Source: The Martha Stewart Show, March 2010
- 4 cups superfine brown-rice flour
- 2/3 cup tapioca flour or starch
- 1 1/3 cups potato starch
To measure brown-rice flour and tapioca flour, use a large spoon to scoop flour into a measuring cup, then level it off with the back of a knife. Do not use the measuring cup itself to scoop your flour when measuring; it will compact the flour and you will have too much for the recipe.
Add both flours to a large resealable plastic bag, along with potato starch and tapioca flour; reseal and shake until well combined. Keep refrigerated until ready to use, up to 6 months.