Why egg solidify

When you heat the egg you increase the tiny random jiggling motion of the molecules. In any material warmer than absolute zero, the atoms and molecules move around at random. Higher temperature means faster random motion. As the egg heats, the random motion gets fast enough to break the bonds that keep the proteins folded up. So the protein molecules unfold. The kind of weak bonding that once held the protein molecules in a folded position now works in another way.

Here and there, a loose end of one protein molecule comes alongside a loose end of another. The loose ends overlap and bond side-to-side. As the egg gets hotter, the spliced proteins form a mesh with water filing in the spaces within the mesh. As more protein molecules unfold and connect to each other, the mesh gets stronger and the egg becomes more solid. When the mesh is strong enough for your taste, you take the egg off the heat. So, when you cook an egg, the important change is in the arrangement of the protein molecules.

They unfold, connect to each other, and form a mesh that gives the egg its new, solid, cooked consistency.

Want to know more about eggs? If you've ever wondered about whether or not eating the eggs you buy from the grocery store is equivalent to eating a baby chick, we've got a past episode for you to read.

A Moment of Science is a daily audio podcast, public radio program and video series providing the scientific story behind some of life's most perplexing mysteries. This phenomenon is called frozen gelation of eggs.

It becomes a solid when heated between 45 and 75 degree Celsius, and becomes a liquid when cooled again.. In the case of hard-boiled eggs, the proteins clump together and solidify, causing the egg white and yolk to harden. If the protein level drops, it might make it harder to set and stay runny. Drain the hard-boiled eggs and put them in a pot of cold water cooling them in cold water will make the eggs easier to peel.

When you bake a potato, the starch granules absorb the moisture within the potato. Within the confines of the potato skin, moisture soon turns to steam that expands with great force, separating the starch granules and making a fluffy baked potato. When an egg is boiled, the globular proteins albumin of egg white coagulate denature to a rubber like insoluble mass. This insoluble mass absorbs all water present in egg as it makes hydrogen bonds with it. Using too much water will take too long for the water to get boiling, which can throw off the timing and give you overcooked eggs.

Too little water causes parts of the eggs to be exposed and end up under cooked. If you have 2 or 3 layers of eggs stacked up in a small pot, they may cook unevenly. Let the eggs sit in the ice bath for at least 5 minutes.