6 cups of smashed blueberries (you’ll need 8-10 cups of unsquashed berries to equal this amount)
4 cups sugar
3 tablespoons classic pectin powder
zest and juice of 1 lemon
1 teaspoon cinnamon
1/2 teaspoon grated nutmeg
Prepare a canning pot and 3 pint jars. Place 3 lids in a small saucepan and bring to a bare simmer.
Pour the smashed berries into a low, wide, non-reactive pot. Measure out the sugar and whisk in the powdered pectin. Add the sugar and pectin mixture to the fruit and stir to combine.
Once the sugar is mostly dissolved, place the pot on the stove and bring to a boil. Cook at a controlled boil for 10 to 15 minutes, until the fruit begins to look thick and any foaming has begun to subside.
Add cinnamon, nutmeg, lemon zest and juice and let jam continue to cook until it passes the plate test, or until the drips hang off the spatula in thick, sticky rivulets.
Remove jam from heat and funnel into prepared jars. Wipe rims, apply lids and rings, and process in a boiling water bath canner for 10 minutes.
When time is up, remove jars from canner and place them on a folded kitchen towel to cool.
Once jars are cool enough to handle, remove rings and test seals.
Sealed jars can be stored on the pantry shelf for up to one year. Any unsealed jars should be refrigerated and used promptly.