How can I keep my blueberry pie firm without the flavor of corn starch? In the summer, I often make a refrigerated blueberry pie. The recipe calls for a graham cracker crust, and you make the filling by cooking one pint of blueberries with one cup of sugar and 3 tablespoons on cornstarch on the stove until the mixture becomes thick. It's then poured into the crust, and topped with another pint of fresh blueberries, and chilled until it's firm. 

The flavor of the blueberries is delicious, but I always find that there's a pronounced corn starch flavor that detracts from the simplicity of the pie. How could I change the recipe or the technique to decrease that flavor while maintaining the firmness of the filling?
you could try some other thickeners, like xanthan gum, tapioca starch, arrowroot, or the like. not certain of the proportions, though, but i'm betting google knows.