The word "gluten" is bandied about these days in much the same way the word "communist" was back in the 1950s; only instead of the Red Menace, today it's more like the Bread Menace.
To be sure, around one percent of the population (1 in 100 people) suffer from an autoimmune disorder called celiac disease, in which the consumption of gluten causes damage to the intestines. This, in turn, prevents the normal absorption of nutrients, leading to malnutrition. It's a serious condition, and celiac sufferers need to be careful to avoid gluten.
But what exactly is gluten, and how does it figure into the culinary arts?
What Is Gluten?
Gluten is a combination of the natural proteins found in wheat, and to a much lesser extent, in rye and barley. Gluten molecules are activated when flour is moistened then either kneaded or mixed. When this happens, the glutens literally stretch out as the proteins form longer and longer chains.
These long protein chains are quite elastic, which is why you can stretch out a piece of dough without it breaking or tearing. It's similar to a balloon.
This elastic property of gluten then works with the gases produced by yeast or another leavening agent. The gases inflate these gluten balloons, which is what causes doughs to rise. Finally, when it's baked, the dough hardens in its inflated state, giving the bread its structure.
Flours Containing the Most Gluten
There are different varieties of wheat, each with its own gluten content. Flours made from high-gluten wheat are called strong flours and are used for making bread, bagels, pasta, and pizza crusts. Flours made from softer, low-gluten wheat are called weak flours and are used for making cakes and delicate pastries.
All-purpose flour is formulated to have a medium gluten content of around 12 percent or so. This makes it a good middle-of-the-road flour that can be used for a whole range of baking.
Role in Baking
Without gluten, baked goods won't hold their shape. That's why wheat flour is used in baking. When the glutens in wheat are stretched out through the kneading or mixing process, they form little pockets which can then be inflated by the gases released by the leavening agent. When these air pockets inflate, the dough expands or rises.
And since gluten is a protein, it hardens when it is heated—just like the protein in an egg hardens when we cook it. This hardening of the gluten molecules is what allows the bread to hold its shape and gives it its firm texture.
The more the dough is mixed or kneaded, the more the glutens develop. That's why we mix the dough for cakes or pastries for a shorter time than for crusty French rolls.
Interaction With Fat
In baking, fats interfere with gluten development process. Cookies are more crumbly than bread because they've got more fat in them. What happens is that the fat molecules surround and literally shorten the strands of gluten so that they can't stretch out as much. That's where we get the name "shortening" as well as shortbread cookies.
Gluten and Pasta
Gluten is also a key component in foods that aren't baked, like pasta. The gluten is what gives the pasta its firm texture. Strong flours such as those made from durum wheat are good for making pasta because of their high gluten content. Pasta made from low-gluten flour would be too soft and mushy.
Is it Possible to Bake Without Gluten?
Gluten provides structure and chewiness, but it's also the only way to create light, airy baked goods. That's because, without gluten, bread won't rise. This is why, if you've ever tried gluten-free bread, they're so heavy and dense. They're really just lumps of starch.
That doesn't mean that grains that have little or no gluten aren't used in baking. It's just that they need a little help—in the form of wheat flour. Rye bread typically contains more wheat flour than rye flour. Corn also lacks gluten, which is why cornbread is made from about half cornmeal, half wheat flour.