Wheat Gluten. 

Bob's Red Mill Vital Wheat Gluten is made from the protein found in the endosperm of the wheat berry, containing 75% to 80% protein. When combined with water it becomes highly elastic and has a taffy-like texture. A small amount added to yeast bread recipes improves the texture and elasticity of the dough, helps retain the gas and steam from baking, and gives more volume to the baked bread. It can be especially helpful for baking breads made with whole grain flours and coarse cereals. Vital wheat gluten is often used by commercial bakeries to produce light textured breads, and can easily put the home bread baker on a par with the professionals.