¼tspcoarse Kosher salt(if using table salt, use half the amount)
2tbsp"classic" powdered pectin(more pectin may be needed to set the jam, depending on the brand)
2cupsgranulated sugar
1tspvanilla extract
1tspunsalted butter
Instructions
In a large stock pot, combine the blueberries with the lemon juice, spices and salt.
Over medium heat, bring the fruit to a simmer, and simmer for a few minutes until soft and juicy. Mash the blueberries slightly, but be sure to leave whole berries, too.(If you're using wild blueberries, you probably don't need to smash them at all, but with larger cultivated blueberries, you'll want to smash some of them to thicken the texture of the preserves.)
Sprinkle the pectin over the bubbling fruit, and stir it in, then add the sugar. Increase the heat to high, and bring to a vigorous boil, while stirring constantly (wear an oven mitt to protect your hand against splatter and steam burns). Once the fruit is boiling hard enough that the bubbles can't be stirred down, continue to boil and stir for 1 full minute. This boiling process activates the pectin to "set" the jam. Remove from the heat and stir in the vanilla and butter (to reduce any foam).
Immediately ladle the hot jam into clean jars. Wipe the rims of the jars clean, and screw on the lids.
Notes
Note: If you can't get wild blueberries, regular blueberries (fresh or frozen) also work great in this recipe.Storage Tips
Refrigerator: If eating the jam right away, you can store it in the refrigerator for up to 1 month.
Pantry: To store the jam at room temperature for up to 18 months, like in your pantry, or to give away as gifts, be sure to can the jars of jam in a hot water bath, according to standard canning procedures. This ensures the lids are properly sealed to protect against contamination.
Freezer: If you want to avoid canning the jam, and you have the freezer space, you can simply freeze the jars of jam for up to 12 months. To store the jam in the freezer, be sure to leave 1/4 inch "head space" at the top of the jars to allow for expansion as the jam freezes. Thaw out in the refrigerator overnight before eating.