The original sushi was not raw fish. It was preserved fish — packed in salt and rice and left to ferment for months or years, a technique for keeping a catch edible through a winter without refrigeration. The sushi the world knows, hand-pressed nigiri, was invented in Edo in the early 1800s as street-stall fast food. It is the last two centuries of a much longer story.
The clue has been in plain sight the whole time. The word sushi means “sour.” Not “raw fish,” not “rice” — sour. It is the old adjective sushi (酸し), preserved whole, like an insect in amber, in the name of a dish that mostly stopped being sour two hundred years ago. The name is a fossil of what sushi used to be — and in a handful of places in Japan, it is not a fossil at all. People are still making it, still eating it, and it still tastes the way the word says.
This is the story that connects the two: from a fermentation technique that arrived with rice farming itself, through a tax ledger from the year 927, to the counter you sat at last week.
The name tells you everything
“Sushi” means sour
In classical Japanese, sushi is the terminal form of the adjective 酸し — “sour,” “acidic.” The dish was named for its taste, and that taste came from lactic acid fermentation, not from vinegar. Everything else about sushi has changed; the name never caught up.
鮓, 鮨, 寿司: three ways to write one word
Japanese writes sushi with three different sets of characters, and the differences are a history lesson.
鮓 is generally considered the most original of the three: fish pickled in salt or lees, or preserved by packing it into fermented rice. If you want one character for what this article is about, it is this one.
鮨 came from China, where it is said to have originally meant something closer to a salted fish paste — a different preserved-fish product altogether. Over time the two characters were conflated in Japanese usage, and 鮨 became a standard way to write sushi. You will see it on the noren curtains of serious sushi restaurants today.
寿司 — the spelling everyone in the world recognizes — is the youngest by far. It is ateji, characters chosen for their sound rather than their meaning, dating to the late Edo period. The characters mean roughly “to administer longevity” (one account traces it instead to kotobuki no kotoba, words of celebration), which made it a lucky spelling for a celebratory food. So the way the entire planet writes sushi is a 19th-century piece of good-luck branding — a marketing decision, essentially, that outlived the marketers.
How narezushi works, and where it came from
Rice as a container, not an ingredient
The technique is called narezushi, and its logic is quietly brilliant. Gutted, salted fish is packed into cooked rice and weighted down under a lid, sealed away from air. Lactic acid bacteria feed on the rice’s starch and flood the container with acid, dropping the pH until spoilage organisms and pathogens cannot survive. The fish cures. Its proteins break down into amino acids — which is to say, into concentrated savoriness — and it keeps, in the strongest cases, for years.
Note what the rice is doing here: it is the machinery, not the meal. In original narezushi, the rice was a fermenting medium that was thrown away. For most of sushi’s history, the part everyone now considers essential was garbage.
The road it traveled
Narezushi is not a Japanese invention. The technique is generally traced to a belt of mainland Asia running from northern Thailand up through Yunnan in southwestern China, where fermenting freshwater fish in rice is an old and living tradition. It is thought to have reached Japan along roughly the same route as rice cultivation itself, which arrived from the continent around the Yayoi period. Rice farming and rice-fermented fish appear to have been part of the same package — which makes sense, since one is useless for the other without the first.
The oldest paperwork
Japan’s earliest solid documentation is bureaucratic, as the best historical evidence often is. The Engishiki, a compendium of laws and court procedures completed in 927, lists narezushi arriving from provinces across western Japan as chō — tax paid in goods. The taxed varieties included sweetfish (ayu), crucian carp, abalone, and even wild boar and deer. Fermented fish was valuable enough, and stable enough to travel, to serve as currency to the imperial court. Depending on the fish and the method, fermentation ran anywhere from a few days to several months, and in the longest cases into years.
The fork in the road: honnare and namanare
Here is the moment sushi changed, and it is smaller than you would expect.
The folklorist Osamu Shinoda proposed a distinction that still frames the discussion. Honnare is the original form: very long fermentation, the rice discarded, the fish eaten alone — a true preserved food, something you keep on a shelf against a bad month. Namanare ferments for a much shorter time, and — this is the crucial part — the rice bed is eaten too.
(It is worth noting that this framework has been questioned; the scholar Sakurai has argued that “namanare” described a difference in how a product was handled rather than a distinct manufacturing method. The categories remain a useful map, so long as you hold them loosely.)
Think about what eating the rice means. As long as the rice was thrown away, sushi was a preservation technique — a way of not starving. The moment people started eating the rice while it was still pleasantly sour, sushi became a dish. Someone decided the container tasted good. Every piece of sushi ever served since descends from that decision.
Funazushi: the living fossil
The most famous survivor of the honnare tradition is funazushi, made around Lake Biwa in Shiga Prefecture from nigorobuna, a crucian carp native to the lake. Roe-bearing females are salted for months, repacked in rice, weighted, and left — commonly for one to three years, sometimes longer. What emerges is sliced thin: dense amber flesh, bright orange roe, and an aroma that arrives well before the plate does.
Let us be honest about that aroma rather than coy. Funazushi is pungent in the way strong cheese is pungent — the comparison Japanese people themselves reach for. If your reference points are Roquefort, aged Époisses, or surströmming, you are in approximately the right neighborhood, and the taste is far less confrontational than the smell: deeply sour, salty, savory, with a long finish that goes remarkably well with sake. It is not a dare. It is a delicacy that costs a great deal and takes years to make, and the people around Lake Biwa have been eating it for something like a millennium. Treat it the way you would a first oyster: small piece, no expectations, second piece.
Regional fermented sushi still made today
Narezushi did not survive as a single dish but as a scattered family of local ones, each shaped by its river, its fish, and its winter. A rough map of what is still made:
Long-fermented, rice-only (honnare tradition)
- Funazushi — Shiga, crucian carp, the benchmark of the category
- Saba no narezushi — mackerel, made in Wakayama and Toyama
- Ayu no narezushi — sweetfish, made in Gifu and Hyōgo
Izushi (rice plus kōji mold) — a northern branch that adds rice kōji, giving a milder, sweeter, faster ferment
- Hatahata-zushi — Akita, made with sandfish
- Sake no izushi — Hokkaidō, made with salmon
- Kabura-zushi — Ishikawa, yellowtail layered into salted turnip
- Nezushi — Gifu
Related preserved-fish traditions
- Heshiko — Obama, Fukui: fish cured in salt and rice bran
- Ayu no kusaresushi — Utsunomiya, Tochigi: a namanare-style sweetfish sushi
- Iwashi no kusarizushi — Chiba, made with sardines
If you have eaten kabura-zushi in Kanazawa in winter and thought of it as a pickle, you were eating a direct descendant of the oldest sushi there is.
From fermentation to vinegar: the shortcut that made modern sushi
Hayazushi: skipping the wait
Fermentation is a superb technology with one serious flaw: it takes months. Somewhere along the way, cooks worked out that the sourness could simply be added. Season the rice with vinegar, and you get in an afternoon the flavor that fermentation took a year to build.
This is hayazushi — “fast sushi” — and it is the pivot on which the whole history turns. Vinegar is a shortcut through fermentation. The word sushi still meant “sour”; the sourness now came from a bottle. Osaka developed this line into pressed sushi (oshizushi) and boxed sushi (hakozushi), rice and fish compacted in wooden molds — a form that still tastes like a compromise between the old world and the new, in the best sense.
Nigiri: the fast food of Edo
Then, in the early 1800s, in Edo — a city of a million people, unusually full of single working men eating away from home — sushi became something you ate standing up. The stalls of Edo sold soba, tempura, and sushi to a population that wanted hot, fast, cheap food, and out of that market came nigiri: a hand-pressed finger of vinegared rice with a slice of fish on top, seasoned and often cured or marinated rather than truly raw, since there was no refrigeration. Its invention is usually credited to Hanaya Yohei, though it is generally accepted that no single inventor can be identified with certainty and that Yohei is better understood as the man who perfected and popularized it.
The point worth holding onto: the most refined food in Japan began as street food. Edo-mae sushi was fast, cheap, portable, and eaten with the fingers by workmen in a hurry. If you would like to see where that impulse ended up two centuries later, we wrote about it in our guide to conveyor belt sushi — a technology that returned sushi to exactly what it was in Edo: quick, affordable, and fun.
Eating your way into the old sushi
Regional fermented sushi is easier to try than most visitors assume. Station shops and michi-no-eki roadside stations in the relevant prefectures usually stock the local version; specialist producers sell online and ship; department store food halls carry the better-known kinds, especially around New Year, when several of these — kabura-zushi and izushi in particular — are traditional holiday foods. Some approachable entry points: kabura-zushi and hatahata-zushi are mild and genuinely delicious to almost everyone, while funazushi is the deep end. Buy the smallest quantity offered, drink sake with it, and eat it slowly.
None of this is meant to displace the sushi you already love. If anything, knowing the older story sharpens the modern one: the vinegar in the rice at a good counter is a thousand-year-old flavor arriving by express delivery. For the modern side of the family, we have guides to how to eat sushi properly — the etiquette questions everyone quietly worries about — and to temaki, the hand-rolled sushi Japanese families make at home, which is the least intimidating sushi on earth. And if the preserved-fish thread interests you, Japan’s other great river-fish tradition, unagi, tells a parallel story about how this country learned to make fish last.
FAQ
What is narezushi? Narezushi is the original form of sushi: fish salted and packed in cooked rice, then fermented under weight for months or years. Lactic acid from the fermenting rice preserves the fish. In the oldest form, the rice was discarded and only the fish was eaten.
Was sushi originally raw fish? No. Sushi began as fermented, preserved fish, and the raw-fish version is comparatively recent — nigiri sushi appeared in Edo in the early 1800s. Even then, toppings were often cured, marinated, or briefly cooked, since refrigeration did not exist.
Why is sushi called sushi? Because it was sour. The word comes from the classical Japanese adjective 酸し (sushi), meaning “sour” or “acidic,” describing the taste produced by lactic fermentation. The familiar spelling 寿司 is a late-Edo phonetic spelling chosen for its auspicious meaning.
Where can I try fermented sushi in Japan? Shiga Prefecture, around Lake Biwa, is the home of funazushi and the best place to try honnare-style sushi. Milder regional versions are widespread: kabura-zushi in Ishikawa, hatahata-zushi in Akita, izushi in Hokkaidō. Look in station shops, roadside stations, department store food halls, and specialist online shops.
