255 grams (1 cup) Chelsea White Sugar
250 ml (1 cup) water
Finely grated zest of 2 lemons
Juice of 5 lemons
1 egg white, whisked

Place the sugar and water into a saucepan over high heat. Stir until the sugar has dissolved, then remove from the heat.
Stir in the finely grated lemon zest and the juice. Allow to cool, then transfer to a container, cover and refrigerate for 1 hour.
Churn the chilled liquid in an ice-cream machine according to the manufacturer's instructions.
After 30 minutes of churning, add the whisked egg white to the sorbet mixture in the ice-cream machine and continue to churn until the sorbet is firm.
Serve or store in a covered container in the freezer.