Prepare the canner and put on the stove to boil. Heat jars in the oven or in hot water and place lids and rings in simmering water.

Combine the berries and lemon juice in a large, heavy-bottomed pot. Crush the fruit slightly with a potato masher. Sprinkle the pectin on top and mix in.

Bring to a full rolling boil over high heat, stirring constantly. Pour in all the sugar and return to a full boil. Boil for 1 minute. Keep stirring so the jam doesn’t scorch.

Remove the pot from the heat and remove any foam. Use a large spoon to skim it off and discard.

Using a ladle and funnel, divide the jam into 8 half-pint jars, leaving 1/4-inch headspace. Remove air bubbles with a clean knife, wipe the rims place lid and rings on the jars. Process for 10 minutes in a boiling-water canner.