Authors: John McQuaid
The first batch of
butabushi
had been a lark, but Felder, taking over, resolved to proceed methodically. He ran a series of experiments to assess
Pichia
's flavor-making abilities against the standard,
Aspergillus
. The results were disappointing: like an out-of-shape jogger competing against an experienced marathoner,
Pichia
performed miserably. In one test, Felder inoculated pork and beef with both molds.
Bushi
made with
Aspergillus
was superior in every wayâtaste, aroma, texture, and consistencyâto that made with its rival.
Aspergillus
's
long history as a fermentation agent made it reliable and predictable; it produced consistently nice flavorsâÂsurprisingly, even in the unfamiliar territory of a new kind of meat. This was another new way to make
bushi
, and so had to be considered a success. But Felder was disappointed the
Pichia
had failed.
When he tried to re-create the flavor of the original
butabushi
, his efforts brought further grief. It didn't taste the same. “It's not the same environment, it's not the same ecosystem that allowed it to become the dominant catalyst the first time,” Felder said. “We had isolated one variable, but not all of the others.” In other words, it wasn't the
Pichia
alone that created the flavor the first time but its interactions with the other organismsâthe chemical symphony of many metabolisms acting together.
These disappointments still offered valuable insights.
They showed that microbes could not easily be brought to heel, while also suggesting a vast terra incognita existed for flavor and cuisine. “We know so little about endemic microorganisms,” Felder said, “that there's limitless potential for what flavor compounds could be created.”
Felder kept up his microbial tinkering. (He also published a scientific paper on this work titled “Defining microbial terroir: The use of native fungi for the study of traditional fermentative processes.”) He made chicken
bushi
(a good flavor profile, but poor texture) and, after many failed tries, produced a decent beef
bushi
(a slight iron-liver flavor, but good texture). He swapped ingredients out of traditional Japanese foods to see what would happen: instead of rice, he used spelt, freekeh (a roasted green wheat), farro (a whole form of wheat), rye, barley, and buckwheat. Instead of soybeans, he tried pistachios, cashews, pine nuts, lentils, chickpeas, and red beans. Felder's pistachio miso was green. It took many attempts to get it right, but it has become one of Momofuku's signature foods, the sine qua non of its scientific fermentation efforts. Felder put a dollop of it on a spoon and I tried it. It was sensational: rich, yet light; complex and earthy, yet vivid.
â¢Â â¢Â â¢
Dutton, meanwhile, expanded her microbial detective work from
bushi
to cheese. Two, sometimes three or more types of fermentation are employed to turn curds, the bland, chunky solids from milk, into a hunk of flavorful cheese. Several distinct communities of fungi and bacteria overlap and interact. And yet, “Cheese is relatively simple,” Dutton said. “If you compare the number of species of microbes in the human gutâin the hundreds if not over a thousandâto cheese, there are about ten. But because you have this simplicity and
stability, when you make small changes there is huge flavor diversity.”
She began to collaborate with Jasper Hill Farm, an artisanal cheese maker in Greensboro, Vermont. Before dawn each morning, the staff pumps the milk from forty-six Ayrshire cows into a three-hundred-gallon vat in an adjacent farmhouse to be made into cheese. The warm milk is immediately seeded with a mixture of lactic acid bacteria, yeasts, and ripening agents. As bacteria begin to break lactose down to lactic acid, the milk turns sour. After about five hours, rennet, the solidifying agent, is added. One morning when I visited, cheese maker Scott Harbour dipped a knifelike tool into the milk, testing for signs the fats were about to condense into curds: a few minutes later the tank contained a shaking, shimmering solid. Harbour and a colleague hand-cut and lifted big hunks with the consistency of aspic onto stainless steel counters. It was mushy and mild, with only the slightest hint of acidity. The cheese makers compressed globs into cylindrical molds, which are set aside and flipped on a schedule so the whey drains out evenly, creating a consistent texture: a three-dimensional canvas for what comes next.
I had brought my twelve-year-old daughter, Hannah, to watch cheese being made. She loved comfort food, and cheese in particular, things with subtler, richer flavors harmonized by umami. If she had her way, her diet would be macaroni and cheese, grilled cheese sandwiches, quesadillas, pizza, and cheese ravioli dosed with Parmesan. It was hard to get her to eat anything else, and her pediatrician became concerned about the lack of variety. Eating less cheese only strengthened its allure, and it became a source of mordant comedy. She adopted “cheese” as a catchphrase and made her online avatar a wedge of Swiss.
At Jasper Hill, they were making a soft cheese named Winnimere. After the whey drains, the semi-solid cheese cylinders, about five inches in diameter, are cut into small wheels. In the basement, the next phase was under way: cheese makers wrapped a narrow strip of spruce bark around each wheel. They handed Hannah a hat and apron, and she started wrapping and snapping the bark in place with rubber bands. The bark helps it keep its form, while imparting a sappy, woody flavor and a set of microorganisms to the surface. As the cheese ages, these microbesâmainly penicillin moldsâform a hardening rind with a mushroomy flavor. Sometimes a virus gets into a batch, infecting both molds and bacteria. The rind turns yellow and the flavor acrid, sour, and oniony. The molds also work their way inside the cheese, joining the lactic acid bacteria. Depending on the mix of microbes at each point inside, the flavor varies millimeter by millimeter.
Winnimere develops a signature sheen of pink and orange that is important for its brand identity, and catches the eye from crowded display cases. Dutton was trying to understand what, biologically speaking, those colors do. Her basic technique was straightforward: she grew cheese cultures in petri dishes, combined them, and observed their behavior. When she uncapped a dish, sharp, funky smells emerged with no cheese present. She walked us into a cool room where test cheeses are stored, dollops of curd arranged in a grid of tiny plastic wells, infused with different combinations of molds and bacteria. On one of them, a bright green penicillin mold grew next to a yellow colony of
Arthrobacter
, a common genus of bacteria usually found in soil. Dutton flipped the container over. A patch of bright pink was blooming out from
Arthrobacter
adjacent to another, unidentified mold.
“We want to know what that pigment is,” she said. “Why
[
Arthrobacter
] is producing it. Does the pigment do something? Is it producing it to maybe try and harm the mold because it doesn't like that it's growing next to it, or is it just some sort of general protective response?”
Some microbe species develop a mutually beneficial relationship with others to survive. Some just compete. Both kinds of interactions produce distinct colors and flavors. Understanding those relationships could allow cheese makers to fine-tune their microbe wrangling, expanding the range and shadings of taste. But there are many obstacles. Even known microbes interact with a slew of environmental unknownsâas
Pichia
was before it was identified. It might be something on the grass the cows eat, or an airborne germ entering the aging vaults. This adds a dose of randomness to every batch. Jasper Hill had plans to follow the technique Dutton brought to Momofuku, identifying the source of its homegrown molds and bacteria. Most American cheese makers get their cultures from European manufacturers. Knowing the local microbiome would enable them to patent a distinct Vermont terroir.
To produce that terroir, aging must be carefully managed so that the microbes flourish in just the right way. Zoe Brickley, who oversees this process, took us inside a Jasper Hill vault. A low ridge had been excavated into seven caves, each projecting into the earth at a different angle off a central axis. Naturally cool and moist, they allow Jasper Hill's cheese makers to orchestrate the emergence of flavor over weeks and months with environmental fine-tuning. Their temperatures range between 49 and 53 degrees, and the humidity is kept at 98 percent.
Wheels of clothbound cheddar, eighteen inches across and six inches high, were stacked on towering shelves. Virgin
wheels are pressed into a burlap band. Then circles of cloth are applied to the top and bottom and rubbed with lard. This keeps them from drying, and also creates a home for molds, which multiply and turn the cheeses fluffy as the months pass (they're vacuumed and scrubbed before they depart). Tiny bugs called dust mites burrow into the lard, exposing the burlap to air, which helps maintain the right balance of moisture on its surface. Ripening takes roughly a year: the cheeses on the shelves ranged from new to thirteen months old.
The air was loamy and thick, with a hint of ammonia and a floral scent from the mites. Flavors grew and morphed incrementally, each wheel on its own lonely trajectory. Brickley pulled one down, took out a small cheese-tapping tool, stuck it into the bottom, and extracted a sample. Unlike a typical mass-produced sharp cheddar, with a bitter tang and a hint of sulfur, this one was sweet, with a brothy, umami note. But it was also crumbly, a bad sign. “It's sandy, it has a broken quality to it,” Brickley said. “I don't see how that can get much better.” Bacterial fermentation had run wild inside this wheel, making more acid and reducing calcium and other minerals essential to a smooth texture. The next wheel was only a week younger, but it was completely different; like a civilization unto itself, each wheel's microbial community rises and falls in its own way. This cheese was smooth, with a hint of pineapple flavor. Still, something was missing. “There's not enough meat,” she said. “I think it'll get more meaty, like white miso. I think of meats in a flavor, with white miso being the lightest, then chicken broth, then maybe pork, then maybe red meat broths.”
Jasper Hill was founded by two brothers, Andy and Mateo Kehler. They have backgrounds in sustainable agriculture, but turned their attention to the microscale ecology of deli
ciousness. At one end, molds and bacteria battle; at the other, the pleasure networks of the brain respond. They know both are equally capricious. “I had a conversation with my six-year-old son last night. He's turned into a really picky eater,” Andy Kehler told us. “He says, âDad, I'm going to write a book about the best taste.' That was after he ate a couple of capers with mustard. It definitely wasn't his pork chop or his potatoes or the awesome mushrooms that we had last night. It was the caper.”
Deliciousness is a slippery concept. It is an ideal, something chefs aspire to create and everyone wants to experience. It can be roughly defined as what happens when food ingredients, preparation techniques, presentation, and the company of fellow diners merge to create a flavor that transcends its individual elements. Deliciousness is not merely tasting good; spices taste good, but are not delicious. As food manufacturers discovered, it requires a degree of complexity and contrast: varying tastes, aromas, and textures that alert the brain's pleasure centers, but also provoke the senses, keeping them a little off balance.
The new wave of culinary science aims to engineer deliciousness. The Jasper Hill staff taste-tests its cheeses and rates them with a detailed checklist. Their trained palates usually reach consensusâit's the near-great cheeses that provoke wild disagreements. To understand why, they turned to data. Jasper Hill began collecting and graphing all its ratings, making databases much like those generated by the white rats in Opertech's Philadelphia lab. The ratings are aggregated into a number called the Deliciousness Factor, or DF. It's a one-to-ten scale, with ten as the best possible incarnation of a particular cheese: a rare achievement. Sevens rank pretty well; sixes and fives are problematic. The data are also broken
down to analyze the problem areas. “Spider graphs” show a cheese's ratings for texture, sweetness, saltiness, rind development, and the trajectory of its ripening over time. Each data point spikes outward around an axis. The bigger and rounder the graph, the better the cheese. If something isn't right, the numbers are variable and the graph more jagged. The worst collapse back to the center, like a black hole.
The notion that something sublime like deliciousness can be precisely quantified seems a little absurd. But in the digital age, the world has begun to accumulate vast troves of data that contain hidden patterns of behavior. Graphing cheese flavors as they evolve exposes the flaws in the aging process, or a microbial breakdown, or a period of high humidity. What if Ârecipesâor entire cuisinesâcould be broken down the same way, their interior dynamics exposed by some digital wizardry?
A good recipe depends on the relationships between ingredients: how they chemically interact and change when mixed together and cooked and how the combination piques the senses. But like the buzzing of microbe metabolisms, recipes are scientific black boxes. Some general principles have been established, such as the Maillard reactions responsible for much of the flavor in cooked food. But the chemical dynamics of individual recipes, developed by trial and error and sips from the stirring spoon, remain obscure. Nicholas Kurti, of the molecular gastronomy movement, once said: “I think it is a sad reflection on our civilization that while we can and do measure the temperature in the atmosphere of Venus, we do not know what goes on inside our soufflés.”
Yong-Yeol Ahn, a physicist and computer scientist, had worked on computer models of metabolic processes and the dynamics of the social network Twitter before turning his attention to cuisine. These subjects may seem unrelated, but
each is a complex system with millions of moving pieces; their behavior often follows common, underlying principles that can be analyzed and understood.