In a blender, combine the soy milk, blueberries, sugar, vanilla extract, lemon juice, and salt.
Blend until smooth.
Pour the mixture into an ice cream maker and churn according to manufacturer's instructions. If you don't have an ice cream maker, you can pour the mixture into a freezer-safe container and freeze for 2-3 hours, stirring every 30 minutes until it is firm.
Once the yogurt has finished churning or is frozen, scoop it into a container and store it in the freezer until ready to serve.