Ingredients

4 cups superfine brown-rice flour 

2/3 cup tapioca flour or starch 

1 1/3 cups potato starch 

Preparation

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; reseal and shake until well combined.