- In a blender combine raspberries, sugar, water, lemon juice, and vodka, if using. Blend on high speed until sugar is dissolved.
- Strain sorbet base through a fine-mesh sieve set over a medium bowl. Cover with plastic wrap and refrigerate overnight. Alternatively, pour base into a large zip-top plastic bag and submerge in a bowl filled with ice water. Agitate the bag occasionally until chilled, about 30 minutes.
- Taste the sorbet base and add a little more lemon juice if desired (the base should taste a little too sweet and tart, as the flavors will be less intense after freezing). Pour into an ice cream maker and freeze according to the manufacturer’s instructions.
- Scrape the sorbet into a loaf pan, press a piece of plastic wrap directly on the surface, and freeze until solid, 8 hours or overnight.
- Serve scoops garnished with berries.