This freezer jam is like a baby step version of canning. Because you never bring the jam to a boil and store in below zero temperatures, you lessen the chances of accidental contamination or heat-related mishaps. Rather than sweat over a stove, my grandma uses this method to make jam for friends and family.
One note: Freezer jams always run a little thinner than heat-processed preserves. Give them time to set to a nice, spreadable consistency. —Katie Macdonald