Nearly any unbaked fruit pie freezes well and retains a fresh fruit flavor. Unbaked custard and cream-based pies don't freeze well, because the crust becomes soggy. Unbaked pies that do freeze well include mince, nut and pumpkin. Utah State University's "Solving the Pie Puzzle" article recommends "apple, peach, blueberry, mince, strawberry or rhubarb" for freezing, but suggests that you bake cherry pie before freezing. When frozen, most pies retain freshness for three to four months, but pumpkin pies are best when used within four to five weeks.
Make the pie as usual, with the exception of fruit pies. For those, add 1/2 tbsp. cornstarch or 1 tbsp. tapioca or flour, which will thicken the filling and prevent the crust from becoming soggy. Adding thickener also prevents boil-over in the oven when the pies are baked.
Put the pie on a cookie sheet or baking pan, then place the pie in the freezer.
Remove the pie from the freezer as soon as the pie is frozen solid. Double-wrap the frozen pie in aluminum foil or plastic wrap, then slide the pie into a resealable plastic bag. Wrapping the pie after it is solid prevents the wrapping from damaging it.
Label the package. Note the type of pie and the date the pie was made. Include baking instructions, which will save time when you're ready to bake the pie. Return the frozen pie to the freezer immediately.
Cook frozen pies straight from the freezer and don't thaw them before baking. Cut slits in the frozen pie crust, then bake as indicated in your recipe.
To free up pie pans for other uses, remove the frozen solid pie from the pan just before you wrap the pie, then wrap the pie without the pan. Freezing pies without the pan also takes up less freezer space, as the pies are stackable. Place the pie in the pan when you're ready to bake it.
You can also freeze pies in disposable aluminum pie pans.