Blind-baking

Blind baking a pie crust is necessary when it will be filled with an unbaked filling (such as with pudding or cream pies), in which case the crust must be fully baked.

[1] Blind baking is also used to keep pie crust from becoming soggy due to a wet filling.

In one technique, the pie crust is lined with aluminium foil or parchment paper, then filled with pastry- or pie weights (sometimes called "baking beans") to ensure the crust retains its shape while baking.

Pie-weights are available as ceramic or metal beads, but rice, dried peas, lentils, beans or other pulses can be used instead.

[1] A further simplified technique involves piercing the crust repeatedly with the tines of a fork to produce small holes, allowing steam to escape and preventing the crust from bubbling up, but that does not work with soft doughs such as pâte sucrée.

Pie shell after blind baking
A close-up photograph of ceramic pie weights