In the top of a double boiler, beat eggs and sugar until the sugar has dissolved.

Stir in the ruby grapefruit juice , ginger juice, butter and grapefruit peel.

Cook over simmering water for 15 minutes , stirring all the time so that it does not become lumpy.

Pour into glass jars and store in the fridge once cooled.

To Make ginger juice : Peel and grate the freshest piece of ginger you can find. Mash through a sieve to obtain the juice.