While an all purpose gluten free flour mix is generally okay for most baking and an easy choice, I am not a fan of all the rice flour and starches which may simulate texture and structure,
What's important to note when looking to create your own flour blend is that the ratio of grain flour (like brown rice, millet, sorghum or teff) to starch (like tapioca, arrowroot or potato starches) is generally 3 to 1, or 25% starch to 75% grain flour. This ratio will offer some softness, moisture and structure to your baked goods. Baked goods without the addition of starch may be too gritty, grainy and dry, and therefore way too crumbly. It takes a bit of time, investment and risk to get things the way you like. You may indeed find it easier to just go with a pre-packaged all purpose gluten free flour mix...I promise, I won't judge!
Regarding gluten free pie crust, I have made this many times with great success. If I've failed, it's because the dough was just too crumbly and impossible to work with. The remedy for crumbly dough is a bit of xanthum gum mixed with the four, or an egg...or both. If you do not want to add the egg, increase the xanthum gum.
And the final note for gluten free baking is the rest period. Since gluten free flours are often made with rice and other gritty grains, the absorption rate is much slower than wheat flour. Therefore most gluten free doughs and batters benefit from a short rest before baking, allowing the grit soften.
So take heart, my gluten sensitive friends, pie is back on the menu! And for one of the finest ways to try this crust recipe, my Strawberry Mango Galette is a real winner!
(yields a single crust, double this recipe for a double crust pie)
1 1/2 cups gluten free flour blend*
(* or make a blend of 1/2 cup sorghum flour, 1/2 cup brown rice flour, 1/4 cup potato starch, 1/4 cup tapioca starch)
1/8 tsp xanthum gum (optional)
2 tsp sugar (for savory pies and tarts, omit sugar)
1/2 tsp salt
7 Tbsp unsalted butter or coconut oil
1 egg (If you do not want to add the egg, increase the xanthum gum to 1/4 tsp and the water to 2-4 Tbsp)
1-2 Tbsp ice water
1 tsp vinegar or lemon juice
In a medium mixing bowl, stir together the gluten free flour(s), xanthum gum (if using), sugar and salt.
Cut in the butter or coconut oil until it becomes a coarse meal. Mix the egg (if using), the vinegar and half of the ice water. Mix the liquid into the flour mixture, adding more water if necessary, until it comes together into a ball. It should be a nice ball with visible streaks of butter or coconut oil. Wrap in plastic and allow to sit for 30 minutes. As the dough sits, it will continue to soften the grain and become finer in texture.
This dough is now ready for you to proceed with your recipe.