Since pie crust doesn't require any leavening agents, one would think that pies are, well, as easy as pie at high altitude. (Who came up with that expression "easy as pie" anyway? Many people shy away from making pie altogether because it intimidates them ... even at sea level.)
High altitude and dry mountain air do affect pies, but the effects are easily overcome. Add extra water while mixing up your pie crust to keep it from drying out too quickly (the recipe below includes that extra water). And since the higher you go, the less time required for liquids to boil, other adjustments need to be made or you'll end up with a too-brown crust and undercooked fillings.
The starches in berry and cherry pies need time to set up, longer than the time required to cook the fruit itself. Increase the baking time, but protect your crust with foil around the edges for the first 20 minutes or so of baking. (Some people prefer to put on the foil after the pie has baked for a while, but it's easier to take foil OFF a hot pie than it is to put in ON a hot pie.)
At sea level, it's best to use hard baking apples like Granny Smiths, but above sea level choose a softer apple like McIntosh or Golden Delicious for your pies. They'll bake more quickly and soften before the crust burns. At sea level, these types of apples tend to get mushy and more like applesauce than apple filling. Precooking the filling beforehand, as some bakers do, seems a bit extreme.
Crust: Ice cold water is one of the keys to a flaky crust. Fill a small bowl or measuring cup with water and 3 or 4 ice cubes. Set aside until needed. In a medium bowl, combine flour and salt. Cut in shortening using a pastry cutter or fork until pieces are the size of peas. Make a well in the center of the mixture to allow water to get to the middle of the dough. Sprinkle with cold water. Avoid mixing until all seven tablespoons of water has been added, and then gently stir just enough to distribute the moisture. Use your hands to do the bulk of the mixing, squeezing lightly to form a ball. Cut ball in half with a sharp knife. The less you handle the dough, the flakier the crust.
Sprinkle counter or other surface liberally with flour. Set half the dough in the middle, flattening slightly with your hand. Roll dough from center to edge with floured rolling pin to make a circle slightly larger than your pie pan. Gently roll dough onto rolling pin and unroll onto pie pan. Allow dough to hang about an inch over the pan; trim away excess with sharp knife.
Pour filling into crust.
Roll out second crust and position on top of filling. Trim if necessary, then tuck edge of top crust under bottom crust, pinching to seal. Make 5-7 small slits on top with sharp knife to allow steam to escape.
Tear off three 3-inch strips of aluminum foil and gently crumple around the edges of the crust to prevent over-browning. You can also tear off a length of foil slighly larger than
Pies may be one of the easier baked goods to adjust at high altitudes, since the major adjustment takes place in the pie crust. When making the crust, the most important thing is to balance the dry and wet ingredients for a flaky, crisp crust that will hold up well with pie filling.
Increase liquid. Pie crusts dry out more quickly at altitude and may need a bit more water to make the crust more pliable. Add water by the tablespoon until the desired texture is achieved; too much can toughen the crust by overworking the gluten. Typically the water should be ice cold for the flakiest crust.
Cover with foil. Because pie fillings take longer to bake completely when at high altitudes, it may be helpful to cover the pie loosely with foil during baking to ensure that the tops do not burn while the inside is completely cooking.
High altitude can wreak havoc on normally fabulous cakes and pies, but this is no reason to give up on them. Altitude is just a condition of the environment that might affect the outcome of a cake or a pie, just like temperature or moisture. A bit of experimentation and the right preparation is typically all it takes to come up with just as fabulous an outcome.
your pan, fold into fourths, cut out the center, unfold and use the resulting "frame" to lay over the top crust and crumple around edges. It's your call.