Everything You Ever Wanted to Know About Garum

Extremely tasty and frequently misunderstood, garum is a fermented fish sauce that traces its origins back to Roman times. Over the course of more than a dozen centuries, it has managed to sustain its influence in the culinary world, even if its preparation method may have changed: Unlike the Romans, today’s garum makers don’t typically use huge quantities of fish and salt and seawater to prepare it, much less stone tanks. While the designation “garum” has been used (often incorrectly) to define fish sauces obtained from fermentation without salt, true garum is as relevant as ever, beloved by chefs throughout the world for its robust, umami-rich flavors: With just a few drops of it, you get a whole new dish.

So what is garum, exactly?

Pliny the Elder was one of the first to define garum — which he called an “exquisite liquid” — as “a choice liquor consisting of the guts of fish and the other parts that would otherwise be considered refuse.” Today, fermentation guru Sandor Katz describes it as “a classical Roman name for fermented fish sauce,” one that is “quite similar to contemporary Southeast Asian fish sauces, only typically using less salt, resulting in an even funkier flavor.” Colatura di Alici, a light amber liquid made from fermented, salted anchovies that is still produced on the Amalfi Coast, is considered a direct heir of garum, whose popularity and mass production significantly declined with the fall of the Roman empire.

How is garum made?

A popular condiment in ancient Rome — it has been called the ketchup of the Roman world — garum was originally made with small fish like sardines and mackerel, along with brine and plenty of time. As people began making garum in different regions of the world, aromatic herbs, spices, and even wine were added to the formula.

Before we get into garum’s traditional preparation method — and how it influenced more contemporary ones — it is worth mentioning that ancient fish sauces can be a little tricky. Since garum has meant different things at different times, some historical context is in order.

There is much confusion and contradiction among modern scholars (archaeologists, nutritionists, ichthyologists) about the use of the term “garum” — something that has only become more complex as modern chefs have attached it to all kinds of fermented sauces that they develop in their restaurants, using ingredients as varied as oysters, vegetables, and even egg whites.

The source of the confusion can itself be traced back to ancient Rome. Along with garum, which has origins in Greek and Phoenician cooking, the Romans made liquamen, a different kind of fish sauce. Liquamen “functioned both as a general salt seasoning in cooking and as an ingredient [in] compound dressings that were served as dips and also poured over cooked meat, fish, and prepared dishes,” food historian Sally Grainger explains in The Story of Garum, a book that many experts consider the subject’s bible. According to Grainger, an authority on ancient Roman food whose work has involved analyzing and experimentally recreating the fish sauces of Roman cuisine, garum’s use as a cooking ingredient was comparatively limited.

Making garum was an odiferous task ascribed to Roman slaves and laborers. They gutted small fish, then threw everything — guts, bones, and all — into stone tanks or large clay pots called amphorae, and covered them with brine made by combining different amounts of salt and seawater. The ensuing fermentation process, which could take almost a year, relied on the sun to make bacteria from the fish’s guts break down its flesh, turning it into a thick liquid. The Latin word “garum” referred specifically to a pre-fermented sauce of blood and viscera, Grainger explains in her book, “rather than a general term” for fermented fish sauce.

It is the process of chemical decomposition that allows garum to develop its complex flavor. As the fish’s intestinal bacteria spread through its body, they initiate the fermentation process, which in turn transforms the fish proteins into amino acids like glutamic acid and glutamate, giving the garum its robust umami taste.

How was garum used in the kitchen?

“It is very difficult to determine precisely how it was used,” Grainger writes. “There are hints that garum was a table sauce that was poured onto food, its black glossy appearance will have made it particularly visible to elite consumers.”

Throughout Roman times, garum was sold at different grades and prices, depending on the fish used and the concentration of the liquid — the thinner the better, and more expensive. Weaker versions of the sauce went to more modest kitchens and the Roman army. It was used as a flavoring agent for pork, fish, and even wine, and also combined with ingredients such as pepper, vinegar, and oil to create new compound condiments. And because it was made from fish, it was also considered a source of protein. Over time, garum became so essential to the ancient Roman palate that a network of trade routes was established from different places such as the Iberian Peninsula, Mediterranean Sea, and North Africa, where large-scale production sites were built to supply the Roman craving for liters and liters of the smelly relish.

How are modern chefs recreating garum?

Sandor Katz explains that many contemporary chefs use the name garum to describe sauces made from fermenting seafood, animals, insects, or even vegetables with salt and koji, the Japanese name for grains inoculated with the fungus Aspergillus oryzae. “These can be wonderfully delicious, but are a departure from the traditional garum,” Katz points out.

At the fermentation lab at René Redzepi’s Copenhagen restaurant Noma, koji is one of the ingredients used to create different versions of garum. They are brewed in a warm solution of koji rice. “When we first started exploring those traditional processes, we realized that there was an opportunity for us to use other ingredients to produce powerful flavors as well,” explains Jason White, the restaurant’s director of fermentation.

Since at least 2014, Noma’s fermentation team has created garum from ingredients as disparate as beef, chicken wings, various vegetables, smoked mushrooms, and egg whites. “We were incredibly fascinated,” White says, “with how replacing meat with vegetables could give us different and interesting sauces.”

Along with its ability to break down proteins into free amino acids (which create umami flavor), koji also helped to create sauces that were powerful but still delicate. “We found out that by not using guts and the blood [like the Romans did], we could focus more on the flesh, which gave us cleaner flavors, so we started naturally using koji instead of the natural enzymes found in the meat,” White says. Another advantage of koji is that it yields less salty garums, “Flavorwise,” he adds, “you get more from the ingredients and not just salt, which also makes garum an incredibly versatile product.”

Many other restaurants make garum from a combination of protein, water, salt, and koji. “The koji is the biggest variable, not just if it’s rice, barley, or another grain, but the way that we grow it or drag it out of the [fermentation] process,” explains Trey Smith, the co-chef and co-owner of the New Orleans restaurant Saint-Germain. “The process changed from batch to batch as we made adjustments, tasted the difference, and recorded input and output along the way”.

So what do chefs look for in a garum?

Smith searches for umami-rich sauces that reflect the flavor of what he’s seasoning at the restaurant. “For example, we’ll season roasted lamb with a lamb garum or we’ll poach lobster in a lobster garum butter to amplify the natural flavor,” he explains. “Lamb garum should taste almost like a roasted lamb extract. Fish sauce and soy sauce can add umami to a dish, but sometimes it changes the overall flavor profile in a way you don’t want. Seasoning a steak with beef garum just makes it taste even more like beef.” The beef garum, Smith adds, is made with “koji that we’ve grown a little slower than the one we use for other garums. It results in a sauce that’s nutty, bitter, sweet, and tastes ‘roasted.’”

What are some of the other ways chefs are using garum?

The applications of garum are as vast as its flavors: Restaurants have been using it in soups, sauces, meat, and even cocktails. Pere Planagumà, the chef of Les Cols in Girona, Spain, turns Cantabrian anchovies into his own brand of garum, called Escata, that he recommends using with rice, pasta, cheese, potato chips, and various desserts.

Dessert is also the destination for the garum that Josh Niland, the chef of the Sydney restaurant Saint Peter, makes from the heads, bones, and scraps of small fish like sardines and mackerel; he uses it to flavor the caramel he puts in tarts and other sweet dishes.

Elsewhere, chefs use garum to finish a variety of dishes and as a base for sauces and condiments that bring out the flavor of grilled meats and raw vegetables alike.

If you’re not a chef, where can you buy garum, and how can you use it?

Thanks to specialty stores and Amazon, it’s possible to buy garum from all over the world. Zingerman’s, for example, sells a garum colatura anchovy sauce imported from Italy. From Andalusia, Spain — an important former site for garum production — Matiz’s Flor de Garum is a premium sauce made only using anchovies, salt, and spices (from oregano to black pepper). You can also find Pere Planagumà’s Escata garum, which is made with Cantabrian anchovies, online. And Noma Projects’ smoked mushroom and egg white garums are set to be released online sometime this winter. Once you get your hands on some garum, start experimenting with it. While it’s good to start slow, using only a few drops at a time, just remember: The world is your fermented anchovy.

Rafael Tonon is a journalist and food writer living between Brazil and Portugal. Sophia Pappas is a Pittsburgh-based illustrator.