How to Make Blueberry Pie
The filling is the star of blueberry pie. We'll show you the tell-tale sign that your filling is ready to come out of the oven. (Hint: It's not about setting a timer.)
-The secret to blueberry pie is simple. It's the bubbles. That's right. The real secret is to watch for the filling to bubble at the end of the cooking time. I'm not saying that you should blow off your kitchen timer, but keep an eye out for bubbles to slowly develop, erupt and dance across the entire surface of the pie. If the top crust has slits, you should see the filling gently pop up through the holes. Don't pull it too early. Generally, the bubbles will form around the outside edges first and work their way towards the center.