Exploring Flavor Space with David Zilber & Jason White

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Fermentation opens a culinary Pandora’s Box says David Zilber, head of fermentation at Noma restaurant in Denmark. Instead of just pureeing or heating a berry, the berry can be juiced for alcohol, transformed into vinegar, preserved for a fish sauce, pickled or dehydrated.  

“Fermentation was a discovery of possibility,” said Zilber. “You see the recommitorial power that comes from fermentation. It’s not just a subset of cuisine in gastronomy, it’s honest to goodness as large or it not larger than the world of gastronomy itself.”

Experimenting with ingredients that lead to tasteful outcomes is why “fermentation is so thrilling to explore” Zilber told Harvard students at Harvard University’s Science and Cooking Lecture Series. Zilber lectured with former Noma colleague Jason White, head of research and development at the Kudzu Complex in Tennessee.

Experimenting in the Noma Kitchen

Their topic: “Exploring Flavor Space: Innovation through Tradition in Noma’s Fermentation Lab.” The two shared fascinating insight into Noma, the two-Michelin-star restaurant regarded as one of the best in the world. But how do cooks toy with fermentation when the Michelin guide historically values consistency? Thousands of experiments and variations. Only 5% of what the chefs in Noma’s fermentation lab creates make it onto a plate.

“If you’re not trying to keep things traditional, you’re free to do whatever you want. And that’s the beauty of fermentation for us,” Zilber said. “When Noma employs fermentation, we do it knowing that we can change things. That we can seek out flavors by looking to old techniques, by turning to tradition, breaking down processes via reduction, pulling them apart, saying what enzymes are at play? What molecules are in the mix? What byproducts can be produced?”

Zilber showed the huge shared file between Noma employees of recipe trials. Things like moose snout, moldy vegetables, roasted pinecone, egg picked in elderberry juice and pig meat fermenting in its own pancreas enzyme. One of Noma’s early successes was adding a few drops of a fish sauce to a dish. A few drops of a potent fish sauce iteration goes a long way when flavoring a meal. The cooks began creating fish sauce equivalents, like a fish sauce from squirrel, sea cucumber, beaver, sea star, reindeer, wild boar, razor clam, bear (“That was the worst thing we’ve ever tasted,” Zilber said, “that did not go right.”).

“These were huge discoveries for us at Noma because, all of sudden, you could have a primarily vegetarian cuisine that had all the flavor and impact of like a full plate of food with meat and starch and vegetables just by using seasonings,” Zilber said. “And kind of flipping the role of meat and vegetables on its head. Suddenly vegetables didn’t have to be the accoutrement that just served to kind of temper what you were chewing in your mouth and act as the texture. They were actually the starring role, but you were as satisfied as eating a full plate of sliced sirloin because you could have this taste of meat permeating through your samphire mixed with watercress emulsion.”

Fermentation is the most useful tool for the restaurant, Zilber said. Noma has what he calls a “DIY or die” attitude.

When Noma chef and co-owner Rene Redzepi opened the restaurant in 2003, he wanted to create a fine-dining experience concentrating on the food of the Nordic region. Fine dining in Denmark, Sweden and Norway was primarily French food because the cold, coastal Scandinavian countries have such a short growing season. Redzepi and the cooks dove into cultural recipes. They contacted local foragers, then experimenting preserving the ingredients they’d find. They started a Noma Food Lab to catalog the different ingredients.

“When you taste all the products of fermentation, you understand it is delicious because it is that heightened level of food. All life is transformation – creation and destruction are just two sides of the same coin. Building things up in a certain way is just half of the picture if you understand you have to break them down first. And when your body understands that something has been broken down for it in a friendly manner by something that isn’t harmful in any way, alarm bells go off and you understand these things to be delicious.”

“That search for that flavor…is how Rene and the team back in the test kitchen in those early days learned to use the very paltry pantry that sat at Noma’s disposal with all these Scandinavian ingredients and multiple them many times over w the dimensionality of flavor that fermentation could provide. If at first, they only had in a season 250 ingredients to work with, they could turn to fermentation and all the different processes at their disposal to turn those 250 into 1,000.”

During the Harvard lecture, White made a koji and miso for the students to sample. He detailed creating miso from unconventional protein-rich foods, like seeds, roots, parsnip, corn, fava beans, byproducts from oil extracted from nuts.

Transformation through Fermentation

“A field is a field and a plant is a plant. It’s only a weed if you choose to pull it out. But it’s a crop if you put it there and want to harvest it at the end. That’s exactly how you have to think about fermentation,” said Zilber.

Zilber said the technical, chemical definition for fermentation is the anaerobic, enzymatic pathway that yeast uses to metabolize glucose and transform that into alcohol in the absence of oxygen. Simply put, it is the transformation of one food into another by a microbe. But those definitions don’t go far enough to describe fermentation’s complexity.

“If you want to get really into it, you do have to talk about human intent,” he says. “And humans have a big part to play in fermentation because, without the human willing the fermentation into existence, you just have a free-for-all.”

Zilber uses the analogy that a fermenter is like a bouncer at a night club. The fermenter has to decide between the troublemakers and the enjoyable customers. Who is going to come in and start a bar fight and who is going to come in and order drinks and mingle with other customers?

“The club is all the food you’re looking to ferment, the ingredients you’re looking to transform, and which microbes to keep out,” he said. “The key to cooking with microbes is cooking with life. You need to keep these creatures alive so they do the cooking for you.”

Control points are key to a fermentation. Lactic acid – the metabolic process that converts sugar and glucose into energy – has five basic needs. Access to oxygen, salt concentration, pH levels, nutrient sources and temperature. Every control point and process will lead to a different fermentation outcome.

“You’re trying to build an environment for that microbe to survive,” Zilber added.

Harmful pathogens won’t grow in a controlled fermentation environment. Mold can’t live without oxygen. And botulism has a higher water activity level than lactobacillus, and water activity level drops once salt is added in fermentation.

“You’re cutting off at the pass any malevolent microbes that you think might grow,” he said.

Humans, he said, have domesticated the lactobacillus bacteria.

Use Tradition to Apply Fermentation Processes

Zilber knows fermentation is a trendy topic today, but he notes it’s been around since the dawn of man.

“The first real food technology we had for safe food preservation before the USDA was a thing was fermentation,” he said. “And it makes sense that we do it until this day and we have all these traditional recipes on our counter tops because these are things that have kept civilization alive for a very, very long time. And we have grown up to actually love the taste of them and understand them as part of our cultural history.”

Before recipes were shared through the internet, cultures passed recipes through families. Fermentation was mastered because because a grandparent taught it to a grandchild. This is why towns in Italy have a sausage (Genoa, Calabrese) and towns in Japan have a Miso variety (Hatcho, Saikyo).

Cooking your own fermented product “is about crafting those environments that your microbes need to thrive.” Making a koji is recreating the ancestral field in humid China.

Noma is revolutionizing fermentation by using using traditional processes, then creating their own techniques. Noma uses biological and mechanical technology in their food to push the boundaries of cuisine.

“Noma applies the basic concepts of fermentation, of preservation, of making something last in a season where it normally wouldn’t be available, but taking it to the nth degree,” Zilber said. “No, it’s not always about combining flavors and seeing which is the best. Sometimes it’s combining technologies and seeing what produces the best flavor. We try all different sorts of extraction, sonication, vacuum filtration, the (supercritical fluid extraction systems) unit.”

Partnering with local Denmark bio-tech firms, Noma uses scientific technology to explore different fermentation projects.