“Foundations of Flavor: The Noma Guide to Fermentation,” by Rene Redzepi and David Zilber. Photographs by Evan Sung. Illustrations by Paula Troxler.

Rene Redzepi is tired. He’s poured himself into a curvy oversized booth at Kingbird, the Watergate Hotel restaurant that projects a cool, mechanical persona. Coiled metal tree trunks sprout from the floor. Large, abstract pine cones, also made of metal, hang from the ceiling. Dreamy, detached pop music floats from the sound system. It’s too much for Redzepi on this morning. He just wants two eggs and some fresh slices of avocado. Maybe rye bread, if you have it.

The co-founder and driving force behind Noma, the Copenhagen fine-dining destination that has been named the world’s best restaurant four times, is touring Canada and the United States with chef David Zilber, the head of Noma’s fermentation lab. Washington was the eighth city the pair had visited in the past 10 days while promoting “Foundations of Flavor: The Noma Guide to Fermentation,” a recently released tome that adds to the growing literature on fermented foods, including books by Sandor Ellix Katz and Kirsten K. Shockey and Christopher Shockey.

Rene Redzepi. (Photo by Laura Lajh Prijatelj)

“The Noma Guide to Fermentation” is part textbook, part cookbook and an altogether thorough examination of the seven fermenting processes — like garum, a controlled decomposition of proteins in salt and water; think fish sauce — that contribute the waves of flavor found on every Noma dish. How important is fermentation to Noma? Redzepi says ferments have surpassed foraged ingredients as the most important elements of the Noma pantry, the one that pioneered New Nordic cuisine in a landscape that is largely barren of fresh foods in winter.

Below is an edited transcript of our interview at the Watergate, where the chefs were joined by Redzepi’s wife, Nadine, who is traveling with her husband.

As you were working on this project, did you get a sense the market was ready for a book on fermentation?

Redzepi: Yes. I mean, I had to convince the publisher a little bit. The editor was a little bit like, “Oh, I’m not sure.” We had already decided that we wanted to do this series of books that were informative and practical. Not just books where you can look at pictures. But what should the first one be? That was the big question. I think the easiest would have been a vegetarian cookbook because that’s very trendy. I was very adamant that fermentation is a field that’s going to keep growing, and a book like this is going to help push it forward.

Unlike many cookbooks, this one doesn’t offer immediate satisfaction. These are projects. It’s almost counter to the way we live now.

Redzepi: Fermentation is the last sort of analog thing out there. Maybe cooking is the last true analog thing. Everything is so computerized.  Things are made with machines, and robots are taking over. If you want to make this, you got to use your hands.

Zilber: It goes completely counter to the spirit of the modern world.

You have said fermentation has surpassed foraging as the most important part of Noma, and yet I’m not sure that perception is widespread. Do you think it’s because fermentation is more invisible on the plate?

Zilber: The way we use ferments, it’s very much behind the scenes. Yes, there were the ebelskivers brushed with garum. But even from when I started, in the beginning of 2014, I remember you [Redzepi] in one meeting, saying, “Guys, chill out explaining that things are fermented on dishes.” Because it’s so much now, it’s going to defeat the purpose if we keep bombarding people and saying, “This is a fermented pickle here and a fermented sauce.” Just talk about the ingredients and let the fermentation speak for itself.”

Given the recent U.N. report on climate change, have you considered how ferments could get people to eat more vegetables and cut down on the environmental impacts of meat eating?

Redzepi: We have, actually. I totally believe this is the key, man, that can unlock a lot of these challenges in eating more plants. I really do. You add flavor. You add the thing that is missing sometimes when you have just a vegetarian meal.

Right. You’re not getting all the changes that occur when cooking meat — the caramelization, the Maillard reaction, which add flavor to a dish.

Zilber: If you have the right ferments, those flavors are in the ferments. That’s the point. You get the flavor of roasted meat.

Redzepi: There is the egg-white garum or the yeast garum that we do. They taste like meat.

David Zilber (Photo by Evan Sung)

Zilber: As these garums ferment, any protein within either the yeast cells or the egg white starts being broken down by enzymes. You are liberating the glutamate that’s bound up in the skin or flesh. You’re making MSG. My favorite application of fermented food was the old cabbage dish that we had on the menu. You’d take a cabbage leaf, just slather with peaso [a yellow split-pea miso] and parsley oil and grill it. People would freak out. They’re like, “You’re serving me a leaf?” Then they eat it, and they’re like, “This is a leaf?!”

Have you reduced the amount of animal proteins you serve because of the fermentation program?

Redzepi: We have a lot of animal protein right now because it’s obviously the game season. But I guess if you look at it over a year, we serve much less animal protein than what we used to because we have the long vegetarian season, which is basically from May until September. But, you know, we are toying with the idea that maybe our future is vegetarian. When I first told Nadine about this, I said, “We’re going to become a vegetarian restaurant.”

When was this?

Redzepi: Almost six years ago.

And what prevented you from doing so?

Redzepi: It wasn’t 100 percent clear whether we could do it.

Do you see Noma becoming a vegetarian restaurant?

Redzepi: This is about figuring out what makes sense for us long term and what sort of restaurant we want to be. And at the same time, it has to be exciting for us. It shouldn’t feel like a chore. You can eat a vegetarian meal all year long, easily, but can you have a tasting menu that’s full of 25 dishes that are delightful and varied, that’s as good in February as it is in August? Honestly, you’ll have to import ingredients.

It would be a different model from you have currently.

Redzepi: It would be a different model if we were open all year long. You could say it’s more European during a certain period.

It would require a sacrifice on your part: to relinquish Noma’s Nordic identity. Could you do that?

Redzepi: I don’t know yet. Those are all the questions that we are figuring out. We’ve moved past the idea of only serving Nordic ingredients for a while now. We’re, of course, very local because it makes sense for freshness and for the community. It is our identity. But obviously were we to have a menu where 95 percent of all the ingredients come from the market in Nice, that’s, like, whoa, I don’t know about that. That seems so bizarre, right?

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