Plant starches play an important role in thickening soups, stews, sauces and desserts. Flour and cornstarch are handy choices, but potato starch, tapioca, rice flour and other alternative starches also work. When a recipe calls for cornstarch but you don't have any available, you may substitute rice flour in most cases.
Types of Rice Flour
Like wheat flour, rice flour is available in several types. The most common is derived from white long grain rice and is usually labeled simply as "rice flour." Mochiko, or sweet rice flour, produces a slightly stickier result and works best in sweet applications. Derived from short-grained glutinous rice, this starch is particularly useful for recipes you intend to freeze, because it prevents separation. Brown rice flour contains the whole grain and has a nuttier taste. it is more tan than other rice flours and can discolor sauces.
Substitute conventional or brown rice flour for cornstarch at a one-to-one ratio. Colorado State University recommends substituting sweet rice flour for cornstarch at a two-to-one ratio, however. Depending on the recipe, you may also be able to use the same amount of potato starch, arrowroot or tapioca flour.
Baking with cornstarch can be difficult at high altitudes. When you mix cornstarch with liquid and heat it, it may not reach temperatures high enough to start the thickening reaction. This problem also applies to rice flour. The University of Wyoming recommends using direct heat to make starch-thickened puddings and pie fillings that normally call for a double boiler.
In most applications, rice flour acts as a direct substitute for cornstarch, but it may not be ideal in all situations. Rice flour is a weaker thickener than cornstarch, so it might not be appropriate for gel candies and other applications where strength is important. Rice flour holds up better than cornstarch in acidic applications, however, and it has a higher gloss that makes it attractive for pies and other desserts.
- The Cook's Thesaurus: Starch Thickeners
- Colorado State University: Ingredient Substitutions
- Edinformatics: Science of Food Thickening Agents
- University of Wyoming: Altitude Adjusters
- Putting Food By; Ruth Hertzberg et al
- Sage V Foods: Rice Flour
- The Kitchn: What's the Difference? Rice Flour vs. Sweet Rice Flour
- Photo Credit Brand X Pictures/Brand X Pictures/Getty Images