Full disclosure: It was delicious yesterday when it was fresh, so good I almost could not stop eating it. This morning (yes, I eat pie for breakfast; judge me), the crust of the apple pie, which had been stored overnight on the counter, was still very good. The crust on the pumpkin pie, which had been stored in the refrigerator, had toughened. It still tasted good, but it had lost its delectable tenderness. I guess the moral of the story is: eat the whole pumpkin pie the first day. Shucks, huh?
I think there may be plenty of decent gf pie crusts if you use rice flour. The crust I developed was a take-off from rice flour recipes. Rice flour is not my favorite, for a number of reasons, some of which I will spare you (TMI), and also because it is tasteless. Tasteless. Textureless. Nasty. However, if you happily use rice flour, google Gluten Free Gigi and Amerca's Test Kitchens, and you will find nice pie crust recipes. Gigi takes out other allergens as well.
In my first attempt, I substituted 2 cups of oat flour for 1 cup of white rice flour and 1 cup of brown rice flour. The result was actually very pleasant. It was an apple pie, which I never refrigerated, and the crust held up nicely over the couple of days that the pie lasted. The flavor was buttery and delectable (I love oats). The texture sort of went to porridge in one's mouth as one chewed, which I did not find horrifying, but I wondered whether someone else might. Jonathan told me that he liked it that way, and that he thought it was better than regular crust. Indeed, it was a very nice crust. I underbaked the pie, by my standards, and the apples were not as soft as I like them. I also somehow put in too much nutmeg. (Why did I put in any nutmeg? I know I hate nutmeg in apple pie.) So in the end, the only reason I ate more than one piece of that pie was because I liked the crust.
However, the crust, though tasty, was rather viscous and swollen, in my opinion. As it baked, the fluting drooped down a bit over the edges of the pie plate. And the way the texture broke down to a moist, porridgey consistency during chewing indicated that this crust recipe could use something to make it a bit more firm and dry.
(pardon the unedited phone pictures)
I decided to try using 1 and 1/2 cups of oat flour with 1/2 cup of sorghum flour. This worked better than I ever imagined it would. Oh. My Word. That was some fabulous pie, out of the oven.
Here's my recipe:
GF Pie Crust
1 cup unsalted butter (2 sticks)
1 & 1/2 cups oat flour
1/2 cup sorghum flour
2/3 cup potato starch
1/3 cup tapioca starch
4 tsp. dry milk powder (you could leave this out; I forgot it the first time when I used 2 c. oats)
1 tsp. powdered psyllium (or 1/2 tsp xantham, but I had the psyllium on hand)
1 Tbsp sugar (if it is a dessert pie, or omit for chicken pot pie)
1 tsp. salt
6 Tbsp ice water
3 Tbsp sour cream
1 Tbsp apple cider vinegar
1. Cut the butter into small cubes and place on a plate or saucer in the freezer while you proceed with the next steps.
2. Measure ice water, sour cream and vinegar into a small cup and stir to mix. Set aside in an ice water bath, or refrigerate, or both. Also, keep the ice water handy because you may need more.
3. Place flours, starches, dry milk powder, psyllium, sugar and salt in food processor and pulse until well combined.
4. Scatter butter over the top of the dry ingredients and pulse until crumbs are uniform, about 25 times.
5. Add half of cold liquid mixture and pulse 3 times. Add the rest of the cold liquid and pulse about 20 times, until a ball forms. If it is not getting clumpy at all, you may need to add more ice water, 1-2 Tbsp at a time. It may not exactly form a ball, but it needs to clump up.
6. Divide dough into two pieces and form into disks about 5" in diameter. Wrap in plastic wrap and refrigerate at least an hour or up to 2 days.
7. If you refrigerated for a longer length of time, you may need to let the dough soften on the counter for 30 minutes before rolling it out.
8. Roll out between wax paper. You may want to dust the wax paper with something (this would be a way to use up your nasty rice flour).
9. I sprinkled some cornmeal in the bottom of the pie plate before laying in the crust. Bake as directed in your pie recipe.
10. This makes two one-crust pies, or one double-crust pie.