as directed.