Blind Baking: The term blind-baking (sometimes called “pre-baking”) refers to the process of baking a pie crust or other pastry without the filling.
Generally, the pie crust is lined with tin foil or parchment paper, then filled with dried peas, lentils, beans or other pulses, so that it will keep its shape when baking. Metal or ceramic pie weights are also used. After the pie crust is done, the pulses are replaced with the proper filling. Blind-baking is necessary if the pie filling can not be baked as long as the crust requires, or if the filling of the pie would make the crust too soggy if added immediately.
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