Scotch Marmalade

4 oranges
2 lemons
2 grapefruit
2 1/2 quarts water
7 pounds granulated sugar

Boil fruit whole in the water for 1/2 hour. Cool and remove pulp. Put skins and all through a grinder, then measure back into the pot and add water to make 3 quarts. Boil for 45 minutes. Add sugar. Boil again for 15 minutes. Put into sterilized jars and seal with paraffin. Serve with shortbread, scones or oat cakes.