A pie crust shield is a baking tool that covers the outer edge of a pie to keep it from over-browning or burning while the pie bakes. You can make one yourself by gently folding a piece of aluminum foil over the outside edge of a pie plate, but the advantage of the pre-made shield is that you never have to fuss with a hot pie and can simply drop it gently into place. Most shields are made from fairly lightweight steel or aluminum. Some are made from silicone and offer a finish that won’t stick to even messy pies and that is easy to clean. Both types will do the trick to keep your pie edges evenly – not overly – browned.
To use a pie shield, you can either place it on your pie before baking and remove it halfway through the baking time, or you can put it in place partway through the baking time to limit the browning.
I know some bakers who swear by pie shields and others who have never used them. I don’t typically use them much myself, as I find that I only need to cover my pie edges on very rare occasions and aluminum foil works well enough for me in those events. I love it when my pies get some dark color to them, especially along the edges, both because I like my crust to be crispy and because I simply enjoy the look of a pie that really looks like it has been hand-made. That being said, I do find that these are almost a necessity if your oven is older and has a lot of hot spots, because they really will keep the edges of your pie from burning and that is a great feature if your oven is a little unpredictable.