Wash the grapes, remove the stems and squeeze the pulp from the skins into
a preserving kettle. Put the skins on a granite plate and save them. Boil
the pulp until the seeds separate easily, stirring constantly. Strain
through a sieve, add the skins to the strained mixture, measure, return to
the kettle, and add an equal amount of sugar. Boil gently for 15 minutes
or until the jam is very thick. Pour into sterilized glasses and seal when
cold. The mixture needs careful watching and stirring, as it will burn
easily, especially after the sugar is added.
[DOMESTIC SCIENCE 825]