Here's Alton Brown's take on making Blueberry Soda (Pop):
Starts at 7:36
YouTube - Good Eats S11E11 Kinda Blue (2/2)
Here's the recipe
Ingredients
20 ounces fresh blueberries, approximately 4 cups, rinsed and drained
2 cups water
7 ounces sugar
1 lime, juiced
Carbonated water...