Seedless Blackberry Jam

5 from 2 votes

Servings: half pints

6 cups blackberry pulp, 8-9 cups of berries, mashed through a strainer with the back of a wooden spoon
4 cups sugar
2 teaspoons cinnamon
1 teaspoon freshly grated nutmeg
1 lemon, juiced and zested
1 packet liquid pectin, half the box

Prepare a canning pot with six half pint jars. Wash lids and rings and set aside.
In a large, non-reactive pot (stainless steel or enameled cast iron), combine the sugar and fruit pulp and bring to a simmer. Add cinnamon, nutmeg and lemon zest/juice and stir to combine.
Let the mixture reach a boil, stirring frequently to prevent it from boiling over. When the mixture appears to be thickening a bit, add the pectin and bring it back to a roiling boil.
Let it boil vigorously for at least five minutes to activate the pectin. Before removing from the heat, check the set using the plate or spoon test to ensure that the jam will firm up when cool.
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 lid from the pot and turn off the heat. Let the jars rest in the cooling water for five minutes. When that time is up, remove 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.