Gluten, a combination of proteins in wheat flour, absorbs liquid to form elastic strands that capture steam and the carbon dioxide created by the yeast, helping baked goods to rise. It also makes baked products chewier. High gluten flour contains more protein than most other wheat flours.

High gluten flour, made from hard spring wheat, averages 13 to 14.5 percent protein by weight, compared with 10 to 11 percent for all-purpose flour. Commercial bakeries use high-gluten flour to create chewy baked goods such as hearty artisan breads, pizza crusts and bagels. They also combine it with lower gluten flours to make products such as rye bread lighter.

Because most home bakers don’t use flour specifically designated as high gluten flour, you’ll rarely find it in a regular grocery store. You can special-order it from some stores that sell baking ingredients. Or just use bread flour, which is widely available. It is made from hard, high-protein wheat, too, and has a protein content that averages 12 to 13 percent.