No matter how long the recipe says to cook, if the pie is not bubbling over, it is not done. If the crust and crumb appear to be getting dark before the fruit bursts and bubbles, use an aluminum foil shield to extend the cooking time. If the pie is not bubbling, it is not done.
Ideas in Food: Great Recipes and Why They Work
Maximum Flavor: Recipes That Will Change the Way You Cook
Gluten Free Flour Power: Bringing Your Favorite Foods Back to the Table