Gluten is the one (ok, two – but we’ll get to that) protein that rules the world of baking – it gives bread its structure and signature texture, and the amount of gluten present in flour is one of the most important differences between different types of flour. But how does gluten work, and how do we know how to use it to get that handshake-worthy bake?
Well, gluten is simpler than it seems. What we call “gluten percentage” in flour is actually the protein percentage, specifically the proteins gliadin and glutenin – when these proteins mix with water they create gluten. However, the reason why gluten is so important, and why gluten-free foods just aren’t the same, is that gluten is made up of many chain-like molecules that can form an elastic network that traps air and CO2. This is what gives bread and cakes their signature airy texture and what gives bread its structure.
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Credit: Schopf et al, CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons
How do we Use Gluten Better?
But knowing the science behind gluten isn’t enough to use gluten more efficiently in practice – we need to understand how to use the science to adapt recipes when things don’t work according to plan. One of the most important parts of gluten development, especially in bread, is kneading. To create the “elastic network” we talked about previously you must knead the dough to incorporate air into it. This air will expand in the oven as it heats up causing the open texture that we want in bread. As you can see below, this step is essential as it creates elastic networks of stretched gluten strands that, when baked, will create an incredible loaf of bread.
Credit: General Views, CC BY 2.0 https://creativecommons.org/licenses/by/2.0, via Wikimedia Commons
Another very important step for creating light, airy bread is proofing, when proofing yeasted bread, the yeast releases carbon dioxide into the bread, creating more air bubbles and expanding the already present air pockets. Both of these processes are essential for getting the texture that you want in a bread, so if your bread doesn’t have the texture you want, these two techniques should be one of the first two places you look.
Once those techniques are done correctly, there are many other ways to change the texture of bread, such as adding salt for chewier bread and a more elastic dough. This works because as you might know, salt draws moisture out of food. When the water drains out of the dough the protein molecules become closer together, leading to a chewier bread. For the opposite effect, you can add fats, like butter to “shorten” the dough. Fats are usually added to flour before wet ingredients like water or milk are added. This allows the fats to coat the flour, stopping the water from mixing with the gluten, and creating a less developed gluten network. This process shortens the gluten strands leading to a softer baked good.
Once the processes of kneading and proofing are mastered, there are many different ways to improve your dough. When trying to change the texture
What Type of Flour Should I Use?
Now that we know how to develop the gluten in flour, we need to understand what type of flour to use. If you have ever been to the baking aisle of a store, you have probably seen many different types of flour, like bread flour, all-purpose flour, whole wheat flour, and possibly even more, but what do they all mean? Well, the main thing you need to know about these different flour types is that they usually contain different amounts of protein and therefore, different amounts of gluten. But to truly understand when to use what flour we need to look closer.
All-Purpose Flour: This is the most common and versatile type of flour and most likely the flour you have in your kitchen. All-purpose flour has a protein content of ~11-12%, making it usable in most recipes that call for flour, but best for cookies, muffins, quick breads, and pie crusts. All-purpose flour is also usually used for cakes, but if you are looking for an especially light and soft cake you may want to try cake flour. Similarly, all-purpose flour can be used in many breads, but for bread, if you can get it, bread flour is a much better choice as the extra gluten in bread flour creates much better airier bread.
Credit: “Sandwich Bread” by Cooking from Heart, licensed under Creative Commons. Retrieved from Cooking from Heart.
Bread Flour: As we learned earlier, bread flour is a higher gluten flour, with a protein content of 13-14%, it is perfect for bread, hence the name. The higher protein content of bread flour creates a better structure due to a more developed gluten network. This more developed gluten network also allows for more airy yeasted bread, as it can trap more CO2 produced by the yeast.
Credit: Angel Ganev, CC BY 2.0 https://creativecommons.org/licenses/by/2.0, via Wikimedia Commons
Whole Wheat Flour: Whole wheat flour, usually used for its health benefits instead of being better for specific foods, is made by grinding the entire wheat berry, including the inner germ and the outer bran, giving it more nutritional value. While grinding the entire wheat berry does create a higher protein content of ~14%, this does not create better bread as the bran in whole wheat flour has sharp edges that cut the strands of gluten as they form, stopping a fully developed gluten network from forming. This creates a loaf of bread that can be dense and tough. However, when creating sandwich bread, this amount of air is not required and therefore whole wheat can be a great choice for those who are health conscious. Along with sandwich bread, you can also consider switching out 25% of the flour in non-bread baked goods for a healthier product.
Cake Flour: Cake Flour is the opposite of bread flour, with its main trait being its lower protein content of ~10%. The lower gluten content allows for a softer, more tender cake. While cake flour is much less commonly used than bread, flour, if you are having trouble getting the consistency you want in your cakes, you may want to consider trying cake flour. This doesn’t only work for cakes though. For example, if you prefer cakey, soft cookies, you can try switching out the all-purpose flour for cake flour.
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Self-Rising Flour: Unlike most other types of flour, self-rising flour’s main quality is not its protein content but the addition of baking powder and salt for convenience. While the protein content is not the main focus, keep in mind it has a relatively low gluten content of ~9%. This makes it less ideal for baked goods like bread, but great for especially light biscuits, scones, and pancakes.
So there it is: the secrets of gluten, the science and the theory. In my next post, I’ll show you a little more about how to put this into practice with a deep dive into baking ciabatta bread.