01 - Combine water and sugar in a small saucepan. Heat over medium, stirring until sugar dissolves completely. Remove from heat and cool to room temperature.
02 - Stir in freshly squeezed lemon juice and lemon zest. Add vodka if desired and mix thoroughly.
03 - Pour mixture into a shallow freezer-safe container. Cover and freeze for 1 hour.
04 - Use a fork to break up ice crystals by scraping and stirring the mixture after 1 hour. Return to freezer.
05 - Continue scraping and stirring every 30 minutes for 3 to 4 hours until the sorbet is firm and fluffy.
06 - Scoop into small glasses or bowls and serve immediately as a palate cleanser between courses.