To avoid a runny blueberry pie, use smaller berries, use tapioca flour as a thickener, and allow the baked pie to cool as instructed in the recipe! It is important that the pie cooks as long as directed. If it has a crust and seems to be browning too fast, tent the top with aluminum foil. If your pie still has some excess liquid after cutting it, just spoon it out or soak it up with paper towel