In this guide

Every question in this article was asked by a real guest, standing at our counter, holding a half-shaped ball of sushi rice. “Why is this rice red?” “Is it true sushi used to be bigger?” “What does sushi even mean?”

Our cast writes these questions down after every class — and the same ones come back week after week. So here are the answers, properly researched, in one place.

Quick Answer: Edo-period sushi (early 1800s Tokyo) was street fast food: nigiri roughly twice today’s size, seasoned with reddish sake-lees vinegar called akazu, topped with cured or simmered fish rather than raw, and eaten by hand at open-air stalls. Refrigeration, refinement, and postwar rice rules gradually turned it into the smaller, cleaner, counter-served sushi you eat today.

Guests sharing handmade sushi around a communal table in a Japanese-style room — an echo of Edo’s shared street-food culture

Sushi Was Edo’s Fast Food

Nigiri sushi as we know it appeared in Edo — old Tokyo — in the early 1800s. The invention is most often credited to Hanaya Yohei, a sushi maker working near Ryōgoku, though like most food origin stories, several cooks were probably converging on the same idea at once.

What’s not in dispute is how it was eaten. Nigiri was street food, sold from open-air stalls called yatai. Edo was a city of busy laborers, craftsmen, and samurai on the move, and sushi was their quick lunch: stand at the stall, pick up a piece with your fingers, dip it in soy sauce, eat, go. No chopsticks, no reservation, no ceremony.

The story goes that regulars would wipe their fingers on the stall’s noren curtain on the way out — so a filthy noren was the sign of a well-loved shop. Take that one with a grain of salt, but it captures the spirit: sushi began about as far from a hushed omakase counter as food can get.

Why the Rice Was Red

If you’ve eaten at a traditional Edomae-style restaurant — or joined our class — you may have noticed the sushi rice isn’t pure white. It has a faint amber-red tint and a deeper, rounder flavor than typical sushi rice.

That color comes from akazu, red vinegar made from aged sake lees (the rice solids left over from sake brewing). As the lees mature over several years they darken, and the vinegar brewed from them turns a warm reddish brown, full of natural umami.

In the Edo period, akazu had two great virtues: it was cheaper than rice vinegar, because it was made from a brewing byproduct, and its built-in umami meant the rice needed less sugar and seasoning to taste complete. For a street food sold at workers’ prices, it was the obvious choice — red rice was simply what sushi looked like.

A sake toast over handmade sushi — akazu red vinegar is brewed from aged sake lees

Clear rice vinegar took over in the modern era, and white shari became the default image of sushi worldwide. But akazu never disappeared: many serious Edomae restaurants in Tokyo still use it, and a number have returned to it in recent years precisely because of that old-style depth. At our counter we season the rice with red vinegar too — which is why “why is the rice red?” is one of the most common questions in class. Now you know the answer before you arrive.

Why Sushi Used to Be Twice the Size

Edo-period nigiri was big — roughly twice the size of a modern piece, closer to a small onigiri rice ball than to today’s elegant two-bite nigiri. It was a meal, not a morsel: one or two pieces could keep a dock worker going all afternoon.

So why did it shrink? Two forces, one gradual and one very specific:

  1. Refinement. As sushi moved from street stalls to indoor counters through the late 1800s and early 1900s, it became less about filling up and more about tasting a progression of fish. Smaller pieces let a customer try more toppings — and they simply look more elegant. One popular explanation for why nigiri is often served in pairs is that shops began cutting the old oversized piece in two rather than reshaping it.

  2. The postwar rice rules. In 1947, under strict food controls, Tokyo sushi shops were allowed to reopen only as “processing services”: a customer brought their own rice — one gō, about 150 grams — and the shop exchanged it for ten pieces of nigiri. That ratio quietly standardized both the smaller piece size and the roughly-ten-piece set that still shapes sushi menus today.

We love this story because guests almost never expect it: the size of the sushi on your plate tonight was partly set by a rice-rationing rule from 1947.

What “Sushi” Actually Means

Here’s the surprise: the word sushi originally described a taste, not a dish. It comes from an old Japanese word for “sour.”

The earliest sushi, narezushi, wasn’t Edo fast food at all — it was a preservation method, likely arriving in Japan many centuries earlier along with rice farming. Fish was packed in salted, fermented rice for months; the rice was discarded and the pleasantly sour, preserved fish was eaten. (A direct descendant, funazushi, is still made around Lake Biwa today — it’s an acquired taste, to put it gently.)

That sourness is also why vinegar is the soul of sushi rice: when cooks stopped waiting months for fermentation and started adding vinegar directly, they were recreating that ancient sour flavor on demand. Edo nigiri was the final step — instant sushi for an impatient city.

The Japanese writing reflects this long history. You’ll see sushi written three ways: 鮓, the oldest character, referring to fermented fish; 鮨, an old character for a fish delicacy; and 寿司, the spelling most common today — chosen in the Edo era partly because the characters read as auspicious, roughly “governing long life.” A celebration food deserved a celebratory spelling.

The First Toppings Had Almost No Raw Fish

Ask people what defines sushi and most will say “raw fish.” Historically, that’s backwards.

Edo sushi stalls had no refrigeration, summer heat, and fish that had already traveled from the bay. So the original Edomae toppings — literally “in front of Edo,” from the bay at the city’s doorstep — were cured, marinated, simmered, or vinegared:

  • Zuke — tuna soaked in soy sauce, which slows spoilage and deepens flavor
  • Kohada — gizzard shad, salted and vinegared
  • Anago — sea eel, simmered soft and brushed with sweet sauce
  • Boiled shrimp and tamago (rolled omelet)

Wasabi earned its place in this world too: tucked between rice and topping, its pungency wasn’t just delicious — it has mild antimicrobial properties, genuinely useful for food sold outdoors in August. The placement survives today, long after refrigeration made it optional.

Fully raw nigiri — the glistening slice of untreated fish we now consider “classic” — is a modern development, only becoming standard once cold chains and refrigeration could guarantee safety. In a sense, the guests who ask us “how can Japan eat so much raw fish safely?” are asking the same question Edo cooks solved differently: they didn’t. They cured it.

(A related classroom question: searing fish over hot coals is an old technique, but the blowtorch-seared “aburi” style you see everywhere now is a recent fashion, not an Edo one.)

A couple with handmade nigiri sushi in a Japanese-style room at a Tokyo cooking class

Taste the History With Your Own Hands

Reading about akazu is one thing. Standing at a counter in Tokyo, shaping warm red-vinegar rice with your own hands while someone explains why it’s red — that tends to stick.

That’s what we do at Ramen Cooking Tokyo: a small-group class in Tsukishima where you hand-shape nigiri the traditional way (and make a bowl of Tokyo-style shoyu ramen from its broth up), with the history and trivia woven through the cooking. The questions in this article all came from guests standing exactly where you’d be standing.

“It was fun to learn about the history of sushi. I got to cut my boiled egg with a $6k knife!”

— Melissa, Google review (June 2026)

Frequently Asked Questions

Why is some sushi rice red?

Reddish sushi rice is seasoned with akazu, a red vinegar made from aged sake lees. In the Edo period it was cheaper than rice vinegar and rich in umami, so it became the standard seasoning for Edo-style sushi. Today most shops use clear rice vinegar, but traditional Edomae restaurants — and our class in Tokyo — still season the rice with red vinegar for its mellow, rounded flavor.

Why did sushi get smaller over time?

Edo-period nigiri was roughly twice the size of today’s pieces — closer to a small rice ball, filling street food for busy workers. Sizes gradually shrank as sushi moved indoors and became more refined, and after World War II, food-control rules that exchanged one go of customer-supplied rice for ten pieces helped standardize the smaller size served today.

What does the word sushi actually mean?

Sushi originally described a sour taste. The earliest form, narezushi, was fish preserved in fermented rice, and the sourness of that fermentation gave sushi its name. The dish is written several ways in Japanese: an old character for fermented fish, another meaning fish delicacy, and the popular spelling used today, which was chosen in the Edo era for its auspicious meaning.

Was sushi originally street food?

Yes. In the Edo period, nigiri sushi was fast food sold from open-air street stalls. Customers stood, picked up a piece or two with their fingers, dipped it in soy sauce, and moved on. Sushi only moved indoors to counters and restaurants later, and the price and formality rose with it.

What toppings did the first nigiri sushi use?

Almost nothing was served raw. Without refrigeration, Edo sushi masters cured, marinated, simmered, or vinegared everything: soy-marinated tuna, vinegared kohada, simmered anago, boiled shrimp, and rolled omelet. Serving fish completely raw on nigiri only became common in the modern era, once refrigeration made it safe.

Why is wasabi placed between the rice and the fish?

Wasabi was added to Edo-period nigiri partly for flavor and partly for hygiene: its pungent compounds slow microbial growth, which mattered when sushi was sold outdoors without refrigeration. The habit of tucking it between rice and topping survives today, long after the practical need faded.