To prepare currant pulp: Cook currants until soft; press through a sieve or food mill.
Combine currant pulp, raspberries and sugar in a large sauce pot.
Bring slowly to a boil, stirring until sugar dissolves.
Cook rapidly almost to jellying point, about 30 minutes.
As mixture thickens, stir frequently to prevent sticking.
Pour hot into hot jars, leaving 1/4-inch head space.
Process 15 minutes in boiling water bath.