Rome’s Ketchup: Garum, the Fermented Fish Sauce
The best-selling Roman condiment was made from rotting fish guts.

Salvator Rosa — "The Dream of Aeneas" (1660–65), public domain
Fermentation on an Epic Scale
From Spain to Sicily, entire Roman towns stank of garum—fish offal salted and left to rot under the sun. The resulting liquid packed a savory punch that Roman cooks splashed on nearly every dish.
A Commodity Worth Its Smell
Garum was big business. Archaeologists have found stamped amphorae and factory ruins along Mediterranean coasts. Some varieties sold for eye-watering prices—others, only the poorest could endure.
Garum, a salty, fermented fish sauce, flavored everything from bread to desserts. Factories churned out thousands of amphorae, making the stench—and the export profits—impossible to ignore.