Blackberry Jam

4 cups blackberries
1 cup white sugar
2 Tbsp cornstarch
1/4 tsp ground cinnamon
1/4 tsp ground allspice
1/2 tsp lemon juice

1. Mash blackberries in a saucepan with a potato masher. Stir in sugar until juices form; place about 1 Tbsp blackberry juice in a small bowl and stir in cornstarch. Pour cornstarch mixture into saucepan.
2. Bring berries to a boil, stirring often, until jam is thickened, about 15 minutes. Stir in cinnamon and allspice. Remove from heat and allow to cool. Transfer jam to a bowl (or directly to a jar), cover, and refrigerate until chilled. Stir in lemon juice.

Try #1 - August 29, 2012
This was very good, and had the added bonus of not needing pectin!  Since I am a jam-making newbie, I don't normally have pectin lying around, but cornstarch is always in my pantry.  This thickened well, and tasted great!