Ancient Romans had yummy condiments. Here’s a recipe.

We’ve all become used to recipe videos for chocolate-dipped ice cream balls and assorted cheese-drenched confections. But ancient Romans had a surprisingly common recipe of their own. They used it more frequently than salt, and they manufactured it across the Roman Empire.

The recipe varied as well — we’ve included a variety of fish options, though the video above only uses the widely praised mackerel innards.

People had many ways of making garum, which makes it tough to know exactly what most Romans ate but easy for you to make a similar fish sauce at home.

It was so popular that poets wrote about it, though not uncritically: Martial said that for young Romans on the prowl, dating someone who’d recently eaten garum was a frightening proposition. While garum is similar to modern fish sauces, most taste testers report that its flavor is surprisingly subtle, teasing out the umami in seasoned foods.

As is common in tracking down ancient customs,what counts as “garum” requires using the best available information to make an educated guess. But these recipes might give you an idea of what this popular ancient Roman sauce tasted like. Once you’re done, try adding your garum to these recipes from Patrick Faas’s book of ancient Roman recipes.

Author Laura Kelly took nine months to make authentic garum, but that’s a little longer than most ancient sources recommend. To make a modified recipe, you can take less time, but you should use fermented mackerel. (Sources vary on whether to use the entire mackerel or its intestines.) Researcher Robert Curtis also provides another, more thorough recipe.

Quantities should be adjusted to suit your needs, since what we can find from old mackerel recipes probably calls for much more garum than you need.

Ingredients

Instructions

Prepare the mackerel, using the whole fish or, preferably, only the blood and intestines. Mix it with sea salt — the best recipe with a ratio, from a 10th-century compilation called the Geoponica, recommends about one part salt for every eight parts fish. Dried herbs are optional.

Let the mixture ferment in the hot sun for two months. (Time varies by author, but one to six months is common, though as little as 20 days might suffice.) Stir to help dissolve the mixture and then strain the liquid from the top. Ideal coloration is clear, but your garum’s color may vary.

Most modified garum recipes recommend boiling fish and water and straining the resulting mixture. (Of course, these modified garum recipes result in a different and less subtle taste than the “classic garum.”)

Instructions

Boil the sea salt and fish in water until the mixture thickens, crushing the fish as necessary. Five minutes before finishing, add grape juice or oregano. Strain the mixture and bottle.

Nova has a great list of Roman recipes, and its “modern garum recipe” is simple: It recommends cooking a quart of grape juice and then dissolving 2 tablespoons of anchovy paste in the juice, along with a little oregano.

Of course, you can always cheat — which isn’t the worst thing, since many of our garum recipes involve some guesswork at ancient methods.

Many Thai and Vietnamese fish sauces are very similar to garum, as is this colatura anchovy sauce, which may not be made that differently from ancient garum.