2 1/2 lb. blackberries
1 1/2 lb. sugar (or 3 c. sugar)

Wash berries thoroughly; remove caps and crush berries. Heat slowly to boiling, stirring constantly. Add sugar and continue cooking rapidly until mixtures give test to jelly. Pour into sterile jars and seal. If seedless jam is desired rub cooked berries through sieve before adding sugar. Makes 2 pints.