Berry Buttermilk Sherbet

from Cooking Light

2 1/2 c. blackberries (I used raspberries; I think any berry would do.)
1/2 c. sugar
1 1/4 c. low-fat buttermilk

Combine blackberries and sugar in a blender or food processor; process until smooth. Strain blackberry mixture through a fine sieve over a bowl; discard solids. Stir in buttermilk.

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 4 hours or until firm.