Sushi’s Epic Journey: From Slow-Fermented Fish to Global Fast Food

Vanishing Vestiges of Sushi’s Origins

The roots of sushi are usually traced to a type of slow-fermented fish known as narezushi.(*1) That ancient tradition still survives in the form of funazushi, a specialty of the area around Lake Biwa in Western Japan.

Funazushi is made from nigoro-buna, a freshwater fish native to Lake Biwa. The raw fish is salt-cured for several months, then pickled with cooked rice in an anaerobic environment for about a year. During the pickling, lacto-fermentation imparts a unique umami to the fish and tenderizes it to the point where it can be eaten bones and all.

Funazushi, a specialty of Shiga Prefecture, is freshwater fish that has been cured and fermented in rice through the action of lactic acid bacteria and other microorganisms.

Salted nigoro-buna are placed in a wooden barrel with cooked rice to ferment.

Mind you, fermented fish is an acquired taste. In fact, the uninitiated sometimes compare the smell to that of rotting garbage. But to foodies and locals accustomed to its distinctive odor, it is a top-tier delicacy. The perfect accompaniment to sake or other alcoholic beverages, it is also delicious when served on rice with some salted kelp and hot green tea to make ochazuke.

Funazushi is fairly well known in Japan, but how many people have actually tasted it? I once posed this question to my audience when delivering a lecture at a university near Lake Biwa. Out of several hundred students, only a few raised their hands.

Especially nowadays, with the proliferation of economical kaitenzushi (conveyor-belt sushi) chains, almost everyone in Japan has eaten sushi at one time or another. But the fermented ancestor of that beloved dish appears to be in danger of extinction.

The Southeast Asian Connection

Ironically, my immersion in Japanese food culture began in Southeast Asia.

Nearly 50 years ago, as a fledgling journalist covering the Cambodian civil war, I set up house in a rural community in Thailand. There was nothing available to eat but local products, so I consumed a lot of street food. While the tang of the fresh spices was new to me, there was also something comfortingly familiar about the aromas and flavors.

Intrigued by this mystery, I resolved to learn more about the local culture, starting with the food. With some local friends as my guides, I toured the area’s markets. They welcomed me into their kitchens and taught me how to cook their food. We ate it together.

The secret that revealed itself to me was the umami of fermented fish.

One key source of this umami is fish sauce, which is used as a basic seasoning agent in much of Southeast Asia: Thailand has its nam pla (fairly well known in Japan these days); Vietnam, its nuoc mam; southern China its yulu. Fermented fish sauce can also be found in certain regions of Japan—notably, the shottsuru of Akita Prefecture and the ishiri traditionally produced on the remote Notō Peninsula.

Another source of umami in Southeast Asian cuisine is fish paste made from salted, fermented seafood. This paste (for which there are many names) corresponds closely to the Japanese product known as shiokara, a salty and savory condiment made with squid or fish and their viscera. But while Japanese shiokara is typically nibbled as an accompaniment to alcohol, the Southeast Asian version is used as a seasoning.

I realized that the umami produced through fermentation was a feature common to Southeast Asian cuisine and the Japanese flavors I grew up with. This was what made the presumably exotic tastes of Thailand somehow nostalgic. I later learned that other neighboring countries share in this proclivity (for example, fermented fish paste is also used to season kimchi).

From Fish Sauce to Sushi?

Fish sauce like nam pla was originally a liquid byproduct of the fish-paste fermentation process, much as soy sauce originated with the liquid that collected (hence the term tamari) in fermenting miso.

So, how does this all relate to sushi?

It turns out that Thailand and Laos both have their own versions of narezushi—salted fish fermented in rice—which almost certainly preceded Japan’s funazushi. The Thai term is pla som, or “sour fish.” Like shiokara, narezushi originated as a means of preserving fish left over from a big catch. This method of preservation is thought to have originated in the interior of southeastern Asia, either in the area of northern Thailand and Laos or in southern China (possibly in the region of what is now Guizhou province). It was probably imported to ancient Japan from the Asian continent along with the technique of rice cultivation. References to preserved fish occur in some of Japan’s earliest written records, including the wooden tablets (mokkan) of the Nara period (710–94) and such Heian-period (794–1185) writings as the Engishiki (Procedures of the Engi Era) and the Konjaku monogatari (Anthology of Tales Old and New).

A Laotian version of narezushi, fish fermented in cooked rice.

Rice-fermented fish on display at a market in northeastern Thailand.

Nowadays, the funazushi found in the environs of Lake Biwa is practically the only vestige of this ancient tradition still extant in Japan. But at one time, narezushi seems to have been made all around the country using a variety of freshwater fish.

Sometime in the Azuchi-Momoyama period (1573–1600), quicker methods of preservation began to replace this technique. Sometimes the fish was fermented only briefly, in a technique referred to as nama-nare. Another means of preserving fish quickly was to pickle it in rice kōji (steamed rice on which a special mold has been cultivated). Izushi, still found in parts of Tōhoku and Hokkaidō, is an example of this technique.

Edo and the Birth of Nigirizushi

But how did all of this yield the dish we think of today when we hear the word sushi?

Although Japanese people have been eating raw fish, or sashimi, since ancient times, the pairing of sashimi with vinegared rice—what we call Edomae sushi—is a relatively recent phenomenon. Vinegared rice probably emerged as a quick substitute for rice made sour through lacto-fermentation. The marriage of vinegared rice and sashimi occurred sometime in the Edo period (1600–1868). The same era witnessed the spread of wasabi cultivation and the widespread production and consumption of soy sauce as we know it. In this way, all the basic components of modern-style sushi came together in the Edo period.

Nigirizushi (hand-molded seafood-topped sushi) was born in the city of Edo (modern-day Tokyo), and the term Edomae is still used to specify this style of sushi. Other regional versions developed as well, including chirashizushi (“scattered” sushi), oshizushi (pressed sushi), and inarizushi (sushi rice stuffed into sweet-and-savory fried-tōfu pouches). But hand-formed nigirizushi was for many years regarded as a quintessentially Edo dish.

In its early form, Edomae sushi was a bit different from the sushi familiar to most of us today. The seafood component was often either a simmered item, such as clams or eel, or a vinegared fish, such as cohada (a variety of shad). Raw tuna was popular, but it was generally served marinated in soy sauce—an option that appears as zuke on modern-day sushi menus.(*2)*

A boxed assortment of traditional Edomae sushi, which centers on seafood that has been flavored through simmering, pickling, or marinating.

Although popularized by Edo’s thriving street-food vendors (along with tempura and soba noodles), Edomae sushi was also served at high-end specialty shops catering to the well-heeled. The same dual-tiered structure that we see today—represented by widely accessible kaitenzushi on the one hand and pricey Ginza eateries on the other—seems to have existed almost from the start. (Incidentally, kaitenzushi debuted in Osaka in 1958 and spread nationwide in the wake of Osaka Expo 1970.)

From Edo Specialty to Pan-regional Favorite

Two historical developments helped accelerate the evolution of nigirizushi from a local Edo specialty into a nationwide favorite.

The first was the Great Kantō Earthquake of 1923. In the wake of that disaster, which destroyed much of the capital, many Tokyoites and Tokyo businesses relocated to other urban centers, taking the region’s food culture with them. The second was the food shortages and economic controls of the post–World War II years, when rice balls (onigiri) gained nationwide popularity as a convenient meal for people on the move, as well as a means of stretching limited rice supplies.

Of course, the dawn of modern refrigeration technology and the development of nationwide distribution networks were also key factors in the spread of Edomae sushi. With the advent of kaitenzushi and similar casual restaurants, sushi emerged as a pan-regional favorite. This development more or less coincided with the spread of fast food and family restaurants in the 1970s and 1980s.

Sushi Goes International

When I first visited the United States, in the 1970s, sushi shops were limited to places like Little Tokyo in Los Angeles and patronized mainly by Japanese and Japanese-Americans. Thailand also had a few sushi shops back when I lived there, but these, too, catered primarily to Japanese expatriates. They were places to treat one’s family or business associates.

All that began to change in the 1980s. It was an era when Japanese food was gaining Western adherents as the basis of a healthy diet. The California roll, made from raw salmon and avocado, was the popular “starter sushi” that got many Americans hooked.

Of course, some novices resisted the idea of consuming raw fish. But in many cases, they came to see that it was not so different, texturally speaking, from eating smoked salmon, oysters on the half-shell, or pickled herring. Further improvements in refrigeration technology and distribution helped, as did diligent efforts to export Japanese fish-processing know-how.

In this way, sushi has become an international food item, transcending the category of “Japanese cuisine.” It is a staple of the takeout sections of supermarkets and convenience stores all over Asia. I have seen it served as part of an in-flight meal on a South American airline and offered as a standard choice in non-Japanese restaurants in New Zealand.

In many cases, the overseas version differs little from the sushi we know in Japan, but in some instances the transformation is quite eye-opening—like the deep-fried sushi roll topped with jalapeno pepper cooked up by a certain Mexican chef . . .

Mexican-style fried sushi with jalapeno topping.

Let us resist the temptation to reject such deviations as heresy (as some critics in Japan are wont to do). The nation that developed mentaiko spaghetti (pasta in a sauce of spicy cod roe) and katsu karē (fried pork cutlets and Japanese-style curry on rice) has no right to pass such judgments. We should acknowledge that a dish can only join the ranks of “international cuisine” when it has transcended the food culture of its native country. But we can also take comfort in the fact that, amid this frenzied diversification, aficionados worldwide still make the pilgrimage to Ginza’s hallowed sushi shops, which continue to set the standard for true Edomae sushi.

(Originally published in Japanese. Banner photo: The California roll, which helped spearhead the internationalization of sushi. © Morieda Takashi.)