In a large mixing bowl, combine freshly squeezed orange juice, granulated sugar, orange zest, kosher salt, and vanilla extract. Whisk thoroughly for 2-3 minutes until the sugar dissolves completely and the mixture is smooth.

Gradually stir in milk and heavy whipping cream into the orange mixture. Mix until well blended and achieve a creamy consistency, about 1-2 minutes.

Pour the combined mixture into the pre-frozen bowl of your ice cream maker. Churn for 20-30 minutes until it reaches a soft-serve consistency.

Transfer the sherbet to a freezer-safe container, press plastic wrap directly onto the surface, and seal the container. Freeze for at least 4 hours or overnight until firm.