How to Make It
Combine first 3 ingredients in a saucepan, stirring until sugar dissolves. Bring to a boil; boil 2 minutes. Remove from heat; let stand 30 minutes. Pour syrup through a fine sieve into a bowl; discard solids. Stir in buttermilk, rind, and salt; chill 1 hour.
Pour mixture into the freezer can of an ice-cream freezer; freeze according to manufacturer's instructions. Spoon sherbet into a freezer-safe container; cover and freeze 1 hour or until firm. Garnish with lemon rind strips, if desired.