Here is another receipe idea for blackberries for you.

Stewed Blackberries

1 quart of blackberries
1 cup of sugar
1 cup of water
Pinch of salt

Wash the blackberries and pick them over, disgard any
that are mushy or green. Bring the sugar, water, and
salt to a boil and cook for 4 or 5 minutes. Add the
berries and simmer gently until they are just barely
cooked. Do not overcook or the berries will be mushy.
They should take about 8 to 10 minutes. Serve warm or
cold with cream.
Stewed blackberries can be served over icecream or with other
fruits.

I liked Eggy's receipes for using blackberries. They
were more creative than this one. Good luck!