When you substitute wheat flour with gluten-free flour, you are not just changing the flavors of a recipe, because wheat flour contain gluten and gluten-free flour doesnt contain gluten. Gluten is a protein found in wheat that provide structure to baked goods, and gluten acts as a binder that holds ingredient together. If you remove the wheat flour, you are also removing the gluten, and because you are removing the gluten, you are also removing the structural integrity of the baked goods.
Therefore, a person cant simply replace wheat flour with a single type of gluten-free flour and expect the same result, because a single substitute doesnt provide the same mechanical property that gluten provides. Different types of gluten-free flour behaves differently when you use them in a recipe, and you must understand these differences to achieve the correct texture. For example, coconut flour is a gluten-free flour that absorbs a large amount of moisture, so if you use coconut flour without adding extra egg or extra liquids, the coconut flour will make the baked good dryly and fibrous.
How to Bake with Gluten-Free Flour
Many people attempt to use a single gluten-free flour for every recipe, but using a single gluten-free flour often lead to poor texture. Instead, you should use a blend of different flours, because a blend of flours allow you to balance the nutrition and the texture. For instance, you can combine a base grain, such as rice flour, with a starch, such as tapioca starch or potato starch.
The rice flour provides the bulk of the baked good, but the starch provide the lightness and the stretch that mimics the effect of gluten. Texture is a primary concern when you use gluten-free flour, and you must match the gluten-free flour to the specific goal of the recipe. If you want to make a soft pancake, you might use oat flour because oat flour create a gentle crumb.
If you want to make a pliable tortilla, you might use cassava flour or arrowroot flour because cassava flour and arrowroot flour offer a more elastic quality. You should not use a heavy flour, such as almond flour, to make a delicate sponge cake, because the density of the almond flour will change the density of the cake. Because gluten-free flour doesnt have gluten to hold air bubble in place, you often need to add a binder to the recipe.
Xanthan gum is a common binder that act as a substitute for the elasticity of wheat. If you use too much xanthan gum, the baked good will feel gummy, but if you use too little xanthan gum, the baked good will crumble. Additionally, you must monitor the temperature of your oven because gluten-free flours, especially nut based flours, brown faster than wheat flour.
If you use a high temperature, the outside of the baked good may brown before the inside is fully cooked, so you should consider lowering the temperature and increasing the baking time. Finally, you must store your gluten-free flour correctly and prepare your batter proper to ensure success. Nut based flours, such as almond flour and coconut flour, can go rancid if you store the nut-based flours in a warm pantry, so you should keep the nut-based flours in the refrigerator to preserve the taste.
You should also let your batter rest for several minute before you put the batter into the oven, because letting the batter rest allow the grains to hydrate. If the grains do not hydrate, the baked good may have a gritty texture, but if the grains hydrate, the texture will be more smoother.