For years, you’ve had a taste for something yet didn’t know its name.

It’s umami. Some call it “the fifth taste” after the well-known quartet of the tastes bitter, sweet, salt, and sour. Umami is that very pleasant, savory, juicy, salivary taste set off by certain foods such as a nugget of Parmigiano-Reggiano or a sip of miso soup.

Umami was isolated as a taste and the word coined back in the early 1900s by Kikunae Ikeda, a Japanese chemist. He found that umami stimulated taste buds that were distinct from those stimulated by the other four tastes. (The buds turned out, after further science, to be the palate’s T1R1/T1R3, mGluR1 and mGluR4 buds, but you knew that.)

Ikeda named the taste “umami” after umai, the Japanese word for “deliciousness.” He discovered umami by examining the molecular structure of a staple of Japanese cooking called dashi, a rich broth based in boiled kelp fronds.

Umami isn’t a new taste, just a newly discovered one. It’s been around for millennia, anytime one of the more prevalent amino acids, glutamic acid, is broken down in a food or by our body into glutamate, the acid’s salt. Take a food and cook it, ferment it, or ripen or age it, and the process likely produces glutamate. And glutamate makes umami.

For example, raw meat isn’t very umami. But cure it into a sausage with salt and time and it’s ur-umami. A soybean has a bit of umami; soy sauce is awash in it. Milk, some. Aged cheese? Boom.

David DelCourt, founder of Boulder’s Seed Ranch Flavor Co., designs flavorings and sauces both named after umami and loaded with it. “Everything we do is plant-based,” says DelCourt, “so we said, ‘Where are all those plant-based sources of umami?’ Let’s isolate them for the kitchen.”

So, several of the ingredients in Seed Ranch Flavor’s hot sauces (for example, the company’s Umami Reserve hot sauce) are tamari, tomato paste, dried mushrooms, seaweed, balsamic vinegar, and red miso—all major umami triggers.

You may now splash umami onto dinner, along with some very Coloradan chile heat.

In crystalline form, glutamate is monosodium glutamate — MSG — still available at Asian grocery stores so labeled. (In non-Asian groceries, it’s pretty much all that’s in the red tube of Accent.) But note that many prepared foods contain glutamate as MSG by other names. Look for these names or phrases: hydrolyzed plant protein, textured protein, autolyzed yeast extract, sodium caseinate, and several other food additives.

None are harmful, of course, but they are manufactured turns on glutamate; “natural” in one sense of the word, yes, but also extracted, then added to prepared or processed foods for their intended effect. As with any food, it merely helps to know what it is, that it’s there, and in what quantity.

Other interesting facts about glutamate: our own bodies produce about 40-50 grams of it a day; human breast milk is 10 times as rich in glutamate (and umami) as cow’s milk which may explain evolution’s way to kick-start an infant’s healthy life; and umami-rich foods have been shown not only to assist eaters to reduce their overall sodium intake, but also to stimulate sensory appreciation in people whose taste and smell sensitivity is impaired by either age or medication. (Perhaps it would be salutary for those affected by loss of taste from infection by COVID-19.)

If you are after umami for your own plate, reach no further than dozens of foods: all aged cheeses, fresh and dried tomatoes, tomato juice (even low-sodium sorts), all cured meats, grilled steaks, mushrooms (especially dried mushrooms), leafy greens, preserved or pickled vegetables (such as sauerkraut or kimchi), all the fish sauces, ketchup, Worcestershire sauce, any long-cooked stew or broth, most shellfish, grape juice and its fermented friend, wine, and, if you fancy foods British or colonial, the yeast extract spreads called Marmite and Vegemite.

The list is by no means exhaustive but does illustrate the ubiquity of glutamate and umami in our diet. In fact, were it not for umami, ketchup (given its ingredients, a paste of concentrated glutamate), wouldn’t be as powerful a condiment as it is.

Today’s recipe is an ancient one with its feet in Imperial Rome. For centuries, Romans have flavored their roast lamb—pieces of shoulder meat, legs, shanks—with garlic, herbs, and anchovy, either directly, as in this recipe, with crushed filets, or, in days much gone by, with the ubiquitous Roman flavoring, liquamen (also called “garum,” a thick fish sauce from salted and fermented small fish). Liquamen was chockablock umami.

Do not be so provincial to turn up your nose at the idea of using small oily fish in a roast lamb preparation. They are the great umami carriers in this dish; their so-called fishiness quite gracefully fades—actually disappears—in the cooking. You will regret, woefully regret, omitting them.

I often cook this as the centerpiece for my family’s Christmas dinner. I’ve roasted a fair number of legs of lamb over the years. Combine any oohs and aahs from roastings past and, altogether, they do not equal those that grace this recipe and me on Christmas night.

Roast Leg of Lamb Roman Style

Serves 6-8

Ingredients

6 garlic cloves, peeled

6 anchovy filets, drained or lightly rinsed

1/4 cup olive oil

1/4 cup loose rosemary leaves

1 teaspoon kosher salt

1 teaspoon black pepper

1 boneless leg of lamb (anywhere from 4-5 pounds)

1 cup white wine or apple juice

Directions

Make a paste of all the ingredients except the lamb and wine or juice, using a food processor and scraping down a few times, or a large mortar and pestle or molcajete. Untie the lamb or remove the flexible skein used to bind it (rinse and save the latter if that’s how you bought it) and lay it out as flat as possible. Rub the paste all over the lamb, saving back a couple of tablespoons.

Roll up the lamb and retie with kitchen twine (or insert back into the skein), rubbing the exterior with the reserved paste. Place on a rack in a roasting pan and let the lamb sit for 1 hour at room temperature.

When ready to roast, preheat the oven to 425 degrees. Pour the wine in the roasting pan and put the lamb into the oven; roast for 15 minutes, then turn the temperature down to 325 degrees. Roast until the interior temperature on an instant-read thermometer reaches 125 degrees for medium-rare, anywhere from 1 and 3/4 to 2 hours or so. Remove from the oven and let the lamb sit, loosely tented in foil for at least 30 minutes. It will continue to cook a bit as it rests (at least by 5 degrees’ increase) so be sure not to leave the initial roasting too long.

You may reach Bill St John at [email protected]