First, to prepare for your sorbet, place the bowl from your ice cream maker into the freezer. Freeze for at least 24 hours for the best results.
In a blender, puree fresh or thawed frozen raspberries. You may need to shake up or use a spatula to scrape the sides and puree all the berries.
Once your berries are pureed, strain the mixture through a mesh sieve to remove seeds.
Rinse the blender to remove any seeds, and pour the strained mixture back into the blender. Add sugar, lemon juice, lemon zest, and salt. Blend for another 30 seconds until combined and sugar is dissolved. Pour into a bowl and cover with plastic wrap. Chill mixture in the fridge for about 2-4 hours.
Once your mixture is chilled and your ice cream maker bowl is frozen, place the frozen bowl back into the machine. Turn ice cream maker on, and pour your mixture into the ice cream maker.
Set your timer for about 25 minutes. As the ice cream maker turns the mixture will get more chilled and begin to create a creamy texture. At about 12 minutes you will see the sorbet start to thicken. Once your ice cream is made, place it in a storage container, cover with plastic wrap and freeze until your sorbet is at the desired firmness.