01 - Combine blueberries, sugar, lemon juice, lemon zest, and water in a small saucepan. Cook over medium heat, stirring occasionally, until blueberries burst and sugar dissolves, approximately 5 minutes.
02 - Remove saucepan from heat and allow the mixture to cool for 10 minutes.
03 - Transfer cooled mixture to a blender or food processor. Blend until completely smooth and no fruit chunks remain.
04 - Pour blended mixture through a fine-mesh sieve into a clean bowl, pressing with a spoon to extract liquid. Discard skins and seeds for smoother texture.
05 - Pour strained puree into a shallow freezer-safe dish. Place in freezer and freeze for 4 hours total, stirring vigorously with a fork every hour to break up ice crystals.
06 - Let sorbet sit at room temperature for 5-10 minutes before serving to soften slightly. Scoop into bowls or cones.