What do you call the white part of an egg?

The albumen, from the Latin for white, and it is about ninety per cent water with the rest mostly protein. Its job is partly cushioning and partly chemical warfare: it is strongly alkaline and contains enzymes that dissolve bacterial cell walls and proteins that lock up the iron bacteria need to grow.

Whisking it works because those proteins are folded up and can be forced open. Beating unravels them, they link into a network around the air bubbles you are introducing, and a liquid that was mostly water becomes a foam eight times its original volume. A trace of fat - a spot of yolk, a greasy bowl - disrupts the network and it will not rise, which is why the instruction to separate carefully is not fussiness. Copper bowls genuinely help, because copper ions bind one of the proteins and make the foam more stable.

An eggshell is porous, which is how the embryo breathes, and it comes with a natural coating that seals it. Britain does not wash eggs and keeps them at room temperature; the United States washes them, which removes that coating, and must then refrigerate them. Both systems work and neither is compatible with the other, which is why the supermarket egg aisle looks so different depending on which country you are standing in.