- 2 pounds blackberries (7 cups)
- 3 1/2 cups sugar
- 2 lemons, halved
- 2 pounds raspberries (7 cups)
- 4 ounces kirsch or other cherry-flavored liqueur (1/2 cup)
- Bring blackberries, 1 3/4 cups sugar, and the juice of 1 lemon to a simmer in a large pot over medium heat. Cook until sugar dissolves and berries are soft, 4 to 5 minutes. Press parchment directly on surface of jam, and refrigerate overnight. Repeat with raspberries and remaining 1 3/4 cups sugar and juiced lemon in another large pot.
- Remove parchment; bring each pot to a boil. Cook over medium-high heat until berries are slightly broken down and jam is the consistency of very loose jelly, about 12 minutes for the blackberries and about 17 minutes for the raspberries. Plate-test jam to make sure it is set.
- Divide blackberry jam between four 1/2-pint-size sterilized glass jars, filling each halfway; top each with 1/2 ounce kirsch. Divide raspberry jam between jars; top each with 1/2 ounce kirsch, leaving 1/4-inch headspace at tops. Can in water bath for 10 minutes.