Adding Shine to the Surface of Baked Goods

A small amount of salt added to an egg wash thins it out. It takes a few hours for this to happen, but it does make the egg wash easier to apply evenly. The egg thins out because the egg proteins are neutralized by the salt and are no longer attracted to one another. This allows the proteins to be better hydrated by water, even to dissolve in it. Biochemists have a term for the ability of salt to dissolve proteins in water. They call it the salting in effect.