What happens to eggs when they are overcooked?

When eggs are overcooked, they undergo a series of chemical changes that negatively affect their texture and overall quality. The proteins in the egg whites and yolks coagulate, which causes them to firm up. If cooked beyond their optimal point, these proteins continue to bond and tighten, leading to a rubbery, tough texture.

Moreover, the overcooking process can also cause the moisture within the egg to escape, leading to a watery consistency. This occurs because the heat causes the protein structure to contract excessively, forcing out water. Therefore, the outcome is not only a tough texture but also the presence of excess moisture, which is what contributes to the watery appearance. This combination of toughness and moisture loss is characteristic of overcooked eggs, making the choice of a tough and watery result accurate in describing the effect of overcooking eggs.