The Story of Sushi: An Unlikely Saga of Raw Fish and Rice

by Trevor Corson

of saltwater, scraping his thumb along the shrimp’s tiny digestive tract to remove it.

Mackerel is perilous to serve raw. Mackerel is so difficult to keep fresh that Japanese chefs sometimes call it the fish that “spoils even while still alive.” Humans can also pick up more than fifty different parasites from eating raw or undercooked fish; removal of parasites can require surgery. A worm called anisakis is one of the most prevalent parasites, and

its larvae love living inside mackerel. The clever larvae of anisakis swim around looking delicious. They want to be eaten, and usually a small crustacean will oblige. The larvae live happily in the stomach of the shrimp or krill until a mackerel comes along and eats the crustacean. Then the larvae burrow into the lining of the fish’s gut or, less often, into its flesh.

Mackerel serve the larvae’s purpose only because sooner or later a mammal will eat the mackerel, preferably a dolphin, porpoise, or whale. Once in the stomach of a mammal, the larvae molt and become adult worms. The worms use a mouth like a boring tool to drill into the mammal’s stomach wall. ...

When a human eats an infested fish without cooking it, he feels a tingling in the throat, and within a few hours may suffer violent abdominal pain and nausea. If he’s lucky, he’ll vomit up the larvae.

If not, he’ll suffer for a week or so until the worm,

realizing that it’s not inside a dolphin, giv...

By then, the person’s doctor may have misdiagnosed the situation as stomach cancer. Even without swallowing a live larva, people sometimes react simply to the ch...

Nevertheless, sushi chefs continue to prepare and serve mackerel uncooked. In theory, salting the fish and then soaking it in vinegar may well kill the larvae, for the same reasons that salty and acidic environments kill bacteria. Salt sucks the water from cells, causing them to shrivel. Acids bombard cells

with hydrogen ions, warping their enzymes. Unfortunately, experiments have shown that parasitic larvae can survive for nearly a month in a 20 percent salt solution. Japan has one of the highest incidences of anisakis illness in the world—

“Saba is also very oily,” Zoran added. “About sixteen to twenty percent fat.

The marination

helps cut down on the oil. Saba also has a ve...

Fish that are alive, and fish that are freshly killed, don’t taste or smell fishy at all. A perfectly fresh saltwater fish emits two primary smells. One of these smells is the scent of the ocean—or rather, of the bromophenols produced by algae th...

leaves. The fats in fish are the unsaturated kind, as they are in plants. Fish skin and plant leaves both contain an enzyme that breaks unsaturated fats down into fragments that smell “greenish” an...

Soon after death, however, fish start to smell fishy. Fishiness comes from the same phenomenon that gives...

osmotic pressure of saltwater, sea creatures fill their cells with tasty amino acids. But fish in particular also fill their cells with a related amine called trimethylamine oxide, or TMAO. Unlike the amino acids, TMAO has no taste. Nor does it have any smell. But after the fish dies,...

from TMAO, leaving behind TMA. TMA by itself stinks. It’s what gives old fish their foul smell. It’s also present in human bad breath and in bacterial infections of the human vagina. A rare genetic disorder called trimethylaminuria can prevent people from metabolizing routine amounts ...

rotting fish. For obvious reasons, it’s a disorder that can caus...

In addition, bacteria on the surface of the fish quickly digest proteins in the fish after death, creating noxious fumes, including ammonia, putrescine, and cadaverine. Salting and marinating fish with vinegar doesn...

Covering fish...

heavy layer of salt draws moisture out of the flesh by osmotic pressure. As the water inside the flesh rushes to the surface to dilute the salt, compounds like TMA and s...

Meanwhile, the acetic acid in vinegar fires hydrogen ions at TMA, just as it does at bacteria. When a hydrogen ion hits a molecul...

gains a positive electrical charge, which allows it to dissolve easily in water, removing it from the ...

In fact, the sushi vendors on the streets of nineteenth-century Tokyo rarely served anything raw. They had no access to refrigeration. They salted and marinated—or

blanched, or seared—all their seafood so it would keep long enough to serve.

The need for preservation generally had a fortuitous effect; salting and marination often improve the taste and texture of raw fish.

One of the reasons for this is that muscle, like mold, contains

lot of enzymes. In muscle, enzymes convert fuel—sugar—into energy. Fish muscle, however, generally contains many more enzy...

This is partly because fish of many species lead lives of extraordinary self-sacrifice. They consume as much food as they can, building up their muscles and fat reserves, an...

T...

the end of these migrations they manufacture huge masses of sperm or eggs. When they run out of fat during these mating marathons, they literally start to eat themselves for the sake of the next generation. The many enzymes in their flesh deconstruct their own muscle proteins into amino acids. The fi...

The closer the fish get to spawning, the more wasted and frail they become. Like the enzymes in mold, the enzymes in fish muscle continue functioning even after the fish dies. As a result, cooking can actually ruin the taste and texture of fish. If you heat a piece of fish at too low a temperature for too lon...

itself right there in the pan. As with crustacean meat, t...

Salting raw fish at room temperature, however, lets the enzymes work slowly, deconstructing a little of the protein into the tasty components of umami. The salt fends off bacteria long enough for the enzymes to accomplish their task,...

to...

Vinegar, meanwhile, unfolds complex fish proteins, firming up fish flesh and turning it opaque. Early sushi chefs also marinated some of their fish in soy sauce to help it keep longer.

“To the Japanese, albacore is the lowest of the tuna—the worst!”

“But Americans like the flavor.” Albacore is most often canned as “white meat tuna.”

You can eat it raw, but because the flesh is so soft, we usually sear it.” Raw albacore tends to disintegrate under the knife. Searing tightens up the edges. It’s a bland fish, so searing also adds taste.

Sashimi didn’t have to be fish. It could be anything, even the meat of deer, wild boar, or birds.

Sashi means “to stick or pierce,” and mi means “meat.”

Unlike sushi, sashimi should always be eaten with chopsticks.

Zoran had placed his slices in the direction that a right-handed customer would approach with chopsticks. That was the easiest way for him to arrange them, and the easiest way for a right-handed customer to pick them

up.

Mackerel belong to the genus of fish called Scomber, and they are responsible for an ailment called scombroid poisoning, which is one of the reasons they have a reputation for spoiling quickly. If mackerel aren’t properly chilled, bacteria that are otherwise harmless can grow and release toxins. One of those toxins is histamine, which generates the symptoms of an allergic reaction.

Contact with histamine had probably caused Kate’s itching hands. Scombroid poisoning can occur with mackerel’s bigger cousins, the tuna, and is thought to be one of the most common forms of seafood-based food poisoning in the United States.

Sushi chefs divide all fish into three basic categories: red, white, and blue. Red is a narrow category, and tuna is the primary member. Swordfish also qualifies. Unlike most fish, these fish have blood-red meat. White includes fish with

pale flesh, including sea bream, snapper, flounder, and sea bass. Most fish in the ocean have pale, colorless flesh.

Blue refers to fish that have silvery-blue skin, such as mackerel. Blue includes fish that sushi chefs in Japan serve frequently but that Westerners encounter less often, suc...