4 cups superfine brown-rice flour (recommended: Authentic Foods brand)
1⅓ cups potato starch (not potato flour)
⅓ cup tapioca flour (also called tapioca starch)
Measure the flour using a large spoon to scoop the flour into the measuring cup, then level off with the back of a knife or straight edge.
Combine all ingredients in a gallon-size plastic bag. Shake well to blend. Store in the refrigerator.
Makes six cups.
"The Allergen-Free Baker's Handbook" by Cybele Pascal (2009 Celestial Arts)