UNDERSTANDING GLUTEN
Gluten is simply a term for the specific proteins (glutenins and gliadins) found in wheat. All proteins are comprised of chains of amino acids. In dry form, wheat proteins have little to no structure. When combined with water, these gluten proteins change shape, form bonds with one another, and produce tightly coiled, yet highly elastic structures.
These protein structures have the ability to stretch to a large degree. The proteins can stretch and expand, yet inherently provide structure and shape. This unique stretching characteristic of gluten allows us to create airy bread and pastries that hold their shape and crispy puffs and samosas.
Very important note: While whole wheat flours do contain high quantities of protein and gluten, they generally produce weaker gluten strands (due to the presence of the bran and germ in the flour). Strong gluten strands allow for expansion and air. Weak gluten strands make this more difficult. This is why most bakeries use only maida or all purpose flour for baking.
As you add more water to gluten, you produce more concentrated gluten. When this mixture is worked, stretched, or kneaded, the proteins stretch and become even more elastic. The less the mixture is worked, the less concentrated the gluten will be. Some types of baking benefit from the development of gluten (ie. bread or pizza doughs, pasta, puff pastry, etc.) and certain types of baking do not (ie. pancakes, baking powder/baking soda leavened batters, pie dough, cakes).