There are a few things I look for when determining if a pie is ready. First, the juices around the edges of the pie and in the very center should be thickened, syrupy, and bubbling with gusto. When I remove a pie from the oven, it almost looks like it’s breathing; the top crust (or lattice) moves ever so slightly, and is deeply golden. If the center of the pie is not bubbling but the crust is to your liking, cover loosely with a sheet of parchment or foil and continue baking for an additional 5 to 10 minutes. Underbaking is a common pie flaw, but one that is totally avoidable.