The Science of Gluten
When flour and water combine in a dough or batter they work together to create the chewy, bouncy structure we all love in breads and baked goods. It may seem like magic but it’s actually science—read on to learn more.
Gluten Strands - Starch Molecules
Flour is milled from wheat berries, which contain starches, proteins, and fats. There are two main proteins in wheat flour—glutenin and gliadin. Glutenin is a very large, loosely coiled protein, while gliadin is a much smaller and tightly coiled sphere. Glutenin provides most of the strength and elasticity in dough, allowing it to bounce back after it has been stretched. Gliadin, on the other hand, provides the stretch.
Water
In dry flour, these proteins are basically lifeless strands wrapped around granules of starch. But they begin to change shape when they come in contact with water, a process called hydration. Once moistened, the individual protein molecules (the glutenin and gliadin) begin to link up with one another to form long, elastic chains called gluten. These strands of gluten combine to form a membrane-like network. The network engulfs swollen starch granules and gas bubbles (created by yeast, chemical leaveners like baking powder, or foams like whipped egg whites), stretching as the batter or dough rises and then bakes, giving the finished cake or loaf its structure and chew.
