The famous story says chef George Crum invented the potato chip in Saratoga Springs in 1853 to spite a complaining Cornelius Vanderbilt. This episode explains why that tale is largely a 1973 marketing creation, why Vanderbilt was in Europe at the time, and why the real origin lies in William Kitchener's 1817 London cookbook The Cook's Oracle, which already described frying potato shavings after drying them in a cloth.

From there we follow the engineering problems that turned a fragile fried slice into a $16 billion global industry: Laura Scudder's hand-ironed wax paper bags that beat oxidation, Tayto's 1954 breakthrough in making seasoning stick, the shift from batch kettles to continuous fryers, Cape Cod's return to kettle cooking, and Pringles' extruded saddle-shaped crisps that the FDA will not call chips.

• Why chips sold loose ...