Breakfast cereal’s far from plain story

Corn flakes may seem the most straightforward of breakfast choices, yet their story is anything but plain.

At their simplest, they are toasted, flattened flakes of milled maize, usually fortified with vitamins and minerals, lightly sweetened, and designed to stay just crisp enough in milk to give a brief crunch before surrendering.

The process of making them looks unromantic on a factory floor, but it represented a minor technological triumph of the early 20th century, when...