I have been inundated with requests for starch and flour substitutions for my recipes as well as recipes that originate from elsewhere. Today I’ll answer the questions on which gluten free starch substitute to use in different scenarios.
Also, see my Gluten Free Substitutions Page,
Gluten Free Baking with Starches
Starches lighten, inflate, and soften gluten free baked goods. It is always best to bake with 2 different types of starches. Each one provides something a little different. Using 2 different types of starch also improves flavor, as well as texture. In gluten free baking, you usually need to use gluten free flour(s), as well as starch(es). However, in some cases you will find that a recipe may call for just one flour such as glutinous rice flour, or sweet rice flour, which contain much starch. In rare cases, you will find the use of starch alone, without any flours, but this usually is called for when using yeast, such as in bread recipes.
When converting gluten recipes to gluten free, a high quantity of starch is usually needed to create a similar texture. Note that additional liquid is often needed because starches absorb more liquid than gluten flour. As you read below, you will discover which starches to use for which purpose.
Potato starch is known to lighten gluten free baked goods and provides a bit of a chew. Though potato starch does help aid baked goods in rising, it provides less of a rise than tapioca starch. Potato starch is best used in combination with tapioca starch. However, if you are tapioca intolerant, cornstarch is the best substitute, and Bob’s Red Mill makes one that is non-GMO (not genetically modified).
Note: Potato starch and potato flour are 2 separate ingredients. Starch is starch, chewy in texture, yet lighten baked goods. Flour is just that, though heavier than rice flour.
Tapioca flour/starch is known for its unique characteristics to lighten, inflate, and aid in browning, more than potato starch and cornstarch, and provides a more chewy texture. When used with yeast it speeds up the rising process and must be watched carefully. You never want to over-rise a bread for risk of it falling or caving in upon cooling. Cornstarch makes the best substitute for tapioca starch, though it lacks browning characteristics. It doesn’t rise as high as tapioca flour, but using a mixture of fava bean flour and cornstarch may be the best choice.
Note: Tapioca flour and tapioca starch are the same thing. They are just labeled differently by some manufactures. It is also known more commonly by tapioca flour, but also by cassava, yuca, aipim, mandioca, and boba.
Cornstarch is one of the lightest starches. Cornstarch is usually recommended as a substitute for potato starch. However, due to my allergies to tapioca I find it makes an excellent substitute for tapioca starch, as well. It does not, however, aid in rising as much as tapioca starch/flour. It also provides more crispness to your baked goods. They are very similar in weight, but cornstarch provides more flavor. As is with tapioca starch, when using cornstarch along with yeast, watch the rising period carefully, as it may over-rise and spill over the pan, ruining your bread. It all depends upon your other ingredients. If using cornstarch as a substitute for tapioca flour, I suggest adding additional leaveners such as baking powder or baking soda.
Corn in general, is not the healthiest of foods, however, if you are going to use it, I suggest using a non-GMO brand such as Bob’s Red Mill.
Corn and Potato Allergies
If are allergic or intolerant to both corn and potatoes, try substituting tapioca flour for either one, however, the recipe will be chewier. When large amounts of corn and/or potato starch are called for in a recipe, increase other gluten-free flours, such as sorghum, buckwheat, or millet, for a small portion of the potato or cornstarch. When a recipe calls for rice flour, because it is extremely high in starch (carbohydrates), do not increase the rice flour at all. Instead, use equal amounts of tapioca flour for potato or cornstarch. However, no matter what you use, the recipe will not result in the same texture.
Due to my allergy to tapioca, tapioca flour/starch (both are the same) is out for me. In addition, my digestive system is not fond of corn; therefore, cornstarch is not my best option. That leaves potato starch, arrowroot powder, and rice starch. Arrowroot is the easiest to digest out of all of the gluten free starches. It is known by the names arrowroot powder, flour, or starch. You will find many articles stating that arrowroot may be substituted for tapioca flour/starch cup for cup. While this is true, expect a couple of changes. Arrowroot powder absorbs more liquid than tapioca flour. This can result in either a better crumb texture or your baked goods will turn out too dry or heavy. When substituting arrowroot flour for tapioca flour, first substitute it cup for cup. If the batter or dough becomes too thick, add additional liquid as needed. Better yet, bake it as is, and discover if the crumb texture has improved.
My first experiment with arrowroot powder as a substitute for tapioca flour/starch was in my Gluten Free Oat or Sorghum Bread recipe. I was concerned at first. When I first opened the package the aroma of the arrowroot powder reminded me a little of anise or black licorice. However, when mixed with the oat flour, potato starch, egg whites, and other ingredients. I did not taste any difference in flavor compared to using tapioca starch. The rising time was about the same, as well. The differences I noticed were during the baking. It rose just a tad slower and not at all during the baking process. When using tapioca starch/flour, it continued to rise during the baking process. You need to allow the bread to rise to the desired height you would like in the finished product. In addition, the baking time had to be extended. My oat bread took 20 additional minutes.
As a side note, when baking bread, never bake it until it looks done as it must be baked past that point, at least in most recipes. You can always cover it with aluminum foil to prevent over-browning. How do you know when it is done? If it begins to sink in on the sides and/or bottom during the cooling process, pop it back in the pan and back in the oven for 15-20 minutes, or more.
But I digress. Back to arrowroot powder…Previously I had experimented with a gluten free rice bread recipe using only arrowroot and rice flour, no other starches, and egg white and water. I used half flour and half arrowroot. It turned out heavier than when using tapioca and potato starch. The person I was creating it for had a unusually long list of food allergies. It was edible but just starchier than my other gluten free bread recipes. I had followed the baking time for my original recipe, but have since learned it must be baked longer. The additional baking time helps dry out some of the starch.
If you are allergic to both corn and potato, in baking, use a ratio of two parts tapioca to one part arrowroot.
UPDATE: I have recently created a soft Gluten-Free Potato-Free Corn-Free Bread Recipe you may enjoy using arrowroot and tapioca flours.
Though rice starch is recommended for thickening sauces, I find it too grainy. I do not recommend it for this purpose at all.
Most starches used for thickening gravy become too thin once heated a second time or stored in the refrigerator or freezer. I find that an all-purpose gluten free flour containing added gums (xanthan or guar) works well for thickening gravy and sauces. However, the best and easiest to use is brown rice flour. It does not create lumps in your gravy, and all you have to do is sprinkle it in the sauce. There is no need to create a slurry with water. You may also use white rice flour. Because brown rice flour is less gritty, I tend to you use it instead of white. The only difference is that with brown rice you only have to cook it for 2 minutes, just as you do with wheat flour. White rice tends to take about 3 minutes.
Again, I digress. I used rice starch in a bread recipe once; however, it was not pleasant at all. It turned out exceptionally heavy and extremely chewy, more so than the arrowroot powder. I do plan to experiment with it on its own as it contains flour and starch properties, much like sweet rice flour.
If you can tolerate tapioca starch and potato starch, together they make the best combination for gluten free baking. If you must use a substitute for either, use cornstarch. Cornstarch the best starch to use on its own, without any gluten free flour. If you decide to avoid all of the above starches use glutinous rice flour, also known as sweet rice flour.
Due to the high amount of starch in gluten free food, consider using more whole grain flours such as sorghum, brown rice, millet, teff, and more.
To learn more about the science behind starches visit http://www.foodproductdesign.com/articles/1996/01/understanding-starch-functionality.aspx.