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Gluten has been feared and revered, misunderstood and maligned. It's the backbone of almost any type of baking, and yet… many bakers are also confused by it.
It's hard to talk about gluten without getting into food science, so it can be a confusing topic. But if you have a basic understanding of what gluten is and how it works, that knowledge will take you (and your baking) a long way.
So what exactly IS gluten?
A common misconception is that gluten is part of flour. Technically, this is not true. Gluten is ESTABLISHED from flour when water is added. That bag all purpose flour sitting on the counter contains two proteins needed to form gluten: glutenin and gliadin. When water (or a liquid that includes water, such as milk) is added to these two proteins, they bind together, forming gluten.
So instead of thinking about how much gluten a particular flour contains, it's more accurate to think about how much gluten-forming protein the flour contains.
What does the protein content of flour mean? Is it gluten related?
You'll find protein content printed on bags of King Arthur flour, from cake flour to all-purpose bread flour. The higher the protein content, the more gluten-forming protein a particular type of flour contains. One way to think about it: the higher the protein, the “stronger” the flour.
Cake flour, with a protein percentage of 10%, has low gluten development potential. When you mix batter made with cake flour rather than all-purpose flour, there is less protein; as a result, the dough will develop less gluten.
Bread flourOn the other hand, it has a protein percentage of 12.7%. Because there is more protein present, the dough is able to develop more gluten. This means that dough made with bread flour will be stronger than one made with cake flour or even all-purpose flour if all are given the same amount of kneading or stirring.
All purpose flourmeanwhile, it has a protein percentage comfortably in the middle of this range at 11.7%, so it's suitable for most baking projects, from cakes to bread.
An important note about whole grain flours: The total protein content of whole wheat flour is 13.8%, but because whole wheat flour contains all parts of the wheat grain, including the bran and germ, the gluten structure is affected. This is because the bran has sharp edges when ground, which cut some of the gluten fibers and interfere with their structure. (You can read more in our post at choosing the right flour (how this leads to shorter, denser bread.)
In that case, how does gluten develop?
When liquid is added to glutenin and gliadin, they begin to form bonds that bind together, developing gluten strands.
As you mix and cook doughs and batters, you encourage the gluten to develop further. This is because this movement and agitation encourages the gluten strands to bond and form a network, which makes them even stronger.
Remember how there are two different types of protein in flour? Each one does something a little different to the dough as the gluten develops. Glutenin gives the dough elasticity (so it can snap like a rubber band), while gliadin contributes to stretch (meaning the dough can stretch).
How does gluten affect baking?
Depending on the type of baking you are doing, you may want a lot of gluten development or as little as possible.
You know that network of gluten strands we talked about that forms when dough or dough is kneaded? This mesh is able to trap gas bubbles; the firmer it is, the more gas it can hold, leading to more air in the baked goods and thus a higher rise. At the same time, those interconnected strands become longer and stronger as the gluten develops, which leads to more chewiness and consistency in the final product.
For bread, you want plenty of dough strength to create chewiness and gas entrapment as the dough rises, while for cakes and other soft baked goods, you want a delicate texture. To achieve each of these goals, you need to control the rate at which gluten develops.
Gluten in bread
According to Ellen King, author of Heritage baking, “Proper gluten development is important for elasticity, how your bread will ultimately rise, and how your bread will hold up once it's formed.” This is achieved by first adding liquid to the flour, starting the process of gluten formation, then cooking or folding the dough to form long, strong interconnected strands.
Sometimes, this agitation is not required: In bread without doughgluten development is achieved with hydration and rest, proving you don't always need to cook.
You can tell that your gluten has developed properly when it comes time to form your dough. “If it holds its shape well,” says Ellen, “you know you're going to be fine.” She explains that under-risen dough will be weak, while over-risen dough will rise too much. One way to make sure you hit the right sweet spot is to follow the visual cues for your dough mentioned in a bread recipe and err on the side of over-doughing rather than under-doughing. (It is extremely difficult to overcook.)
Gluten in cake and other soft baked goods
For any baked goods that are soft and delicate, you want to develop the gluten as little as possible so that a strong gluten matrix doesn't interfere with the structure. Let's use cake as an example.
“Unlike bread, where you want to work the gluten to give it texture … with cake you want a really soft crumb,” says Odette Williams, author of Simple cake. As a result, you have to be careful when mixing the flour into the cake batter to avoid over-mixing it and promoting the formation of gluten strands. Use a light touch and gentle movements when mixing, or the lowest setting of an electric mixer. (But don't worry—if you have a heavy hand while mixing, “You'll still get a perfect cake,” assures Odette.)
Gluten in pastries
If your goal is to maximize gluten development in bread and minimize gluten development in cakes, then pastry falls somewhere in between.
If you are done puff pastry, for example, you need to partially develop the gluten so that it is stretchy enough to roll and fold without breaking. At the same time, it can't be too developed or you won't be able to distribute it well, explains Maggie Perry, a member of King Arthur. Baker's hotline.
Think about pie crust also. You don't want to add too much water or overwork the dough or it will become tough and chewy from over developing the gluten. Maggie explains that rolling and stretching the pie crust provides just enough agitation to develop a firm, flaky crust without becoming tough.
That was a lot. Can you summarize it for me?
Here's what you need to know: When you add liquid to flour, gluten begins to form. Additional agitation—such as stirring, folding, or mixing—continues to develop that gluten, making the protein bonds stronger.
How strong that gluten becomes affects your baked goods. For bread and other baked goods with a chewy texture, you want to encourage full gluten development. This includes using a high-protein flour such as bread flour for more gluten potential. For a soft cake-like baked treat, you want to avoid over-developing gluten, so avoid over-mixing your batter and use a low-protein flour such as all-purpose flour. cake flour.
But really, Odette has the biggest advantage of all. She reminds bakers not to stress too much about getting the gluten right, because after all, “A bad cake is still a good cake.”
Learn more about how your choice of flour affects your baking in our previous post, How to choose the right flour.
Cover photo by John Sherman.
