Which ingredient is brushed on the bottom of an empty pie shell to prevent a soggy bottom?

• A. Milk
• B. Egg
• C. Butter
• D. Water

Answer: (B)

Preventing a soggy bottom comes from forming a moisture barrier on the inside of the crust. Brushing the empty pie shell with a thin layer of beaten egg (often just the white) creates a small, protein-rich film as it bakes. That film seals the crust and blocks juices from the filling from soaking into the dough, helping it stay crisp and well-browned. The egg white coagulates into a firm layer, unlike milk or water, which would introduce more moisture, or butter, which adds fat that can soften the crust. This simple barrier is a quick, effective way to protect the crust during baking.