We have lots and lots of Blackberries and Raspberries this year. They are so plump, juicy and delicious this year. I was looking for a way to use them up and I found the following recipe for Raspberry Jam on the Kraft website. It should work equally well for Blackberries.
6 cups of fully ripe berries
5 1/4 cups sugar (measured into separate bowl)
3/4 cup water
1 box Sure Jell Fruit Pectin
Rinse clean plastic containers and lids with boiling water. Dry thoroughly.
Crush berries thoroughly, one layer at a time. (Press half of pulp through a sieve to remove seeds, if desired.) Measure exactly 3 cups crushed berries into large bowl. Stir in sugar. Let stand 10 minutes, stirring occasionally.
Mix water and pectin in small saucepan. Bring to a boil on high heat, stirring constantly. Continue boiling and stirring for 1 minute. Add to fruit mixture; stir 3 minutes or until sugar is almost dissolved and no longer grainy. (A few sugar crystals may remain.)
Fill containers immediately to within 1/2" of tops. Wipe off top edges of containers; immediately cover with lids. Let stand at room temperature 24 hours. Jam is now ready to use. Store in refrigerator up to 3 weeks or freeze extra containers up to 1 year. Thaw in refrigerator before using.