Use a zesting tool to remove the zest from the 5 oranges. Then, slice them in half and squeeze out all the juice into a measuring cup (you will need about 1 cup of juice). Combine the orange juice and the zest, 1 cup sugar, and 1 vanilla bean in a saucepan. Heat the mixture over medium high heat until the mixture starts to boil, then continue cooking while stirring for about one minute until the sugar has dissolved. Thoroughly chill the mixture in the refrigerator for a minimum of 2 hours to overnight.
Strain the mixture through a fine mesh strainer and discard vanilla bean and excess zest.
Combine the mixture with 2 cups buttermilk and process in an ice cream maker. If your mixture is cold and the ice cream vessel is very frozen (I keep mine in the bottom of my deep freezer), the sherbet will be perfect after about 45 minutes.
Notes
Recipe makes about 4 cups. Nutritional information based on 1/2 cup serving size.✔ Zest before juicing - It’s much easier to zest a whole orange than a squeezed one!✔ Freeze your ice cream maker bowl - Keep it in the back of the freezer for at least 24 hours before use.✔ For an extra flavor boost - Add a splash of Grand Marnier or a touch of orange extract.✔ Prevent ice crystals - Did you know adding a splash of vodka to the base can prevent ice crystals from forming?