If you slipped back through time to taste a dish from the Roman Empire, you’d likely be sampling some fermented fish sauce.
Surviving Roman recipes add this to anything from barley porridge to a sweet custard made with pine nuts, olive oil, wine, honey and pepper.
Although it is often referred to as garum, the exact meaning of this term is surprisingly uncertain.
A fish sauce by any other name
Fish sauce is called garum, liquamen, or garon (in Greek) in various ancient Roman texts, including labels on containers.
It’s unclear whether these were different products or if the name changed over time.
According to one recent theory, garum may have been an expensive condiment, of short-lived popularity, made with the blood and organs of large fish.
Liquamen was a low-cost cooking sauce popular across the centuries and made by fermenting whole small, cheap fish.
The fish were layered with salt in covered vats or pots, and left in warm sun for two to three months to liquefy and ferment.
The method has been replicated by experimental archaeologists and even instagrammers.
Such umami-flavoured sauce would have transformed the cheap food of ordinary people in the Roman Empire. Most of the population had no access to the expensive spices, meats and sweet raisin wine on the tables of the wealthy.
In an edict listing prices issued by the Emperor Diocletian in 301 CE, second quality fish sauce is half the price of cheap honey.
Containers found in the humble houses and food shops of Pompeii show ordinary people had access to fish sauce.