Cookbook:Gluten-Free Flour

Gluten-Free Flour
Gluten-Free Flour
Category	Flours

Gluten-free flours are those made without gluten-containing grains like wheat, rye, and barley. They are typically used to replace wheat flour when baking for people who cannot eat gluten.

Characteristics

Gluten-free flour can be made from any flour or starch that does not contain the gluten-forming proteins. Unfortunately, no single flour or starch can replicate the properties of wheat flour;^[1]^[2] as a result, high-quality gluten-free baking typically requires a blend of alternative-grain flours, starches, and stabilizers to replace it.^[3]^[4]^[5]

The bulk of wheat flour is starch, so adding refined starches and starch-heavy flours to your blend is a good place to start for bulk and water absorption. However, this still does not provide enough strength to mixtures, and starch-only blends become very unpleasant and rubbery once cooked.^[2] Adding protein helps surround the starch granules, and gluten proteins in wheat flour accomplish this well.^[2] Unfortunately, gluten-free flours typically have less protein than wheat flour,^[2] and the protein they do have does not have the same elastic structural characteristics as gluten.^[2] To compensate for this lack of elasticity and to bind water,^[6]^[7] one or more binders (e.g. gums, fiber) is often added.^[2]^[7]

Selection and storage

Both individual gluten-free flours and mixed blends can be purchased. Some stores sell pre-made "all-purpose" or "cup-for-cup" flour blends^[2]^[4]—these are convenient but will not produce good results in all recipes. They typically work best in certain specific applications (e.g. only in cookies or only in bread, etc) and in recipes specifically designed for them.^[2] When purchasing flours, try to find the most finely-ground ones possible in order to reduce grittiness in the final product.^[8] Additionally, make sure the flours are specifically labeled as gluten-free if contamination is a concern—traces of gluten can sometimes make their way in due to shared processing equipment.

At the minimum, store flours and blends in airtight and moisture-proof containers at cool room temperature.^[1] If the flour is high in fat, storing in the freezer will slow rancidity.

Techniques

Building a blend

There are two main approaches to building gluten-free flour blends. The first is to create one blend for use in multiple recipes. The primary advantage here is convenience, with the idea being that you just have to make a large quantity of one blend and then use it in all your recipes. However, just as there is no single gluten-free flour that can replace wheat flour, there is no single blend that can be used in all recipes.^[8]^[9] Think, for example, of how you cannot just use wheat bread flour instead of cake flour—the end product will be different. To achieve the optimal end result, you will want to figure out the optimal gluten-free blend for a specific recipe.^[1]^[2] Good-quality specialized gluten-free recipes will already have taken this into account for you.

Though you will likely have to tweak a blend, a good starting point if you're building from zero is 60% high-starch components and 40% grain flours, with 15% overall protein content.^[10]^[11] Another guideline is 33% very high-starch component (e.g. glutinous rice, tapioca starch, potato starch), 33% neutral grain flour (e.g. oat, rice, sorghum, millet), and 33% flavorful and often high-protein flour (e.g. buckwheat, teff, nut).^[1] Experiment and adjust with different flours, binders, and other add-ins as necessary.

The following table lists some common components of gluten-free flour blends and their functions in a blend:

Grain flours
Component	Function	Best for...	Substitute with...	Considerations
Rice flour	Neutral flavor; adds bulk; sweet rice flour is high in starch and a good binder^[12]			Can lead to sandy, gritty texture;^[12]^[11] sweet/glutinous rice flour is stretchier and stickier than regular;^[1] brown rice flour has more fiber and protein
Oat flour	Nice balance of starch, fat, and protein; adds viscosity; neutral flavor^[1]^[12]^[13]		Sorghum flour	Needs higher hydration;^[9] not tolerated by everyone with Celiac disease^[11]
Millet flour	Neutral flavor; adds starch and protein^[1]			Excess leads to starchy flavor and mealy texture;^[12]^[9] good in crispy products^[11]
Sorghum flour	Mild flavor; good amount of protein^[12]		Oat flour	>30–50% causes brittleness^[1]
Buckwheat flour	Fiber adds viscosity^[6]			Strong flavor^[11]
Pulse flour	High in protein			Strong flavor^[1]
Teff flour	Adds protein^[12]			Strong flavor, "heavy"^[11]
Starches
Cornstarch	Binds water and thickens; adds crispness and flakiness to pie crust^[1]		Arrowroot starch^[1]	Absorbs less liquid than other starches; can be dry and powdery^[11]
Potato starch	Adds tenderness and moisture; binds^[1]^[2]^[12]			Excess causes heaviness;^[11] best in high-moisture applications like muffins^[12]
Tapioca starch	Adds elasticity and structure^[1]^[2]^[12]			Excess causes high level of chewiness^[11]
Arrowroot starch
Modified tapioca starch (e.g. Expandex)				Good for yeasted breads, improves dough handling
Nut flours
Almond flour	Mild flavor; high in protein and fat;^[12] contributes moisture, structure, and tenderness^[11]			In excess densifies crumb
Chestnut flour				High in starch for a nut flour
Coconut flour	High in fiber and fat;^[9] dry and absorbent^[11]
Binders
Xanthan gum	Binds water; reinforces protein network; thickens^[2]^[11]
Guar gum	Binds water; reinforces protein network; thickens
Powdered psyllium husk	Binds water; reinforces protein network; creates open crumb; improves rise; adds chew and elasticity^[2]^[11]^[14]	Yeasted doughs and pasta^[11]
Flaxseed	Absorbs water and binds^[11]
Chia seed	Absorbs water and binds; adds stretchiness^[1]^[11]
Gelatin	Adds protein; binds water
Pectin	Binds water
Other
Milk powder	Adds protein and sugar; contributes tenderness; helps browning and structure; reduces starchiness^[2]
Egg white powder	Adds protein and structure

Measuring

Because different flours have different textures, densities, etc,^[1]^[2] you are best-off measuring by weight for anything more than teaspoon amounts. Even when not baking gluten-free, weight measurement is more precise and preferred; when baking gluten-free, it becomes a necessity.

Troubleshooting

Working with these blends can require some experimentation and troubleshooting. The following table outlines some considerations:


Issue	Things to try
Final product is too crumbly/brittle/sandy	Increase the proportion of high-starch components^[1] Add/increase binders^[1] Add a bit of acidity^[1]
Gummy texture	Reduce high-starch components and increase protein^[1] Increase neutral grain flours^[1]
Heavy texture and poor rise	Reduce the proportion of protein^[11]
Bread dough/batter is hard to handle	Include a modified starch such as Expandex or Ultratex Add/increase psyllium husk

Use

Gluten-free flours are most commonly used instead of wheat flour in baking recipes. However, in some cases they may be used to provide characteristics that wheat flour does not have (usually flavor). They may also be used in cuisines or recipes that traditionally do not use gluten-containing grains—for example, glutinous rice flour is used to make many traditional foods across East and Southeast Asia.

Substitution

Some gluten-free flour blends market themselves as "cup for cup" or similar. The claim here is that an equal volume of the gluten-free blend can be substituted for the wheat flour in any recipe that contains it. While convenient, this is not actually realistic. When you remove wheat flour from the recipe, so many other factors need to change that just substituting an equal volume of a gluten-free mixture will not cut it.^[8] Additionally, as mentioned, different baked goods have different desired characteristics—no one blend can account for all of these. While you can substitute "cup-for-cup" and get an analogous product, it will not be as good. To see which individual flours can be substituted for each other, see the above table.