Jams don't have to be full of sugar -- try this lower-sugar recipe if you're looking to cut some sugar from your diet. Full of raspberries, blackberries, and blueberries, losing some sugar doesn't mean losing flavor.
Place 1 cup of the raspberries in a 6- to 8-quart heavy pot crush. Use a potato masher to crush berries. Continue adding all the berries and crushing until you have 6 cups crushed berries. Stir in champagne and lemon zest. In a small bowl stir together 1/4 cup of the sugar and the pectin; stir into berry mixture.
Bring berry mixture to a full rolling boil, stirring constantly. Stir in the remaining 4 1/4 cups sugar. Return to a full rolling boil, stirring constantly. Boil hard 1 minute, stirring constantly. Remove from heat. Quickly skim off any foam with a metal spoon.
Ladle hot preserves into hot, sterilized half-pint canning jars, leaving a 1/4-inch headspace. Wipe jar rims; adjust lids and screw bands.
Process filled jars in a boiling-water canner 10 minutes (start timing when water returns to boiling). Remove jars from canner; cool on wire racks.