Prepare a canning pot and 5-6 quarter pint jars.

Wash the blueberries and pick them over for stems and leaves. Pour them into a wide, non-reactive pot and add the sugar, pectin, cinnamon, nutmeg, and lemon zest and juice.

Using a potato masher, break up the berries and work in the spices.

Place the pot on the stove over high heat and bring to a boil. Reduce the heat to medium-high and cook, stirring regularly for 15-20 minutes, until the jam passes your set test of choice.

When you're satisfied with the consistency of the jam, remove the pot from the heat. Funnel the jam into the prepared jars, leaving 1/4 inch headspace.

Wipe the rims, apply the lids and rings, and process in a boiling water bath canner for 10 minutes.

When the time is up, remove the jars and set them on a folded kitchen towel to cool. When the jars have cooled enough that you can comfortably handle them, check the seals. Sealed jars can be stored at room temperature for up to a year. Any unsealed jars should be refrigerated and used promptly.