This is a transcript of the Gastropod episode Sushi’s Extraordinary Evolution: From Pickle to Primetime, first released on March 24, 2026. It is provided as a courtesy and may contain errors.

ERIC RATH: You find it in high-end restaurants, of course, but you can find it in Chinese restaurants, you can find it in supermarkets, in gas stations, in ballparks.

NANCY MATSUMOTO: And I was just in Mexico and at the Mexico City Airport, there’s this traditional sushi bar. Right there.

TREVOR CORSON: You can just find sushi in almost any location. High brow, low brow, you name it. It’s pretty incredible.

CYNTHIA GRABER: And everyone is eating it. My 12-year-old niece basically can’t get enough sushi, she’d eat it all the time if she could.

BROADCASTER: Parents are going broke from their kids’ sushi obsession! A Wall Street Journal article claims for some families, sushi has replaced pizza as the birthday party staple, and parents are paying a heavy price.

NICOLA TWILLEY: When I was a kid, I’d never heard of sushi! But today, it’s everywhere, and it’s everything.

RATH: Like sushi pizza, sushi burritos, you know, and on and on and on. So whatever you can do with this sandwich you can do with sushi. It is so flexible.

GRABER: But so, how did sushi take over the world? How did we get here?

TWILLEY: We got old, Cynthia, I hate to break it to you.

GRABER: Okay, but really, it wasn’t THAT that long ago that sushi was basically unknown in America. How did it become so popular that you can find it in the gas station?

TWILLEY: Well, and while we’re talking about ancient history, it’s not *that* that long ago that sushi didn’t even mean raw fish on top of white rice. So how did sushi go from being a Chinese pickle to the California roll we know and love today?

GRABER: And what does all this have to do with World War II, the movie the Breakfast Club, and our recurring favorite, microbes?

TWILLEY: Drink! This episode is supported in part by the Alfred P. Sloan Foundation for the Public Understanding of Science Technology and Economics. Gastropod is part of the Vox Media Podcast Network, in partnership with Eater.

[BREAK]

CORSON: Well, to understand the history of sushi and the earliest form of it, you have to completely reverse your entire understanding of sushi. Today, sushi is all about the rice.

GRABER: Trevor Corson is the author of the book The Story of Sushi. But once upon a time, you didn’t need rice at all to call your dish sushi.

TWILLEY: Eric Rath is the author of Oishii: The History of Sushi, and he tracked down the earliest sushi recipe in a Chinese book called The Important Arts for the People’s Welfare, compiled sometime in the mid-500s.

RATH: And it tells you how sushi is made. And in this context, sushi is fermented. And basically, a freshwater fish is cleaned. It’s salted. It’s put away for a while, so the salt does its work, getting the moisture out of the fish. And then the salt is washed away and it’s packed with some kind of grain, and it doesn’t necessarily have to be rice. It can be some kind of millet. And six, eight, 12 months later, it’s unsealed.

GRABER: This earliest recipe for sushi is nothing like we’d eat today. This is fish fermented for a year by lactic acid fermentation, like you’d use to make yoghurt, pickles, kimchi. The microbes for those can feed on the sugars in the vegetables or the milk. But fish has almost no sugar—so in this case, the millet or rice feeds the microbes that create acids that then ferment the fish.

TWILLEY: Basically, it’s a clever technique to preserve protein. Before refrigeration, you could smoke or salt fish to stop microbes growing on it, but this grain-based lactic acid preservation works by recruiting friendly microbes to keep the bad guys out. And in the process it creates a whole new flavor explosion.

CORSON: And that original version of it, the fish was a, a kind of fermented fish that is sort of similar in some ways to cheese. It was kind of fermented with a lot of esters and acids and flavor compounds from the fermentation process. So it probably tasted like a cheesy [LAUGH] aged fish.

GRABER: Cheesy is not a description I look for when it comes to fish. Eric’s tried this kind of long-fermented sushi—it’s rare to find it today, but a few people still make it.

RATH: There are modern versions of this in Japan and it’s remarkable. Because the taste profile becomes something like a prosciutto, or a summer sausage. And it’s all due to lactic acid fermentation. This same fermentation that’s used in yogurt is used in this type of sushi. And it gives it a sour taste, but it also gives it this meaty flavor, which is incredible.

TWILLEY: Eric says in ancient China, people often used this savory, sour pickled fish to add to soups and other simmered dishes, just as a little burst of flavor.

RATH: You don’t want to eat a lot of it. I made that mistake once. [LAUGH] And my mouth tasted like bile, because it was so salty. But, if you just—a little, select amount, with a little sake, it’s very nice.

GRABER: So that’s the fish, but there’s also grain in the recipe. The Chinese used both millet and rice to help preserve the fish, but whichever one they used, it wouldn’t have been edible at the end of the process.

RATH: The grain, the rice becomes kind of a mush. And it’s so salty and so sour, that it’ll turn your head around. So most people don’t eat the rice. They just eat the fish.

TWILLEY: No one knows exactly where this technique of using a grain to ferment fish got started, it probably emerged multiple different places and times in southeast and east Asia. In delta regions, rice farming and freshwater fish went hand in hand, so using one to preserve the other would make sense.

GRABER: But in any case, it was big in China, and that’s where both the earliest written sushi recipes in the world are found and also Chinese characters that are related to the word sushi were used.

CORSON: We don’t know its exact origins. But the ‘shi’ part may have come from a Chinese word that referred to preserved fish.

TWILLEY: So you may be thinking, wait a minute, if sushi was so big in China back in the day, why is it not today? We don’t think of sushi as Chinese. Eric says it was popular through the 1700s, but then, for a variety of reasons, people started preserving their fish differently and sushi just dropped off the map there.

RATH: And in Japan it becomes a dish all in on its own.

GRABER: Eric says the first reference in Japan was in the 700s, and it does seem to have spread there from China. The Japanese likely adopted the shi sound from China and then added their own descriptor.

Trevor: The ‘su’ part comes from the, probably the word sour in Japanese. So sour preserved fish.

TWILLEY: Or su-shi, but not as we know it today!

GRABER: Like in China, the Japanese were sometimes using millet, and sometimes using rice, but also they weren’t always using fish as the protein.

RATH: They made sushi out of abalone. They made it out of freshwater fish. But, mountainous areas, they made sushi out of wild boar, and deer. So there was meat sushi back then as well.

TWILLEY: In medieval times, after a few hundred years of enjoying this slow-fermented cheesy preserved fish or meat, Japanese people lost their patience.

RATH: People just got tired of waiting around for a year to eat their sushi. So rather than wait the full time, they would eat it sooner. And in that case the rice is not as… not as sour. It’s a little more agreeable. It’s got a little more body to it.

GRABER: Which was a great thing, because rice in particular was expensive and it had a lot of calories. Why throw it away if you didn’t have to?

RATH: But still. Why wait weeks when you want to eat sushi? So in the 18th century, 17th, 18th century, people start experimenting with how do we make sushi faster? Let’s add vinegar. And so rather than this long period of, of fermentation, that transformed the rice, changed the taste. You just add the vinegar to the rice, with some salt…

TWILLEY: Vinegared sushi was still sour, though not nearly as sour as the original, and the fish isn’t preserved the same way. It wasn’t raw though, it was still lightly pickled, and typically also cooked somehow.

GRABER: These transformations were being made in Edo—this is what’s now Tokyo—and it became first the military and administrative capital of Japan in the 1600s and then it became the actual capital in the 1800s, and people there loved their quick-fix sushi.

MATSUMOTO: So the story is that these vendors would be selling Edomae sushi. And it was meant to be a portable little, like a pocket thing. That you could just carry in your hand and eat really casually.

TWILLEY: Nancy Matsumoto is a food writer, her latest book is Reaping What She Sows: How Women Are Rebuilding Our Broken Food System. She’s also written extensively about sake and Japanese cuisine.

MATSUMOTO: So ‘mae’ means in front of. Apparently it was along Tokyo Bay, it was in front of the sprawling city of Edo that you would find these push cart vendors. And, it was really kind of like street food of the day. So very casual, but a way to have a quick, portable lunch.

TWILLEY: Nancy told us that sushi was not at all fancy back then.

MATSUMOTO: Now, you know, it’s so expensive. We think of it as like, it must have always been rarefied, but I think it’s kind of humble in its origins.

GRABER: Edo is also where nigiri was invented. Before, sushi wasn’t necessarily a piece of fish pressed on a handful of rice. You might have just eaten the fish, you might have scooped up the rice.

TWILLEY: But in Edo, people needed something handheld so they could eat on the go. And so in the 1700s, someone, no one knows who, figured out that if you pressed a slice of fish on top of a slightly flattened cylinder of rice, and squeezed it together with some condiments, the resulting nigiri sushi was the perfect street food, kind of a like a hot dog.

RATH: And indeed the size of the sushi is about the size of a hot dog. And even into the 1920s, 1930s, people who want good sushi go to a place where you’d stand and eat, like a hot dog stand today in the United States. So it’s street food. It’s quick, grab and go. Kind of meal.

GRABER: So sushi changed form in Edo, and it also changed ingredients. Edo was located on a saltwater bay, and there were lots of fresh ocean fish available.

RATH: And so people begin using those rather than river fish. And somewhere along the way they also decided that deer and wild boar don’t make good sushi either.

TWILLEY: So Edo-style sushi became associated with fish rather than meat. The other kind of sushi that was invented in this golden age of sushi innovation is the roll, or maki.

RATH: Now in Japan, when these were invented in the 19th century, they’re very simple. We just have a geometric, tubular shape with rice, and something like cucumber or… gourd inside, pickled gourd.

GRABER: In some super early rolls, people used actual paper for the roll’s wrapper, and they couldn’t eat it. But then someone had a brilliant idea about how to create a paper that you could eat.

RATH: Right around the same time, early 19th century. someone saw what they were doing with paper making in Japan and applied that to nori, the seaweed. And you can get a nice flat sheet of that. And you can roll things up in it.

TWILLEY: Such as sushi!

RATH: And then you could take your rice, and whatever you wanted to put inside. And people sometimes made thick rolls too. But generally it’s very slim, trim kind of thing, of cucumber or this preserved gourd that I mentioned earlier. Maybe some egg in there.

GRABER: And the mats they used to roll those rolls? They are made of bamboo and look like window shades, which is apparently what they were modeled after.

TWILLEY: So in the 1700s and 1800s in Edo slash Tokyo, sushi was completely transformed. It went from a method of preserving freshwater fish and meat that took months to make—to something that was made to order, using fish from the ocean. And it also went from a kind of pickle format that you ate alongside or in other things, into a fully-fledged, handheld snack.

GRABER: But as popular as sushi was in Tokyo, which is what Edo became in 1868, all these rolls and the nigiri and all this street food, it was really ONLY super popular in Tokyo. There was a survey done by Japanese ethnologists in 1941 where they were looking into popular traditions in rural Japan.

RATH: And they asked them, you know, what kind of sushi do you make? And a lot of folks didn’t know what sushi was. Which I found astounding.

TWILLEY: In the early 1900s, in more rural areas of Japan, some people were still making the traditional fermented kind of sushi, using meat and vegetables. They were using dried gourds, and taro stalks, and carp from the rivers, whatever was local.

RATH: They didn’t know the forms of sushi that we know today. The nigirizushi. The sushi roll, the makizushi.

GRABER: Then there was a huge earthquake in 1923 that led to major fires that basically burned Tokyo down, and then the city was bombed in World War II. And so a lot of people living in Tokyo fled to their home regions. This included people who wanted to eat sushi and people who knew how to make it. So after the war, in the late 40s and onward, Tokyo-style sushi became THE style of sushi.

TWILLEY: The other thing that happened was wait for it, my favorite topic, refrigeration! First with ice, then mechanical—and what that meant was people didn’t have to rely on lacto-fermenting their fish anymore to preserve it. So a lot of those rural styles just died out.

GRABER: Ice was great, and it was even more useful on brand new long-range ocean trawlers. These innovations together also meant that the fish used to make sushi was transformed again.

RATH: With this flash freezing technology on these huge trawlers, they’re able to go beyond Japan’s waters, really globally to source fish. So that is a huge change.

GRABER: This is part of the reason for the rise of bluefin tuna in sushi—we have that story in our episode All Aboard the Tuna Rollercoaster. You should check it out.

TWILLEY: Another huge change came about because of wartime rationing. Like we said, before the war, a piece of sushi was the size of a hot dog; during and after, it shrunk down to the bite-size piece of rice and fish we know today.

GRABER: Before the war, you would have eaten your sushi at an outdoor stand. But during the war, the government shut down those stands because they were considered a health hazard. So after the war, sushi moved indoors into restaurants—where even more innovations took place.

RATH: You have the inventions like conveyor belt sushi. Where this man in Osaka, he had a standup sushi restaurant and he thought, you know, how can I best present my dishes to the customers? And excite them to order more? Well, he visited either a meat packing plant or a beer brewery and saw the conveyor belts and put two and two together, and came up with this idea of conveyor belt sushi. And initially people stood in those restaurants, until he decided to allow them to sit down ’cause they would eat more.

TWILLEY: This conveyor belt genius was a guy called Shiraishi Yoshiaki, and he transformed his sushi restaurant, Genroku, into the world’s first conveyor belt restaurant in 1958. And people loved it, especially families and young people—they found it way more welcoming and fun than the old school snack stands.

MATSUMOTO: Oh, it’s amazing. It’s like being on an auto assembly line, except sushi is going by, not car parts. And, yeah. Basically it’s, you know, little plates of sushi with plastic covers are going by. And then you’re—you tally up your plates, and they give you your bill based on the plates and the colors of the plates.

GRABER: Mr Yoshiaki eventually opened about 250 restaurants. And though his chain faded out, plenty of competitors launched their own versions, and the conveyor belt sushi restaurant itself is still going strong.

MATSUMOTO: They’re all over Japan, and there are chains of them that are really popular. And unbelievably inexpensive too.

TWILLEY: But at the same time, as Japan got wealthier, especially in the economic boom of the 1980s, an extremely ritzy version of this former street snack also emerged.

MATSUMOTO:At the time Japan was so economically powerful. And people really had a lot of new wealth. So, people would be spending on these high-end sushi bars. And I think that’s probably where a lot of this lavishness that you see now probably evolved.

GRABER: But how did this raw fish on rice that you might spend a week’s salary on, how did that conquer America as well? That story, after the break.

[BREAK]

TWILLEY: One of the earliest records of sushi in America comes from a Los Angeles newspaper in the early 1900s, when a socialite in LA served it to make a splash at a fancy luncheon. But there were also reports at the time of sushi being served as far afield as North Dakota. There were Japanese immigrants to the US at the time and Westerners had also started traveling to Japan more often after the country had opened up to foreigners in the late 1800s.

GRABER: But then fewer Japanese immigrated to America after 1907, when the US and Japan made an informal agreement: Japan wouldn’t send more immigrants our way, and America wouldn’t impose restrictions on immigrants, like segregating Japanese children in different schools.

TWILLEY: And then the relationship got even worse.

RATH: The landscape completely changed during wartime, of course. And then it’s not until the 1960s where in the same area in Los Angeles and on the West coast, sushi takes off again.

TWILLEY: When Nancy was a kid in LA in the 1960s, sushi wasn’t something you really found in restaurants. She had it at home, often for New Years’, her grandma would make a whole spread of special foods.

MATSUMOTO: And the kind she made was called Futo Maki, which means literally, fat roll. The Futomaki has- kind of has it all. It has the tamagoyaki, the omelet. She would do marinated and cooked shiitake mushrooms. She did this thing called oboro, which would be, probably was fresh fish in Japan, but in America, she would get canned shrimp. And sort of grind it into sort of a meal.

GRABER: Oboro is a dish of minced fish—Nancy’s grandma used canned shrimp—and she put some greens in her fat rolls, too. These weren’t just for New Year’s, she’d make sushi for a lot of the major holidays.

MATSUMOTO: I remember telling a friend that whenever we celebrated Thanksgiving, we always had turkey and we always had sushi. And he thought it was very weird. And I—it was only then that I thought, oh, maybe that is kind of weird. But to me it was just normal.

TWILLEY: It would have been weird for most non Japanese Americans. Because like we said, sushi wasn’t really available in restaurants. The first sushi bar in the continental US that served Tokyo style sushi seems to have opened in 1965, in LA’s Little Tokyo area. It was called Kawafuku.

GRABER: There was apparently sushi available in Hawaii earlier, and Japanese restaurants in LA had previously served tofu pockets stuffed with sushi rice, but this was something different.

CORSON: That was a kind of deliberate effort to start a sushi trade in the United States by business people.

MATSUMOTO: One was a manager for mutual trading, and another was an entrepreneur.

GRABER: Mutual Trading was the largest importer of Japanese food, drinks, ingredients, equipment: everything you’d need to make Japanese cuisine. It’s still around today.

MATSUMOTO: And this was back in like the mid sixties. The Japanese fellow took the American to a fancy sushi bar in Tokyo and he fell in love. And they decided, because Mutual Trading is a huge import company, that they could bring in everything needed for a sushi culture. So kind of like importing it wholesale, all the different parts of it.

CORSON: But it didn’t really catch on outside of the Japanese community at first. Japanese businessmen started to bring their American colleagues, so there were a few people who started trying it.

TWILLEY: Some of these people fell in love with sushi, but It was an uphill struggle. Because at the time, if you asked a non Japanese American what Japanese food was, they probably wouldn’t have even mentioned sushi. Here’s a clip from a scene set in 1969, it’s from the movie Zodiac, and two cops are talking in a car, they’re snacking on animal crackers.

COP 2: You ever try Japanese food?

COP 1: What do you mean, like teriyaki?

COP 2: No, like the urchin, raw fish.

COP 1: I’m eating here, Bill.

GRABER: Teriyaki is meat, usually chicken or beef, it’s brushed in a salty sweet sauce that includes soy sauce, then it’s grilled or pan fried.

RATH: And that’s something that would be a more familiar dish to white Americans. That’s synonymous with Japanese food. It’s not sushi at all.

CORSON: It wasn’t really until around 1970 that a sushi bar opened closer to Beverly Hills, and that’s when Hollywood celebrities discovered sushi and started eating it. Yul Brynner was famously one of the early fans of sushi and helped popularize it.

RATH: John Belushi, the Samurai, whatever, you know, on Saturday Night Live. And. Apparently he was a big sushi fan.

MAN: Like a room for the night, please.

SAMURAI: [FAKE JAPANESE]

CORSON: And once it became kind of a Hollywood thing, the Hollywood celebrities all started eating it. And then there was suddenly demand for sushi restaurants in LA. And a and a bunch of Japanese chefs realized they could come and do business in, in LA with celebrities.

GRABER: And once the celebrities were into sushi, other people mostly in the bigger cities wanted to do what the celebrities were doing, and so sushi restaurants started to open on both coasts.

TWILLEY: Back in the early ‘60s, when New York Times restaurant critic Craig Claiborne mentioned sushi in an article, he said it was quote “too far out” for most New York diners. A decade later, Manhattan was full of sushi restaurants and Claiborne said that New Yorkers were quote, “dining on raw fish with a gusto previously reserved for cornflakes.”

GRABER: And then a bunch of things happened that helped propel sushi further into the limelight. There was a big-deal government report about the American diet in 1979, and as one of their recommendations, they suggested eating more fish, like all the fish you’d find at a sushi restaurant.

RATH: But it’s not until the 1980s where it really takes off and sushi goes full blast into US culture. And that’s exactly the time too, that the Japanese economy and, and trade with the United States is taking off as well. And we have shows like Shogun on TV.

[SHOGUN THEME MUSIC]

CORSON: Richard Chamberlain played a British ship captain who went to Japan in the 1600s. And it was all about the life of the Shogun warriors. It was an enormous hit. It was one of the most popular TV shows in NBC’s history.

TWILLEY: Literally one-third of Americans watched this show, it was a huge cultural moment.

CORSON: And that also really created a groundwork for interest in all things Japanese in the United States, which helped make sushi become more popular too.

GRABER: And another thing that made sushi cool was that during the same time, as we said, Japan had become an economic powerhouse. The country had been broke after its defeat in World War II, but then its economy grew, a lot through electronics. And Japanese companies like the one that invented the walkman, Sony, these companies and their products became huge all around the world.

RATH: And Japan is booming in this period. This is a time where the popular magazines were showing images of Japan Incorporated taking over, you know. Giant sumo wrestlers, grabbing buildings in New York City.

TWILLEY: And as Japanese companies were taking over wall street and Japanese products were taking over America, suddenly there were sushi references everywhere in popular culture too. Like in the 1984 cult classic movie Repo Man.

MAN: Oh, dear. What a shame.

WOMAN: Come on, Duke. Let’s go do those crimes!

DUKE: Yeah! Yeah! Let’s go get sushi and—and not pay!

MATSUMOTO: It’s just this very, surreal kind of offbeat movie. So to me that was like, when it was cool. It was kind of new and it was like—if you were hipster, that’s what you would do, is like, let’s go get sushi.

TWILLEY: Except you probably had to pay.

GRABER: Right, And you might have had to pay a lot, because at the time in America sushi was still pretty expensive. So while it may have been cool, if you were eating sushi, you probably had some money.

CORSON: You could be exotic, and kind of show off that you were doing something no one else was doing. That you were brave, that you knew something, you were in the know, you were ahead of the curve. So sushi definitely had cachet in that sense.

RATH: So it’s, it’s a, it’s a sort of connoisseurship. A way of, of promoting your, your knowledge and status. That you could not only afford sushi, but knew how to order it. And it’s a part of the cliche of sushi, is understanding that culture. And that’s why it appeals to yuppies. You know, people who saw themselves as in the know knew how to negotiate a sushi bar.

TWILLEY: Both Trevor and Eric tried sushi for the first time in the 1980s

RATH: I remember, first time I ordered sushi in a restaurant. You know, my friend and I, we saw the movie, the Breakfast Club…

[DON’T YOU FORGET ABOUT ME]

RATH: …and saw Molly Ringwald bring it in her lunch…

JOHN: What’s that?

CLAIRE: Sushi.

JOHN: Sushi?

CLAIRE: Rice, uh, raw fish and seaweed.

JOHN: You won’t accept a guy’s tongue in your mouth and you’re going to eat that?

CLAIRE: Can I eat?

RATH: And we go, we’ve got to go eat sushi! You know? And so as high school students, we went to a restaurant and we sat down and ordered it. And, this beautiful plate appears in front of us. And we didn’t know what the heck to do. You know? [LAUGHING] Like there’s no fork. What, how do we eat this?

TWILLEY: The waiter kindly showed them how.

RATH: Yeah, it was, it was like magic after that. But initially… [LAUGH] we were scared to death. I think that’s why we went together. And two guys, because we didn’t want to embarrass ourselves in front of girls.

GRABER: Over the decades more and more people kept trying sushi, and more and more sushi restaurants opened, it got cheaper, and really it seemed like almost all Americans fell in love with sushi. Which is surprising, because it’s raw fish, and there’s not a lot of raw meat or fish in general in the standard American diet.

CORSON: There’s, there’s a kind of interesting contradiction with sushi. Which is that on the surface it seems extremely exotic. Like raw fish seems really gross. However, once you start thinking a little bit more deeply about what sushi is, what the ingredients are, it’s actually not so much of a stretch. So I think originally people might’ve been repulsed by the idea of eating raw fish, but actually, the flavor components in sushi—rice seasoned with vinegar, sugar, and salt—it’s basically sweet and sour rice. Which is delicious. So. In fact, once you get over the kind of psychological barrier of the fish being raw, and you realize it’s not dangerous to actually eat it. When you actually do eat it, suddenly the tastes are actually so welcoming that it’s not hard to cross over into suddenly becoming a sushi fan.

TWILLEY: That’s nigiri, but sushi rolls were a little bit more of a challenge for non-Japanese Americans.

CORSON: Yeah. There was one aspect of sushi that did strike people as really freaky in the United States, which was like, the idea of eating black paper made of seaweed. And so the sushi roll with the nori seaweed paper on the outside was, was a, a difficult one for, for Americans to, to get used to.

GRABER: There’s this idea that that’s why the California roll was invented. The California roll has crab, often artificial crab, and avocado and cucumber in it, and the rice is outside the nori, the seaweed. A lot of people think that it was invented for Americans, but the story is actually that it was originally invented for Japanese customers in Los Angeles.

CORSON: Because it was really hard to get fatty tuna belly. So chefs there experimented with substitutes, and the best one they came up with was mixing crab meat with avocado. It created this kind of similar, fatty, melt in your mouth sensation as tuna belly. So they started making roll with crab meat and avocado. And that was the first key innovation, to creating the California roll.

TWILLEY: So the filling was developed for Japanese palates, but the idea of flipping the seaweed and the rice so the rice was on the outside, that does seem to have been done to make the roll less intimidating for non-Japanese Americans.

CORSON: So Americans wouldn’t look at this black seaweed paper and get freaked out. So it was the combination of those two developments that created the California roll. And, and then once it was flipped inside out, then it was much more accessible for American diners and, and spread quickly.

GRABER: The super popular spicy tuna roll was also invented here. Spicy rolls weren’t a thing in Japan, but Americans love spicy food, and the spice was a great way to cover up what wasn’t the best, most beautiful slice of raw tuna belly.

CORSON: Like, all the shavings that are left over—after you take a tuna fish and clean it up, there’s a bunch of gunky, you know, flesh left in the skin and stuff. And they would just scrape that all out with a spoon and chop it up and mix it with hot sauce and put it in a sushi roll. And that was the invention of the spicy tuna roll. It was basically just a way to profit off the scraps that you couldn’t sell otherwise.

TWILLEY: All of this—the new rolls, the celebrities, the TV shows, the affordability—it all added together to help sushi become wildly popular in the US, as well as in Europe a little later. But some things have got lost in translation. There are some aspects of the art of sushi that we are missing out on over here. Those are coming up, after the break.

[BREAK]

GRABER: At the beginning of the sushi wave in America, in the early 60s, most of the people who were opening the first sushi bars were traditionally trained chefs and the restaurants were super high quality.

CORSON: And that’s where the Hollywood celebrities started to go. But once it became more of a trend, you had a wave of sushi chefs who didn’t necessarily have such extensive training. Because these were the people who didn’t want to stay in Japan, ’cause they were frustrated how long the apprenticeships were to become a sushi chef in Japan. It was a very traditional culture.

TWILLEY: This traditional training was actually a post-war innovation: before the war, when sushi was a snack, there was no formal rigid training. After the war, when sushi became a restaurant food, that’s when the Japanese started this whole loooong apprenticeship thing.

CORSON: You would have to just like wash dishes and learn to make rice for, you know, three years before you were allowed to start cutting fish. And it’s a very, very slow hierarchy to get through. And suddenly, you could say, well, I’m going to go to America and open my own sushi restaurant.

TWILLEY: The people who said that were often more like entrepreneurs than chefs, and they weren’t necessarily that obsessed with quality.

CORSON: And so through the 1980s, you had the creation of this whole kind of culture of all you can eat, you know, inexpensive, low-brow sushi spreading through California and other parts of the US. And that’s continued. It’s not necessarily a bad thing in the sense that it’s a, it’s an easy to eat, convenient snack food. But. Yeah, you didn’t, you didn’t have the knowledge and appreciation generally in the culture for what the more authentic sushi experience was supposed to be.

GRABER: And so some schools sprouted up in the US to teach people how to make sushi, how to make excellent sushi, but without having to spend years and years training in Japan. Trevor shadowed a bunch of students at one of those schools for his book, the Story of Sushi. He didn’t go through the whole training himself, but he did try to get a taste of what the students were learning.

CORSON: There were some classes that they offered on weekends for just everyday people to come in and try some basic sushi making stuff. And I did try those, and I was immediately extremely humbled. And I think it’s really good that I did that. It was just really basic stuff, like how to make a California roll or how to make a nigiri. But it was so hard.

TWILLEY: One of the things Trevor learned, which is kind of weird for something that most of us associate primarily with raw fish, but learning how to make sushi right starts with rice, because rice is the only truly essential component.

GRABER: Which is ironic because rice used to be the part that was thrown away, back when sushi was still just fermented fish.

CORSON: So what defines sushi today is, is rice that is sour. So today it’s made with vinegar, and pretty much anything with vinegared rice can be called sushi. And it is the number one first skill that every sushi chef has to learn is how to deal with rice, how to cook it, how to prepare it properly, and season it properly, and keep it properly and, and all this.

GRABER: This took the students at the school a while to get right. It’s much harder than it seems—which does make me feel a little better about how when I try to make sushi rice at home, it doesn’t come out anything like the rice in the restaurants.

CORSON: It’s really like a martial art, almost, the way that they do this. It takes lots of practice. And they’re able to create these perfect little rice packets that, that mingle with the fish in your mouth. And most of us never experience this, unless we go to a high-end sushi bar and do everything right.

GRABER: We’ll get back to what Trevor means by ‘do everything right’ but back to the chefs, and the rice they’re learning how to master.

TWILLEY: Right because the other thing that matters is the type of rice. There are two main types of rice in the world: non-sticky, which is the most common kind, and sticky. For sushi, you have to use the sticky varieties.

CORSON: What makes them unique is that the carbohydrates inside the rice are, are all disorganized. Most rice, the carbohydrates are kind of well-organized into little packets inside the rice. And in sushi rice, they’re not. And that makes them… all jutty, if you looked at it with a microscope, you could see that things are all sticky on the outside. And that’s what makes the rice stick together enough, with the other grains, so that sushi chefs can even do this.

GRABER: So before they even touch fish, sushi students learn about rice, and they learn a lot about knives, because sushi chefs are obsessed with their knives, which are super sharp, they’re perfect for carving these beautiful nearly translucent slices of fish and peeling cucumbers into super thin sticks.

TWILLEY: And it turns out that these knives have quite a pedigree.

CORSON: As the samurai warriors were becoming too dangerous, samurai swords at one point were outlawed. And so all the samurai sword makers turned their attention to—and their skills to making kitchen knives instead. So what you’ve got in a sushi chef’s knife is, is actually, literally, the direct descendant of a samurai sword. And it’s made with high carbon steel through an exhaustive process of folding and, and smoothing. And they have to be hand sharpened, on volcanic stone, every day.

TWILLEY: Rice, knives, And then finally, the fish. The students had to learn how to de-scale and cut and prepare a whole variety of fish, all of which have to be handled differently. Honestly, it sounded grueling.

GRABER: The most grueling thing most of us have to do at a sushi restaurant is decide what to order. There are plenty of things on the menu, and some of them aren’t even sushi.

CORSON: Today? Yeah. Sushi has to include rice to be called sushi, I think. Sashimi, the slices of raw fish that you get at a sushi bar, is actually a completely different culinary tradition from sushi. It predates sushi, and it wasn’t necessarily just fish.

GRABER: Neither was sushi, of course, but the point is that sushi was originally about preserving fish or meat. And sashimi was always really about enjoying the food raw.

CORSON: The nobles in old Kyoto would, would eat raw meat of wild boar, deer, crane as well as as fish. So that sashimi raw meat is separate culinary tradition.

TWILLEY: Unlike sashimi, sushi doesn’t have to be raw, even today.

CORSON: No, sushi does not at all have to be made with raw fish. And in fact, this is a relatively recent development, having raw fish being so central to sushi. Pretty much every sushi ingredient served in sushi, go back to the 1800s, would’ve been somehow preserved or fermented. And, and not particularly raw in the sense of being straight out of the ocean or anything. And there’s plenty of vegetables that have entered into the sushi ingredients list, of course, as well.

GRABER: And even the fish that you are eating raw, it basically isn’t fresh out of the water, and that’s actually a good thing.

RATH: Here’s the, the, the secret. Is that if you order sushi in the United States at least, and it’s not a fish that you caught, if you order it in a restaurant. That fish has been frozen for a long time. At a low, low temperature. And they do that to get rid of the parasites.

TWILLEY: So is frozen still fresh? Well, it turns out the word fresh is entirely meaningless and if you want to know why, I have a book I can suggest, namely my own.

GRABER: But then okay so sushi is rice-based, it can be fish or vegetables, the fish isn’t necessarily raw. So how about all the things that really don’t seem like sushi? Like hamburger sushi, sushi burritos, or all the unusual flavors that people put on rolls. Like mango puree or spicy mayo with sriracha in it.

CORSON: It’s easy to kind of feel snobby about all these crazy American rolls. You know, [LAUGHING] cream cheese roll and Thanksgiving roll with turkey and cranberry sauce inside. But if you look at the history of sushi, it’s been constantly changing. All kinds of different ingredients have been tried in Japan in sushi over the decades and centuries. So I came to the view that there really is no such thing as “authentic” sushi. I use the word authenticity when I talk about sushi in relation to the kind of really nice traditional Tokyo style sushi bar experience. But in fact, almost any kind of topping or ingredient can still be called sushi, in my view, after having researched this as much as I have.

TWILLEY: Trevor may be pretty open minded when it comes to what ingredients can be combined and still called sushi. But he does have issues with the way many Americans eat their sushi. For one, those of you who take your wasabi and stir it into your soy sauce? Trevor wants to have a word.

CORSON: There’s a couple of problems with using it this way. One is if you actually mix it with liquid, the potency of the wasabi is dramatically reduced, so it’s kind of pointless to mix it in the soy sauce I learned. And then the other thing is that it really overpowers and overwhelms the flavor of the fish so much that you’re missing out completely on the fish.

GRABER: He suggests either ignoring the wasabi entirely or dabbing a tiny bit on the end of a piece of sashimi. Eric agrees that you shouldn’t use much.

RATH: The fact that they give you a huge bunch doesn’t mean that you need to necessarily use it all. But you know, hey, if some people like it, I guess, go ahead. Live- live, live large.

GRABER: Side note to you sushi experts out there who are saying, “Hey, the green stuff on most American sushi plates isn’t real wasabi, it’s colored horseradish!” That’s true, and you can read more about it in Trevor and Eric’s books, or listen to us talk about it in our episode Espresso and Whiskey: the Place of Time in Food.

TWILLEY: But horseradish aside, good sushi will already be preseasoned, so in fact not only do you likely not need extra wasabi, you probably also don’t need to dip it in soy sauce. But if you do dip it, this is Trevor’s PSA.

CORSON: Yeah, if you want to add a little extra soy or if the chef instructs you to. If you pick up a nigiri piece of sushi, and you dip the rice side in the soy sauce, the rice immediately risks, you know, falling apart in the soy sauce dish. We’ve all had this happen, probably. So the trick is, there’s a way you can pick up a nigiri by putting your thumb and middle finger on the sides and your index finger on top and kind of using your index finger to sort of rotate the nigiri upside down. And then dip the fish side in the soy sauce. And then you can just quickly put that in your mouth.

GRABER: Notice that Trevor talks about how to hold sushi in your fingers. This was one of my revelations. I’m okay with chopsticks, but I find it really difficult to maneuver sushi with them. Turns out I’m not supposed to. And all of these rules of sushi are all about achieving the perfect rice and fish experience.

CORSON: Don’t dip the sushi in extra soy sauce, don’t use chopsticks, blah, blah, blah. There’s all these little etiquette things about it. It’s not that the rules are important, but it’s that the chef cannot use their ultimate rice-packing skill to produce the perfect nigiri for you if you’re going to do any of those things. Because it’ll fall apart. So. There’s a reason why you’re supposed to eat one nigiri at a time, with your fingers, from the chef without adding any extra seasonings or anything. Because that way the chef can pack it loosely enough.

TWILLEY: So all these rules that sound kind of fussy—like, does it really matter that I turn the fish upside down to dip it and hold it with my fingers instead of chopsticks? Trevor says yes, because it is transformative. This is what makes it possible for the rice to fall apart in your mouth and meld with the fish for maximum deliciousness.

CORSON: What sushi actually should be is such a different experience than what most people experience.

GRABER: The other thing that most people don’t experience is nori the way it’s meant to be eaten. Nori is typically quickly toasted before it’s rolled and it gets nice and crisp. And most people don’t eat their rolls quickly enough.

CORSON: But by the time you get it in your mouth, that seaweed paper has already gotten soggy. ‘Cause the rice is moist. And we don’t even realize this, but we’re sitting there eating soggy sushi rolls all the time. So the whole point of these sheets of nori is that they should be crispy.

TWILLEY: This is never going to be the case for a California roll or some other Americanized roll with rice on the outside. But if you get a traditional roll with seaweed on the outside, eat that roll first if you want to get the full crispy experience.

GRABER: But even with all these rules—the dish itself is always changing. It’s come a long long way from fish that fermented for a year, and it’s going to keep evolving.

RATH: One of the things that I learned writing this book is that there’s no period in time where sushi just gets set in stone, and this is sushi.

CORSON: I mean, the entire history of sushi is this endless process of evolution and it, it’s just still going on and on.

MATSUMOTO: And so I think more open-minded people would say, you know, the more the merrier. The more styles, the more creativity. The more the Japanese aesthetic can be, adapted to different cultures and countries.

RATH: I think sushi is the quintessential dish that’s created by, you know, many, many people. Today it’s a global food stuff. And we, and it gets reinvented all the time. And while there might be some sushi purists out there that say, oh no, California roll, that’s not sushi at all. No, no, no, no, no. It is! And maybe some guy in Czechoslovakia is putting beer in his, in his rice, and, doing a Prague roll or something. And that, that’s sushi too.

[MUSIC]

TWILLEY: Thanks this episode to Nancy Matsumoto, Trevor Corson, and Eric Rath, we have links to their books on our website gastropod.com.

GRABER: Thanks as always to our producer Claudia Geib, we’ll be back in a couple of weeks with a brand new episode, till then!