Blackberry Jam - cooking recipe

Ingredients

3 lb. blackberries
3/4 c. mandarin juice
3 Tbsp. mandarin peel in syrup
7 c. sugar
3 Tbsp. lemon juice
6 oz. pectin

Preparation

`Put blackberries in a preserving kettle and cook until they are heated through.
Divide in half and put half the berries through sieve.
Return sieved berries to the kettle with whole berries and add sugar, mandarin juice, lemon juice and mandarin peel.
Stir mixture over high heat until it comes slowly to a rolling boil.
Boil hard 1 minute, stirring constantly.
Remove from heat and immediately stir in liquid pectin, skim foam off with a metal spoon, stirring to prevent fruit from floating.
Quickly ladle into hot, sterilized jars to 1/8-inch from top and seal immediately.