1 ½ cups sorghum flour (or brown rice flour)
1 ½ cups potato starch (not potato flour) or cornstarch
1 cup tapioca flour/starch
Whisk together thoroughly and store, tightly covered, in a dark, dry, cool place.
Wondering how to measure flour? Here’s how:
All of the recipes in my books measure dry ingredients by whisking the flour a few times to aerate/fluff it and then lightly spooning it into a measuring cup before leveling it off with a knife. Don’t use the measuring cup as a scoop; you’ll get up to 20% more flour that way and don’t pack the flour down into the cup. Don’t use the glass, spouted measuring cups (which are for liquids) to measure dry ingredients like flour or sugar because you may get more than necessary.
If you use too much flour, your baked goods can be dry and crumbly instead of tender and moist… so measure correctly!