Watermelon – 1.4 kg (seeded, peeled and cut into cubes)
Castor sugar – 100 gms
Finely grated zest and juice of one large orange
Finely grated zest of ½ lemon
Lemon juice – 1 tbsp
- Puree watermelon, in batches, in a blender, or crush to a pulp with a potato masher, then work the pulp through a nylon sieve.
- Put the sugar into a large bowl with the orange and lemon zest. Slowly stir in the orange and lemon juice.
- Add the watermelon puree, a little at a time, stirring constantly to dissolve the sugar.
- Pour the mixture into a 1 litre rigid polythene container and freeze, uncovered, for about 3 hours, or until the mixture is slushy.
- Turn the mixture into a large bowl and whisk to break up large ice crystals. Return to the container, cover and freeze for a further 2-3 hours, until firm.
- Transfer to the main part of the refrigerator and leave for 1 – 1 ½ hours, until softened.
- Mash the ice briefly with a fork to break up large lumps, then spoon into dishes and serve at once before it begins to melt.