One of the most frustrating aspects of being gluten-free is the fact that wheat-free flours just don’t behave like their gluten-laden counterparts. A cake made with oat flour often seems to sink, have too high a moisture content, and never truly brown in the same manner a gluten-filled cake would. But why is this? What is it about wheat that gives baked goods a property unachievable by any other grain?
In terms of gluten as an aspect of food science, it is the protein portion of wheat flour with elastic characteristics necessary for the structure of most baked goods (this is why different recipes will call for more or less flour – depending on if you want bread with a lot of structure, or a sauce with just a small amount of added viscosity). Interestingly, from a culinary standpoint, gluten is not present in plain old flour! In order to form gluten from flour, the product must be hydrated (with water or milk) and be manipulated (with stirring, kneading, mixing, or mashing)!
When it comes to gluten-free grains, like uncontaminated oats, rice, and corn, the lack of gluten protein actually inhibits gas retention and the structure building properties that are natural to wheat grain. This prevents our baked goods from having any leavening power, due to a different protein content.