Raspberry Sherbet

Soften the gelatine in the cold water for five minutes. Make a syrup of the sugar and two cups of water. Simmer five minutes. Pour the sugar syrup over the crushed raspberries. Add the softened gelatine, and stir until dissolved. Pass the raspberry mixture through a fine sieve. Discard seeds. Puree mixture, adding lemon juice, lemon zest, and a large pinch of salt. Pour mixture into a shallow metal freezing tray. With freezer at its coldest setting, freeze until about an inch of the mixture is frozen. Remove sherbet from freezer and whip. Return to freezer. Later it is ready to serve.