Rice flour (also rice powder) is a form of flour made from finely milled rice. It is distinct from rice starch, which is usually produced by steeping rice in lye. Rice flour is a particularly good substitute for wheat flour, which causes irritation in the digestive systems of those who are gluten-intolerant. Rice flour is also used as a thickening agent in recipes that are refrigerated or frozen since it inhibits liquid separation.
Rice flour may be made from either white rice or brown rice. To make the flour, the husk of rice or paddy is removed and raw rice is obtained, which is then ground to flour.
In Japanese, rice flour is called komeko (米粉?) and is available two forms: glutinous and non-glutinous. The glutinous rice is also called sweet rice, but despite these names it is neither sweet nor does it contain gluten; the word glutinous is used to describe the stickiness of the rice when it is cooked. The glutinous variety called mochigomeko (もち米粉?, or mochiko for short) is produced from ground cooked glutinous rice (もち米 mochigome?) and is used to create mochi or as a thickener for sauces. Another variety called shiratamako (白玉粉?) is produced from ground uncooked glutinous rice and is often used to produce confectioneries. The non-glutinous variety called jōshinko (上新粉?) is made from short-grain rice and is primarily used for creating confectioneries.