The Story of Sushi (3 page)

‘T
hese are bonito flakes,’ Zoran explained, showing the students a bag of fluffy beige flakes. He was teaching them to make a broth called
dashi.
Dashi is highly flavorful, and it is a cornerstone of Japanese cuisine. Dashi is the soup base to which miso is added to make miso soup. Like soy sauce, dashi plays a supporting role in sushi, but the method for making dashi is very different.

First, Zoran had simmered slabs of kelp, a type of seaweed with broad leaves. Now he switched off the heat and sprinkled the bonito flakes into the pot. Kate watched the flakes melt into the steaming water. She gathered that bonito was a kind of fish. She’d seen those flakes before, sprinkled on food at Japanese restaurants. She’d always thought they were bacon. After a few minutes, Zoran removed the kelp and bonito flakes with a strainer. The remaining broth was dashi.

Kelp—like miso, soy sauce, cured ham, Parmesan cheese, and tomatoes—is loaded with tasty glutamate. Called
konbu
in Japanese, kelp is the first half of what makes dashi delicious.

The second half of dashi’s magic is the bonito flakes. Bonito are a type of tuna, also called skipjack tuna. Like their larger tuna cousins, they swim fast, sometimes in bursts that reach 40 miles an hour. They accomplish this feat by loading their muscles with high-energy power pellets that provide fuel to their cells. These power pellets are called ATP—adenosine triphosphate.

The manufacturers of bonito flakes simmer fillets of bonito
before smoking the fish for ten or twenty days. Like the makers of miso, they infect the fish with mold and lock up the fillets in a box. After two weeks they pull out the moldy fillets and lay them in the sun. They scrape off the old mold, add new mold, and lock them back in the box. They repeat this procedure three or four times.

Just as with miso and soy sauce, digestive enzymes break down the proteins in the fish into tasty amino acids. The ATP gets broken down into a series of other molecules, resulting in a delicious compound called inosine monophosphate, or IMP, which the human tongue savors nearly as much as glutamate.

After a few months of molding and drying, the bonito fillets are hard, like pieces of wood. To make the flakes, the fillets are shaved with a tool like a carpenter’s plane.

Dashi’s role in sushi usually goes unnoticed, particularly in the United States. Most Americans think they are supposed to dunk all their sushi in soy sauce. But full-strength soy sauce overpowers the delicate flavors of raw fish. A good sushi chef adds all the flavoring the sushi needs before he hands it to the customer. He mixes his own sauce and uses it behind the sushi bar. This sauce is called
nikiri.
Each chef has his own secret formula. Most are a variation on a standard recipe, and dashi is a key supporting actor. To 100 parts soy sauce, the chef adds twenty parts dashi, ten parts sake, and ten parts mirin, a sweet rice liquor used in cooking. The mixture is heated and reduced briefly, and is then ready to use.
Nikiri
is a kinder, gentler, and more complex soy sauce, with a broad array of flavor compounds appropriate for enhancing sushi.

The Hama Hermosa restaurant attached to the California Sushi Academy provided its customers with straight soy sauce. But at the sushi bar, Toshi and the other chefs frequently painted a sheen of
nikiri
across the top of pieces of sushi with a basting brush. This was the traditional method of seasoning sushi. The chefs were forever handing sushi to customers and admonishing them, “No soy sauce!” Most sushi chefs in America don’t make this effort.

The deliciousness of dashi and soy sauce intrigued a Japanese chemist named Kikunae Ikeda, who in 1908 figured out that glu
tamate is what makes kelp broth so delicious. He realized that the stuff could be manufactured. The product was called monosodium glutamate, or MSG.

A few years later, a colleague figured out what made bonito broth so tasty. It was the IMP. Much of what makes all fish delicious is IMP, created when the ATP in the fish’s muscles breaks down after the fish’s death. Scientists discovered that IMP could be manufactured, too, and like MSG used as a flavor additive.

Western scientists believed that the human tongue could taste only four fundamental flavors: sweet, salty, sour, and bitter. The Japanese scientists argued that there was a fifth fundamental flavor, triggered by amino acids like glutamate and compounds like IMP, and epitomized by foods such as dashi and
nikiri.
They called this fifth flavor “tastiness,” or in Japanese,
umami.

For decades, Western scientists were skeptical that
umami
was a fundamental flavor. Finally, in the past few years, scientists at the University of California, San Diego, have demonstrated that the tongues of humans and other animals possess specific receptors for
umami.

Today, MSG is manufactured by the ton and added to all varieties of processed foods. Most Americans associate MSG with Chinese food, but it is also added to canned foods, soups, salad dressings, chips, and fast food. On product labels it is usually disguised as “hydrolyzed vegetable protein.” It is even added to much of our processed meat and poultry because modern industrial production has robbed animal flesh of its own flavor. The Buddhist vegetarian condiments of ancient Japan are now used to make American factory meat palatable.

After class, Kate drove to McDonald’s, as she’d been doing every day after class. She bought a Big Mac. She drove home. She sat on the one chair in her lonely little house in Torrance, surrounded by her unpacked boxes. She stared at the floor and slowly chewed her Big Mac.

After two weeks at the academy, Kate was afraid her family had been right to be skeptical. During the second week, the classes had
covered more basics of Japanese cuisine. None of it had much to do with sushi. Every day she wondered what she was doing there. She had given up everything in her life that she knew and entered a world where she didn’t belong.

At least the Big Mac felt familiar and comforting. One of the ingredients of its “special sauce” was hydrolyzed vegetable protein.

Friday morning, at the end of the second week, Kate dragged herself back to class. Zoran announced that they were going to make sushi—finally. He gave the students a crash course in
nigiri
and
te-maki,
or “hand rolls.”

Nigiri
are the little rectangles of rice topped with slices of fish and other toppings that sushi chefs squeeze together with their fingers. Hand rolls are an informal sushi roll that don’t require a bamboo mat to make. The chef places half a sheet of nori—the crisp, dark-green Japanese seaweed paper—on his palm, presses on a blob of sushi rice and a piece of fish, and rolls it up like a waffle cone. The
nigiri
and hand rolls that Kate made looked ragged and fell apart.

Then Zoran told the students why he was teaching them to make
nigiri
and hand rolls. The next day—Saturday—Toshi, Zoran, Jay, and all the students would load the restaurant’s catering equipment into a truck and drive to Hollywood, to the studio lot at Paramount Pictures, to serve sushi at a party for 3,000 people.

J
ay wasn’t just the academy’s coordinator for student affairs. He also handled myriad other tasks for Toshi’s restaurant and school. On Friday afternoon at the end of the second week of the semester, Jay loaded eight blue insulated bins into the academy’s old van. Imported from Japan, the bins were labeled “Sanitation Listed Food Equipment.” They were designed for keeping rice at body temperature—the ideal temperature for serving sushi.

Jay drove along a wide boulevard lined with the strip malls characteristic of Los Angeles. He knew that many of the generic storefronts hid hole-in-the-wall eateries that served authentic ethnic cuisine, often next to restaurants serving fast food or Americanized imitations. Some of the best sushi in America was hidden in L.A.’s strip malls—along with some of the worst.

Food fascinated Jay. He was the kind of guy who, if he heard that the best Mexican tacos in L.A. were being served from a truck in a distant suburb, would drive out and try them. During college, Jay had worked in the kitchen of a Japanese restaurant. If he didn’t prepare a dish perfectly, the chef would scream and throw the dish back at him.

Jay’s interest in sushi had begun only about five years ago. He attended the California Sushi Academy, then worked for Toshi in
the kitchen. Next, he worked behind the sushi bar and then taught at the academy. Now, he served part-time as the academy’s coordinator for student affairs and filled in around the restaurant. The rest of the time he ran his own consulting business, giving advice to restaurateurs who wanted to open sushi bars.

Jay was American, but his ancestors were Japanese. As he’d learned more about sushi, he’d become worried about the state of sushi in the United States. He would sit at a sushi bar and see people stirring globs of green wasabi paste into their soy sauce to make a thick gray goo. They’d slather their fish with the goo, eat it, and exclaim, ‘Oh, that’s such good fish!’ Jay himself used to do the same thing.

But now Jay knew that this behavior was distressing to the chef. Wasabi is a type of horseradish, and in the quantities required to make that thick gray goo, the spiciness of wasabi overwhelms the human capacity for taste and smell. The chef might have risen at 4:30 that morning to go to the fish market and haggle over the best fish, only to see his customers slather it with wasabi so they couldn’t even taste it. Jay believed chefs were becoming disillusioned and customers were missing out. Americans liked food that was hot and spicy, but there was so much more to sushi than that.

Jay had learned that in Japan, sushi chefs might put a touch of wasabi inside a
nigiri,
using a larger dab of wasabi with fatty fish, and a smaller one with lean. But they never served extra wasabi on the side. They would serve a pinch on the side with sashimi—plain raw fish, without rice. But diners certainly weren’t supposed to mix the wasabi into their soy sauce and apply it indiscriminately.

Another thing Jay noticed was people gobbling up the pickled ginger as an appetizer. But the point of the ginger was to cleanse the palate between servings of different kinds of fish. Not eating a slice of ginger between each type of fish, Jay felt, was like mixing five different wines and trying to taste the Chardonnay.

He’d also see diners dunk the rice side of their
nigiri
in the soy sauce, instead of the fish side. Or they’d eat the
nigiri
in two bites instead of one. Or they’d force themselves to use chopsticks, when in fact most Japanese people just use their fingers to eat sushi.

Jay noticed, too, that people automatically assumed sushi was good for them. But in the United States, the most popular form of
sushi was big sushi rolls, loaded with carbs, sugar, fat, and sodium. A sushi takeout box at an American supermarket could easily contain as many calories as two slices of pizza, and the rolls served in restaurants are often worse.

At the sushi academy, Jay would watch each new batch of students with interest. Most of the students were American in one way or another—sometimes Asian American, sometimes Caucasian. A few African Americans had attended the school. One woman had come from Barbados. Some of the students came from Europe. Some were global citizens, others were local in their outlook. Almost none was in any sense traditionally Japanese.

As Jay observed the waves of students coming through the school, he came to think that people who were not traditional Japanese chefs might communicate better with American customers. This new generation was more familiar with American culture and the English language. The trick was to teach them Japanese traditions so they could master authentic sushi.

Jay’s thoughts returned to the eight blue insulated bins sitting in the back of the van. He had arrived at his destination. He parked the van next to a nondescript one-story warehouse of red brick and stepped through an unmarked side door into a hallway. Rows of shoes sat on shelves, neatly arranged in pairs. Workers in white aprons and white rubber boots shuffled along the hall, their hair tucked into bouffant caps and their faces hidden behind sanitary masks. This was the California Rice Center, a hub of L.A. sushi. Down the hall was a cavernous factory that produced sushi rice on an industrial scale.

The modern term “sushi” refers not to fish, but to rice—rice seasoned with rice vinegar, sugar, and salt. Any food made with this seasoned rice can be called sushi, whether it involves fish or not.

Traditionally, sushi apprentices in Japan spend up to two years simply learning to cook and season the rice before they’re allowed near the fish. Master sushi chefs agonize over their sushi rice, perfecting secret recipes. In the old days, the larger sushi shops in Japan employed full-time specialist chefs whose only job was to prepare the rice.

This is ironic, because the original sushi chefs threw the sushi rice away.

About 140,000 years ago, people in what is now Japan probably ate a lot of roasted elephant. After the earth’s climate shifted, they switched to acorns, which was surely a step down. To supplement the acorn diet, they hunted wild boar. They also dug in the coastal mud for clams and rowed out into the ocean in dugout canoes to harpoon bluefin tuna and catch bonito with wooden hooks. They dried the red fillets in the sun to make jerky. In those days, the closest thing a Japanese person had to sushi was a strip of tuna jerky wrapped around an acorn.

Even after the Japanese learned to grow rice—probably around 400 or 300 BC—early sushi didn’t involve tuna or any other ocean fish. Sushi began inland. Historians think it was first invented along the Mekong River, in what is now landlocked southern China, Laos, and northern Thailand. No one knows just when, but it was after rice cultivation began in the region; remains of rice have been located in northern Thailand dating back to 3500 BC.

The people along the Mekong River caught freshwater fish. During monsoon season, the rivers would flood into the rice paddies, and fish would swim into the rice fields. Soon the farmers were raising fish in the paddies along with the rice. But the supply of fish came and went, and the farmed fish had to be harvested at the end of the rainy season, before the rice paddies dried up. The dilemma was how to store fish for later consumption. Near the ocean this wasn’t a problem because people could catch fish all year.

The inland folk packed the whole fish, including its guts, in a large amount of salt. Guts contain digestive enzymes. These enzymes, along with other enzymes in the fish’s flesh, broke the proteins of the fish down into amino acids. The salt prevented harmful bacteria from growing. The result was fermented fish paste. This was how Asian fish sauce got its start.

But large amounts of salt could be hard to come by. This technique also obliterated the fish itself, creating a slimy, stinky mush. In Japan, a version of it is still eaten today, called
shiokara.
People who try it for the first time usually want to throw up; that said, fermented fish paste has enjoyed surprising global popularity. A
nearly identical product, called
garum,
was one of the most popular cooking ingredients throughout the Roman Empire.

The inland rice farmers along the Mekong River discovered a second way to keep their fish edible for long periods. This method kept the fish in one piece and left it much less stinky. First, they gutted and cleaned the fish. Then, they packed it in cooked rice and sealed it inside a jar. They cooked the rice first because they wanted it to decay.

Inside the jar, mold quickly digested the carbohydrates in the rice, breaking it down into sugars, just as in the making of miso. Then yeasts ate the sugars, creating alcohol. The alcohol protected the remaining sugars from the bacteria in the air inside the jar.

With the notable exception of botulism, many nasty bacteria—the ones that spoil food—need oxygen. Many benign bacteria don’t; they probably first evolved inside piles of rotting vegetation. In the rice in the jar, these nicer bacteria digested the sugars. They gave off lactic acid and acetic acid as waste. By now the rice was horribly sour. A Japanese source from the twelfth century describes it as “no different from the vomit of a drunkard.”

But acids do prevent food from spoiling. When a bacterium runs afoul of an acid like lactic acid or acetic acid, the acid shoots hydrogen ions into the bacterium. The ions disable the cell’s machinery and wreak other havoc, and the bacterium dies. Inside the jar, the fish was surrounded by acids in which very few bacteria could survive, and there was no oxygen for them, anyway.

The fish didn’t stay perfectly fresh, of course. Digestive enzymes broke down most of the proteins. But the fish would keep, and stay in one piece, for as long as a year.

When the inland farmers wanted to eat the fish, they opened the jar, cleaned off the gooey, vomit-smelling rice, and threw it away. The fish tasted pretty good—today it would strike us as a bit like a pungent aged cheese, with butter and vinegar overtones.

This original form of sushi spread to China, and then to Japan. Apparently the Japanese considered it a very special meal. By the year AD 718, a Japanese government document said people could use sushi to pay their taxes.

No one is certain where the Japanese word
sushi
comes from. One of the Chinese words for preserved fish was probably pronouced
something like
chee.
In Japanese, that sound could have become
shee,
supplying the second syllable of the word
sushi.
The first syllable might have come from the Japanese word for “sour,”
suppai,
making
su-shi
to be “sour preserved fish.”

In Japan, people gave this original form of sushi its own name—
nare-zushi,
which means “aged sushi.”

The Japanese began to use shellfish from the ocean to make
nare-zushi,
too, including abalone and mussels. But until the end of the ninth century, most of the fish in sushi continued to be freshwater fish from lakes and rivers rather than ocean fish.

While sushi was adopted in Japan, it disappeared in China. Possibly this was because Genghis Khan and the Mongols conquered China, and they preferred red meat to fish. But the original form of sushi is still eaten today in Thailand, as well as on the island of Taiwan off the southern Chinese coast.

It is also still eaten in Japan. The Japanese make the original form of sushi from freshwater fish—in particular, a species of carp related to goldfish. The fish are called
funa. Funa-zushi
remains on the menu to this day at restaurants and shops around Lake Biwa, near Japan’s ancient capital city of Kyoto.

Lake Biwa, closer to Kyoto than to the sea, is Japan’s largest lake and throughout history probably provided a steady supply of fish. Gradually, people who could command the luxury of regular deliveries of fish—probably aristocrats in the capital—began to eat
nare-zushi
sooner and sooner in the fermentation process. They didn’t have to worry about preserving the fish for long periods.

By the 1400s or so, these people were eating
nare-zushi
so early in the process that the interior of the fish’s flesh remained relatively fresh. They discovered that the rice itself, though fermented, was still edible and quite tasty at the earlier stage. The flavors of this food were different: tart, slightly acidic rice, and fish that tasted fresher and less cheesy.

By 1600, people were calling this lightly fermented mixture of fish and rice
nama-nari
(or
nama-nare
), which translates roughly as “ready raw” (or “raw aged”). For
nama-nari,
the fish and rice were aged for a month or less, and sometimes as briefly as a few days.

The original form of sushi had been a side dish. Now it became a self-contained meal of fish and tart rice. This form of sushi was a
luxury, not a necessity. Sushi makers began to entertain their aristocratic customers with new ingredients, including ocean fish.

A dramatic new development took place around 1600. People fermenting sake figured out how to age the dregs from the rice liquor, add new bacteria, and ferment it further to produce acetic acid. This is when rice vinegar was born, and it was delicious. In addition to acetic acid, it contained some seventy other flavor components—amino acids, organic acids, sugars, and esters. In the second half of the 1600s, a doctor for the shogun tried adding vinegar to sushi rice. He discovered that the uniquely tart taste of sushi rice no longer required fermentation at all. Instead of packing fish in rice and letting it sit around until bacteria produced lactic acid, sushi makers could just splash on the convenient new liquid. They achieved a similar taste instantly, with the acetic acid in the vinegar. The acids in the vinegar helped to prevent the rice from fermenting in the first place because they killed bacteria. The purpose of the rice in sushi had been completely reversed. The new sushi, fresh instead of preserved, grew popular. People called it
haya-zushi
—“quick sushi.”