1.  Add together and simmer, uncovered,  for two hours:

3 lbs of grapefruit (chop roughly, take seeds out and stick in magimix to chop to the consistency of your choice)
3 lemons (same treatment as the grapefruit)
3 litres of water

2.  Add 1 jar of “wet” ginger, chopped, without the syrup (save that to pour over ice cream) and 6 lbs of sugar

3.  Boil until setting point has been reached (click here to read more on that) and bottle.  Yum.