Why parbake/prebake the crust?
As an addendum to my previous post, I wanted preemptively answer any questions that my readers may have about par/prebaking the crust for Key Lime Pie.
Pie crusts for creamy/custard pies are generally par/prebaked because:
1. Because the filling for the typical creamy/custard pie filling is very high in moisture, this helps keep the crust crispy & flaky. Not soggy.
2. Since creamy/custard pies are cooked at a lower temperature to keep the filling from overcooking, this ensures that the crust is cooked through.
3. Creamy/custard pie fillings typically have cooking times of less than 45 minutes. A par/prebaked crust will, again, ensure that the crust is done. Especially on the bottom.
4. Some creamy/custard pie recipes require no baking of the filling. Par/prebaked crusts are necessary since the filling isn’t cooked.
I hope this answers any questions any of you may have.