Sourdough baking has its own learning curve. Learning to work with a natural leavening agent versus commercially produced yeast is a challenge in its own right. But when entering the world of gluten-free sourdough baking, there are literally dozens of flours to choose from, complicating things even more.
WHY MORE THAN ONE GLUTEN-FREE FLOUR?
Many gluten-free recipes call for several flours, generally because each replicates some property in wheat-based baking. Some flours are higher in starch, while others contain more protein. Combining them creates better texture in baked goods.
The key to substituting one gluten-free flour for another is to understand what role each flour plays in the recipe. It is helpful to categorize these flours, to know which ones are similar and which ones are different.
While two flours might exist in the same category, they will not always produce the same result. For that reason, do not assume that by substituting one for another in the same category, you will get exactly the same results. Instead, these categories can be thought of as a roadmap to better gluten-free sourdough baked goods. Experiment with these substitutions and then tweak them to make them better.
GLUTEN-FREE FLOUR Categories
High-starch content in a recipe can often help to mimic white flour baked goods. But using a little bit of these flours, in combination with ones in other categories, will help to create lighter gluten-free sourdough baked goods. Each of these has its own properties, so combine them to take advantage of their benefits.
- Arrowroot Flour
- Potato Starch (not flour!)
- Tapioca Starch/Flour
The flours in this group are often higher in protein and higher in fiber, so they are a good choice for those looking to achieve a more wholesome baked good. However, they can also produce a dense, heavy finished product. Therefore, combining a heavy flour with a starch or all-purpose flour is often preferred.
- Bean and legume flours
- Amaranth flour
- Buckwheat flour
- Millet flour
- Quinoa flour
- Nut and seed flours
- Teff flour
If there are any flours that come close to being fairly neutral, these would be the ones. Much like all-purpose wheat flour, the flours in this category are often considered a foundational flour, being used in larger amounts than others.
- White rice flour
- Brown rice flour
- Oat flour (certified GF)
- Sorghum flour
Finally, there is one flour that does not share characteristics with any of these flours, and that is coconut flour, which is incredibly high in fiber, and as such doesn’t even belong in the “Heavier Flours” category.
Small amounts of coconut flour can be used in place of a part of the heavier flour measurement, but it should not be substituted 1:1 in baking.
Don't Be Afraid to Experiment
Within each of these categories, variation can occur. Expect some differences when making substitutions.
One of the most common pieces of advice in gluten-free baking is to make substitutions by weight, not volume. Because each flour has its own density, weighing will produce a more exact result.
That said, experiment with cup-for-cup substitutions and use this guide as your road map to better gluten-free sourdough substitutions.