Popular among the legionaries and proletariat of Rome, this drink had several invigorating side effects, which you can experience in your own kitchen!
A mosaic of a flagon and cup of a beverage, assumed to be wine. Could it actually be posca? From the Bardo National Museum, Tunis.
Roman legionaries were renowned for their physical toughness, often having to march about 20 miles for multiple consecutive days just for training. During war, on top of considerable marching, they needed to carry close to 100 pounds of armor, weapons, and gear. With such energy expenditure, legionaries needed a near-constant supply of food to meet their needs.
Taste wasn’t necessarily a serious concern for the army — what mattered was how well items could travel and keep. Hard cheeses, salted meats, and copious amounts of grains in the form of bread and porridge were essentials as they took longer to spoil than fresh foods like produce, and, what’s more, could be carried in baggage trains wherever the army needed to travel.
Though there was generally ample food for soldiers, the drink situation looked very different. For legionaries (and travelers in the empire, too), water wasn’t always abundant, and even where there were lakes or rivers, the quality was often questionable. Though the concept of microbes was foreign to the Romans, somebody decided to use flavorings to mask stagnant water’s scummy, off-putting flavor. Vinegar was used for this purpose, and, from what I discovered, it had several other favorable side effects.
First, vinegar has natural disinfectant properties due to its acidity, so it would have done a decent job to kill any germs lurking in the water soldiers were looking to drink. Second, vinegar has a very sharp and sour taste, so it probably kept legionaries awake through days of arduous marching. Finally, it ostensibly helped drive away thirst, finding a fan in Cato the Elder, who drank it even after his days in the army. Plutarch describes Cato’s preferences in a section of his work Parallel Lives about the man:
Water was what he drank on his campaigns, except that once in a while, in a raging thirst, he would call for vinegar, or, when his strength was failing, would add a little wine.
This vinegar, when mixed with water, and, by some accounts, spices and honey, makes a drink called posca. In addition to its frequent consumption by soldiers, it was a common drink of the lower classes and slaves, probably a result of its simplicity and easy access to its ingredients.
Despite posca’s apparent popularity among many Romans, few recipes have survived, and even those that have are relatively obscure. I couldn’t find it anywhere, but Aëtius’s Iatrica supposedly offers a recipe or two. Paul of Aegina’s Epitomae Medicae also gives a recipe, which I did manage to uncover, at least partly.
In addition to the meager historical evidence I found, I experimented a bit to create a recipe I found to be palatable. This recipe serves one, but can be doubled or multiplied however to make more:
1 cup of water (preferably from the tap, not from a still pond)
¼ cup + 2 tbsp of red wine vinegar
2 tbsp of honey
Pour all ingredients into a small pot and put on the stove. Heat and stir until the honey is dissolved.
A picture of my ingredients and the final product.
I found that some other posca recreations called for coriander seeds. Those recipes didn’t explain why they chose coriander, so I decided to exclude it. Also, though Paul of Aegina called for ingredients like cumin, anise, and fennel, I couldn’t imagine the average legionary would have free access to spices while on campaign.
When I first tasted the posca I made, I coughed. I definitely wasn’t prepared for the vinegar, but I found that the sharpness quickly went away and I was left with a very mild taste. It didn’t leave a bad aftertaste, which I thought to be pretty surprising considering that other types of vinegar (apple cider especially) aren’t pleasant after drinking them. I quite liked the posca and would certainly make it again.
As it’s sometimes jokingly dubbed “ancient Gatorade,” I can understand why posca was a staple of legionaries across the Roman Empire: it’s easy to make, it’s rejuvenating, and the vinegar probably masks the flavor of foul water (and just about sets your hair alight).