Tokyo: this world-class metropolis is a veritable gourmet wonderland.

Discover the stories behind the ingredients that make this city so delicious - so "oishii."

Japan is a fermentation powerhouse, with methods and recipes dating back centuries.

"Miso," soy sauce, "natto," pickles, you name it...

all kinds of regional foods reveal a rich culture that's lasted generations.

Wow, it's got a really deep color, and just by the look of it, it looks like it's kind of compact and solid.

It has a sweet aftertaste.

- Yeah?
- Quite refreshing.

Japanese fermented foods are gaining traction overseas.

In fact, miso and soy sauce exports have doubled in the past decade.

You can even try making miso at this workshop in Paris!

It's cool that we're able to
try making it ourselves!

Sake breweries are popping up across the globe, and their numbers are growing.

Fermentation is at the core of Japan's food culture.

It's not just about preservation;

fermentation gives ingredients new life, enhancing nutritional value and, yes, umami!

This time, we'll take a closer look at how Japan's fermented foods are taking the world by storm.

Trails to Oishii Tokyo.

Hi, I'm Michael Keida.

I'm from America but I've been living in Japan for about 20 years now.

This time our theme is fermented foods.

Now, fermented foods have gained a lot of popularity in recent times,

thanks to their health benefits as well as their robust flavors that they provide.

Now, in Japan, they have a long tradition of using fermented foods.

For example, soy sauce or sake...

But today, the first thing we're going to check out is miso.

Let's get started.

Michael begins at a miso specialty shop in Kameido, a historic area of Tokyo.

Wow, check out all these different varieties.

It's just got this really robust smell of miso in here.

Around 70 kinds of miso fill the shop.

Miso expert Sano Noriko will tell us more.

What ingredients make up miso?

Soybeans, salt and "koji."
Those three.

Many varieties from three ingredients?

Right.

Japan is long, stretching north to south,
so regional climates vary greatly.

Also, there are three main types of koji:
rice, barley and soybean.

There are others, but those main types
make rice miso, barley miso and soybean miso.

Koji, a product of koji mold cultivation, is a key ingredient in fermentation.

This is rice miso, specially made
using mochi rice. It's the most popular.

Try some.

It's got a really full flavor to it.

Actually, I can imagine using this for soup, but you could also, you know,

just take an ice-cold cucumber and dip it in there and crunch on it.

It'd be excellent.

This is a white variety.

What makes it a different color?

The main reason is the maturation time.

It's shorter for white miso.

Have a taste.

- It's very different.
- It is.

It's got a little bit more punch - almost a sour flavor mixed in with a saltiness.

It's great for making miso soup packed with veggies.

- Or just with green onion and "wakame" seaweed.
- Absolutely.

Barley koji produces barley miso.

I can feel the barley grains.

Wow, it's got much more of like...

I really taste the fermentation and that...

it's got a little bit of a chewiness to it.

You can crunch down the barley, and really get a punch of that fermentation in.

And soybean koji makes soybean miso.

Almost looks like a playdough.

It's really quite compact in flavor, and it takes a while to dissolve it in your mouth.

Once you do, it's got a little bit of sharpness - almost like, reminds me of a sharp cheddar cheese,

and there is a little bit of sourness to it.

Very interesting.

It's amazing that you get such different
flavors from three base ingredients.

Do you get many overseas customers?

Yes, we get miso lovers from
all around the world every day.

Society is growing more health conscious.

Fermented foods are nutritious and easy to digest.

That's one reason why miso
is getting more popular worldwide.

Among the different types, soybean miso is said to have the longest history.

Michael heads to Okazaki in Aichi, 300 kilometers west of Tokyo, to find out more.

"Hatcho miso" has been made in this castle town for 400 years.

It's the mother of all soybean miso.

Michael visits a long-established producer.

Hello.

Asai Nobutaro will offer a tour of the warehouse.

- In here.
- Wow!

- This is our miso warehouse.
- Amazing.

Inside are over 200 wooden barrels, each about two meters tall.

For hatcho miso, cedar wood barrels are used for fermentation.

Another key point is the stones piled on top.

One barrel produces three metric tons of miso.

On top of that, three metric tons worth of stones.

Hatcho miso is made using little water,
like it was during the Edo period.

Is that why you put weight on top,
to push out water?

No, there is little water from the start.

We need to put stones on top
to distribute moisture evenly.

Less moisture means slower fermentation,
so it takes over two years to make.

During the slow process, soy proteins
are broken down into tasty amino acids.

Soybean koji is made by growing koji mold over steamed and ground soybeans.

This and salt water are all you need to make hatcho miso.

With koji mold, starches are converted to glucose, and proteins are broken down into umami-packed amino acids.

Once everything is placed in the barrel, trapped air needs to be forced out.

This prevents the growth of bacteria that feed off oxygen,

allowing lactic acid bacteria and yeast to lead the fermentation process.

Stones are then piled on top to help moisture spread evenly.

Some stones weigh up to 60 kilograms.

They are piled up with great precision.

So well, in fact, it's said they don't topple over during earthquakes.

Lactic acid and yeast bacteria inhabit the warehouse, entering the miso to form complex flavors.

And slow fermentation gives hatcho miso the depth it's famous for.

These look very old.

The oldest ones have been used for over 160 years.

Generations of microorganisms
live in the wood fibers.

That allows us to produce a
similar flavor for many years.

Wow.

We put a cloth sheet over the miso.

And stones are placed on top of that.

I thought the stones were on a board,
but they're right on there.

Right, miso moves during fermentation.

That causes the stones to shift as well.

You can hear them shifting when
fermentation is active in midsummer.

That movement controls, or conducts,
the fermentation process inside.

That helps the miso do its thing.

And the result is even fermentation.

Microorganisms and skilled producers coexist, working patiently to make the best hatcho miso they can.

After two years, the hard work has paid off.

It's got a really deep color, and just by the look of it, it looks like it's kind of compact and solid.

We scoop it out like this.

Michael gets the first bite.

It smells like cacao.

"Itadakimasu."

It has a... it's kind of... the flavor, it's similar to me, is tomato paste.

I can imagine using this in Italian cooking.

It's got a little bit of a tart flavor, and again, that umami that you get with dried tomatoes.

Even eating it straight, it's not so salty.

Saltiness dissipates over two summers and winters.
That's complete fermentation.

It becomes more natural as the bacteria grows.

Asai has been exporting hatcho miso products overseas for over 50 years now.

This was developed specifically for the international market.

Miso is dried in warm air over a long period of time, forming a powder.

He recommends eating it with vanilla ice cream.

Are you sure this isn't cocoa?
It really looks like it.

I love ice cream, but I've never tried it with miso before.

I've tried all kinds of flavor combinations but this is a first.

"Oishii!"

It's like having cacao crumbs on top,
but it tastes even richer.

A bit sour and bitter, with umami.
It's a full spectrum of flavors.

Miso tends to have complex flavor.

Taking good care of the microorganisms
living in the barrels makes great miso.

We have to take the process very seriously.

My emotions are transmitted
to the organisms in the miso.

It sounds dramatic, but I think
that's what making miso is all about.

Living in harmony and working hand-in-hand with nature, traditional flavor is preserved.

Miso is getting pretty big in Paris.

Michael speaks to 25-year Paris resident Tominaga Maki to find out more.

Hey, Maki! Bon jour.

Bon jour!

Can you buy miso easily in Paris?

- Yes, with many to choose from.
- Really?

Miso soup is well-known, so you'll
find lots of instant soup products.

But miso itself is being used in cooking more,
so there are many varieties on the market.

- Yuzu miso, for example.
- They have that?

Yes.

- That looks convenient.
- Yeah.

Here's something you may not see in Japan.

Interesting.

It's cubed miso.

It's packaged like butter.

Right, miso for one serving.

What can you tell us about
fermented food in France?

- Well, as you know, cheese is a fermented food.
- Right.

Pickling vegetables in jars
has always been common practice.

But I think Japan puts
more emphasis on flavor.

Cheese is an exception though.

Japanese fermented foods are
both healthy and delicious.

Chefs often say, while French fermented foods
are healthy, they aren't so elevated in flavor.

So, more chefs are studying
Japanese fermentation these days.

Hugo, a man who trained at a famous
French restaurant, is offering workshops here.

I participated and took a video
that I'd like to show you today.

A miso workshop here, on a quaint street in Paris.

Once a chef at a starred Paris restaurant, organizer Hugo Chaise now makes and sells his own miso.

He's been hosting monthly workshops for the general public since 2021.

This is the koji he uses.

He made it himself, growing mold over rice.

He begins by explaining the importance of koji in the fermentation process.

Now, each participant gets to make their own 1-kilogram batch of white miso.

The ingredients?

Steamed soybeans, salt and koji.

Ingredients were put through a meat grinder.

I thought that was very French.

It must be kneaded well.
Let it be a stress reliever!

He says to push out all
my stress from the week.

Hugo's interest in fermentation began when he did part of his training in Japan.

Discovering miso and soy sauce
changed everything for me.

They're delicious, but not so
commonplace in Europe.

I discovered them in Japan,
realized their power, and experimented.

Miso is like a magical paste.

It makes a dish tastier,
with little skill required.

It's key to get rid of large air pockets.

When the temperature rises and fermentation begins,
air that's trapped inside will burst, he said.

He also holds workshops for professional chefs, where he teaches how to make koji.

I'd eaten miso at restaurants,
so it was cool to see how it's made.

I have many favorite
Japanese restaurants in Paris.

Miso is a key Japanese ingredient.

It's cool that we're able to
try making it ourselves!

Hugo makes miso from corn, rye, and other products.

He will use them to make unique French dishes today.

Here, he prepares something called butter miso.

Rye miso is mixed with an equal amount of unsalted butter for a simple, tasty recipe.

Very soft.

"Itadakimasu."

The miso flavor is robust,
but it's more sweet than salty.

Similar to peanut butter.

Next up, pasta.

He adds gnocchi to pumpkin miso and butter mixed in a pan.

That looks great.

He mixes it well.

Seems easy to prepare.

It's just butter and miso?

That's it, yeah.

Lots of different aromas.
The miso, and some pumpkin.

I bet that was good.

Hugo's a famous chef, so the dishes were perfection.

- Seems like a fun workshop.
- Definitely.

Look at this.

I check this bottle every day.
There's movement here.

It was packed tightly at first.

But that changes over time.
It's interesting.

French cuisine has always been
popular around the world.

I'm excited to see where the influence
of Japanese fermentation takes it.

Thanks for sharing the video with us.

My pleasure. Thank you.

Japan is home to a wide variety of regional fermented foods.

Ogura Hiraku, a self-proclaimed "fermentation designer," will tell Michael more.

After researching fermentation in university, he shared his knowledge through books and social media.

Japan has a lot of regional foods,
so how many fermented products are there?

At least several hundred types,
depending on how specific you are.

What's this?

Fermented bean curd from Okinawa.
It's fermented tofu cultivated with mold.

- I love tofu, so I gotta try this.
- Please.

Just nibble it.

It's just got a really smooth, almost like a thick pudding type of texture to it.

And it's got sweetness but a little bit of tart as well.

It just keeps on throwing up like a firework show - just throwing up flavors in my mouth.

So good.

- Excellent. That hits the spot.
- Great.

This is fermented crucian carp prepared as "nare-sushi."

This is crucian carp lacto-fermented with rice.
It's similar to a fish-flavored cheese snack.

"Itadakimasu."

"Oishii."

It's quite sour.

Almost as if lemon was squeezed on top,
but no lemon, right?

Right. Lactic acid bacteria make it sour.

Interesting.

So why is it that Japan has such a wide variety of fermented foods?

Ogura explains.

Japan is a long country with four seasons,
so there's a wide variety of microorganisms.

Namely, fermentative bacteria
that's resistant to salt.

Those bacteria help prevent spoilage
when food is stored in salt.

They also help with edibility and flavor.

Using several microorganisms enhances
the flavor of just one food item.

It's amazing how complex the flavor can get.

"Bettarazuke" is a good example.
It undergoes two processes.

- First, it's salted and lacto-fermented.
- Lacto-fermented?

Like sauerkraut.

Then, you do something you
wouldn't do with sauerkraut.

That's fermentation with koji.

It brings out sweetness and umami.

- The result is a complex mix of sour, savory, and sweet.
- Wonderful.

"Itadakimasu."

"Oishii."

You're right. It's complex.

There's a sour flavor,
then the sweetness comes.

In Japan, things like miso, soy sauce and sake are made using "nihon koji kabi," an indigenous strand of koji mold.

This is nihon koji kabi.
It's koji mold.

When you sprinkle it over rice and warm it,
the koji mold grows and gets fuzzy.

That creates the koji base used
to make various things.

This is something often made at home.
It's a mixture of salt, koji and water.

- Oh, shio koji?
- Exactly.

Shio koji is a mixture of salt, water, and rice koji that's often used as a marinade.

Give it a try.

It's salty with good umami.

Yes. Koji mold brings out two flavors.
One is umami, like in the "shio koji.

The other is sweetness, which you can
taste in "amazake," or sweet sake.

Ah, gotcha.

This traditional non-alcoholic beverage is a mix of rice koji and porridge that's fermented overnight.

- "Oishii."
- Right?

- It is pretty sweet.
- Yeah.

Amazake and shio koji look very similar,
but the flavors are totally different, right?

The reason is fermentation temperature.

Fermented at different temperatures?

Controlling temperature and humidity during
koji fermentation offers different flavors.

Umami, sweet, or even sour.

Japan's fermentation culture is centered
around this difference in how koji is used.

Flavor is determined by controlling
the environment koji ferments in.

It's what gives Japanese cuisine
such a wide range of flavors.

The use of "kombu" kelp and "katsuobushi" stock
makes Japanese cuisine unique from others.

The other key difference is koji.

Actually, kombu kelp and katsuobushi
are part of Japan's fermentation culture too.

So, fermented food is the core of Japanese cuisine.

But more precision goes into the use of koji.

No koji, no Japanese food?

I think it'd be boring without koji.

Koji is the foundation of Japan's fermented foods.

A profession called "tanekoji-ya," or seed koji production, is said to date back 600 years.

It's dedicated to the preservation and cultivation of nihon koji kabi, which is sold to producers across the country.

Only about 10 tanekoji-ya remain in Japan today.

Michael visits a long-established lab in Toyohashi, Aichi.

Michael gets a tour of the action.

Wow, it's high-tech lab.

Look at all these beakers.

I haven't really seen some of the stuff since high school.

Here are some koji mold samples.

They have different colors.

There are different types and colors.

Koji for sake, miso, soy sauce or other things.

These two are used to make "shochu" liquor.

So, you can't make shochu without them?

- Right, they're key ingredients.
- I see.

So, flavor is determined by koji,
not other ingredients?

Well, koji also impacts flavor,
recent studies have shown.

Part of their job is searching for new strains of mold.

Their other job is even more crucial.

Nice!

About 3,000 koji mold strains are stored in a controlled environment.

The strains die easily.

They're hard enough to find,
let alone preserve.

It's an important job, to say the least.

0.03 grams of koji mold are added to 30 grams of rice, and stored in a sterilized room.

In the controlled environment, bacteria grow on rice during a one-week cultivation process.

Then, more rice is added, and cultivation continues for another week.

- It's completely covered in mold.
- Right.

This is after a week of cultivation and drying.

Looking really close to this, it's almost as if I'm looking into a jungle.

It almost looks like small mushrooms just poking up everywhere.

You can see there's a whole community going on down here.

- May I touch it? With my bare hand?
- No problem.

Feels so strange.

It feels like I'm touching bits of Styrofoam, but it's got a really silky, light, powder on top of it.

This koji mold is used to make soy sauce.

Powdery spores are removed from the surface of the rice, leaving behind the koji base used for production.

It's then sold to producers across the country.

Koji mold cultivation in temperature-controlled warehouses, called "muro," has likely taken place since long ago.

The practice has been the foundation of the koji business for 600 years,

symbolizing Japan's rich history of fermentation.

Michael speaks with Murai YuIchiro, a descendent of the warehouse founders.

The idea is maintaining quality source koji,
and repeatedly cultivating mold from that.

Preserving the quality of koji starters
keeps production quality stable.

Wine is fermented using yeast found on
the surface of grapes grown outside.

They use microorganisms
from that area's land and air.

In Japan, for koji mold production,
we bring microorganisms to warehouses.

In other words, the process is more
industrial than agricultural.

That's what sets our fermentation
culture apart from other countries.

Koji cultivation began in this way about 600 years ago,

marking a major turning point in Japan's unique fermentation culture.

New York City in the US is no stranger to excellent food.

Each year, a Japanese fermented foods event is held here.

About 600 types of sake brewed in both Japan and the US go on display, attracting sake lovers from across the country.

Sake - fermented booze made of rice, water, and koji - is loved all over the world.

Japanese exports have more than doubled in the last 10 years,

but there are now over 35 sake breweries located across the globe, with more popping up all the time.

One in particular is about to become the largest in the US.

Michael gets online for a chat.

There you are. How's it going?

Hey. There he is. Good morning.

How are you doing, Michael?

Good. How are you, Justin?

Pretty well.

Can you tell me about what you're doing?

Yeah, sure.

So we have just opened or just about to open the very first sake brewery in the state of Arkansas.

Wow.

There are a handful of sake breweries in the United States -

we'll call it about 20 or so, give or take, commercial breweries of different size and scale.

But we will be the largest, entirely US-owned sake brewery here, when we do officially open, any day now.

Arkansas here produces about half of the rice of all, half of all the rice grown in the United States.

Making sake is one thing, but kind of the main goal was:

how do we find a way to really give back to the agricultural, the growing community here

that's been, you know, the lifeblood of the United States for a long time.

And, you know, to be able to take something like sake,

and to highlight something like rice that is arguably undervalued and underappreciated,

you know, we thought this is the place to do it.

I think it's really admirable too that you're looking at...

I'm also from the States.

There's not as much of a culture to eat rice as there is in Asian countries.

But you're adding kind of a... you're showing more value in rice products by showing a different way to use it

which is, you know, making excellent sake, right?

So, to be able to take something so simple and have so many really delicious diverse expressions that you can do from that,

I can't think of a better thing to really highlight the quality and the value of that agricultural product.

So, you know, by making sake, we can play a small hand in helping people not only know about that,

but also care and appreciate it, then, you know, it's a win-win for everyone.

Yeah, that sounds great.

Nearly half of US-grown rice comes from the plains of Arkansas.

For its sake, Justin's brewery contracts farmers to grow a brand of rice for "yamada-nishiki."

The brewery has nine employees.

Their initial production target is 500,000 metric tons of sake per year.

They hope the product makes its way to smaller towns as well, so everyone can have a taste.

Oh, what's that? Is he putting the seeds?

Yes, so then what you're looking at here, you can see now the rice is sort of spread out across the length of the table.

And what they're doing is, they're applying the koji, the spores,

and trying to apply that evenly, to the degree possible,

across all of the steamed rice that spread out across the table.

In a controlled environment, rice is mixed in stages over the course of three days to create koji.

We already know that water is a key ingredient for sake.

As the name of the brewery's hometown suggests, Hot Springs has some pretty good water.

Steamed rice and koji are mixed with local water, yeast is added, and fermentation occurs over about two weeks.

After about two months of repeated heating and filtration, the sake was ready for its first shipment in August 2023.

This is sort of what it looks like.

Wow.

In the glass. Something like so.

- Has a nice color.
- Clear and beautiful.

Yeah. Just like a bit of a, a bit of a light sort of golden straw.

Real smooth.

It's got a real nice sort of baseline of umami.

- So I think that's kind of what makes sake special.
- Yeah. Yeah.

Just being able to have that, it's part of what makes it unique.

You got that, you got some of the... you got a bit of that koji-ness.

I liked how you said that you can still taste the koji in there because,

you know, those who don't drink Sake very often might not know,

but sometimes you get a sake and it tastes almost close to wine or it tastes completely...

it doesn't have as much of that.

But then others you try, you're like, oh, wow, that's sake.

So, you know, there can be such a wide range in there,

and it's nice that you're allowing folks to see or to taste the koji behind it.

I think that's really an important point.

Justin lived in Japan for about 15 years until 2022.

During his time there, he worked in the food industry and trained at a sake brewery.

Can I ask you... you obviously love sake now, but what was it that got you into it in the first place?

For the last, gosh, 12, 13 years or so, I've been working a lot, as I mentioned, with makers and growers of food or beverage.

And so, part of it was having the opportunity to discover

not just sake but fermented foods that are made with koji in particular, so miso and soy sauce, some things -

those things that are really, really, well-made and just really wholesome and delicious.

I feel like when you have something that's truly delicious and truly nourishing, your body recognizes that as well.

And it was an experience that I had not ever had with other types of food

and I had a lot of digestive issues and things,

and I just sort of had given up and assumed that it was something I had to live with then.

You know, I'm by no means cured, but I found that, one, moving to Japan first,

but then also finding these fermented foods and beverages,

and integrating those just proactively into my diet without doing anything crazy,

just eating and drinking good, real food, fermented foods, I felt a whole heck of a lot better.

From my experience, it was the best version of life in Japan for me.

Well, thanks a lot for your time. Appreciate it.

Thanks a lot. Michael.

Thanks for, yeah, thanks for getting up early and chatting with us.

Natto is a fermented food that's common in Japanese households.

It's texture and smell had kept it from taking off overseas.

But recently, natto is gaining traction as a superfood in the US.

Your grocery store may even have some!

A natto company in the state of Vermont says the food is getting so popular,

they're having a hard time keeping up!

They ferment steamed soybeans using a bacteria called hay bacillus, found in rice straw.

It's sprinkled on the beans and left to sit for a day.

The healthy, live bacteria multiply inside the intestines, promoting health benefits.

They've even pioneered a new recipe.

Make homemade doughnut slices, spread some natto to make a sandwich, and top that with sugary soy sauce.

The workers' families love it.

The company started about seven years ago.

Natto sales have gone up 50% in the last three years, with shipments now reaching as far as Alaska and Hawaii.

So, is American natto tasty?

It's still got the same type of "nebari," sliminess to it.

Let's give it a shot, American natto.

Oh wow.

"Oishii."

It is a little bit different.

It doesn't have the same seasoning as a typical Japanese natto.

It's got a little bit softer texture.

It's quite delicious.

If it weren't for fermented food, there would probably be no Japanese cooking,

because it is incorporated into every dish, whether you're talking about soy sauce or miso or natto or koji -

it's really hand-in-hand with Japanese cuisine.

And it's changed my life since I've come to Japan.

I've incorporated it more within my daily routine, and I can feel the health benefits from it.

And I'm hoping that, through learning about fermentation, the Japanese cuisine,

that everyone across the world might start incorporating these into their diet more often,

not only to find the health benefits, but also just the richness and the depth of flavor they can bring to your pallet.

Alright, nothing finishes a meal better than a nice glass of sake.

Cheers!

In Tokyo, every ingredient has its own story.