Konnyaku

*First broadcast on May 11, 2023.
Konnyaku is an important element of Japanese cuisine. It has long been known as a high-fiber, diet-friendly food, and in recent years it's been shown to offer benefits for health conditions including dementia and diabetes. Outside Japan, its popularity is on the rise, and it has started to appear in dishes like pasta. Konnyaku is a chewy, jelly-like food made from the extremely bitter corm of the konjac plant. How is it processed? And what other uses does it have? Peter Barakan visits Japan's top producing area to learn all about this surprising food.

Konnyaku features in various dishes, including fried noodles, colorful mochi rice cakes and even breaded cutlets
Peter Barakan tries making konnyaku by hand, and succeeds in achieving a wonderfully soft texture reminiscent of sashimi (raw fish)
Replica human organs made from konnyaku have been developed for use in surgical training

Transcript

00:23

Hello and welcome to Japanology Plus.
I'm Peter Barakan.

00:27

Our theme for today is konnyaku,

00:30

a food which has basically no flavor,

00:34

and a texture of firm,
slightly chewy jelly.

00:39

It comes in slabs like these generally,

00:43

or sometimes in these kind of noodle form,

00:46

which is called shirataki, which
translates literally as white waterfall.

00:51

It's been part of the Japanese diet since
just about forever

00:55

and is particularly popular
with people who are dieting

00:58

because it has very high fiber content.

01:01

Recently it started to be consumed
outside Japan as well

01:06

in pasta and in other ways too,
as we'll find out on today's program.

01:22

Konnyaku is a processed food made
from a plant called konjac.

01:26

It's been eaten in Japan for centuries.

01:32

It comes in many forms,

01:34

but one of the most common
is “ita-konnyaku”—a brownish-gray block.

01:42

For “shirataki,”
konnyaku is cut into long strings.

01:48

And for “tama-konnyaku,”
it's formed into small balls.

01:54

It has almost no taste,
and so it can be served in many ways.

01:59

It's a common ingredient in hot pots.

02:05

Sweet and spicy miso is a tasty way to
complement konnyaku's satisfying texture.

02:13

Konnyaku can also be prepared
in noodle form.

02:18

With very few calories and high fiber,
it is an excellent diet food.

02:26

It is made from the konjac plant,

02:29

which is known as “devil's tongue” due
to the look and smell of its flower.

02:33

In the West,
the plant is generally avoided.

02:39

But recently,

02:41

it was found that its main ingredient,
glucomannan, lowers blood sugar levels.

02:48

Another ingredient, ceramide,

02:50

has been associated
with a reduced risk of dementia.

02:56

Konnyaku is in fact
getting a lot of attention,

02:59

and today we'll learn all about it.

03:05

We've come to Showa,
a village in Gunma Prefecture.

03:10

Hello. Jindai-san, nice to meet you.

03:14

Hello, nice to meet you too.

03:18

Our guest is Jindai Hideaki,

03:21

an associate professor
at Utsunomiya University.

03:26

He studies “food systems,”

03:29

a topic covering agricultural produce
from production to consumption.

03:34

His work on konnyaku food systems
is especially highly regarded.

03:42

So here we are in rural Gunma.
The place is called Showa Mura.

03:46

I'd never heard of it until now. I hear it
has quite a lot to do with konnyaku.

03:52

Yes,

03:53

over 90 percent of Japan's konjac
plants are grown here in Gunma,

03:59

and Showa village
is the number one producer.

04:04

Today I'm going to show you
how konnyaku is made.

04:08

Okay. I'm interested to see,
because in the shops

04:11

you only see it in the processed
form that we actually eat.

04:14

So yeah,
my curiosity is already going mad.

04:20

It's often misunderstood.

04:22

Many Japanese think it comes from the sea!

04:26

I hope you enjoy learning the truth.

04:31

Our first destination is a shop
where village produce is sold.

04:38

Here they stock a lot of products
made using local konjac.

04:42

OK.

04:45

Over here you can see
what konjac looks like in the ground.

04:49

What?

04:52

Look at that.
What a strange-looking object.

04:57

Lumpy, isn't it?

04:58

Oh, what kind of plant is that?

05:02

Well, it's a kind of root vegetable.

05:05

Can you eat it in this form?

05:08

It contains oxalic acid,
which is poisonous.

05:12

If you tried eating that,

05:14

it would make your mouth hurt, so it can't
be eaten raw, boiled or grilled.

05:20

Here, we have a coagulant.

05:23

To make konjac edible,
you mash it and mix in the coagulant.

05:28

Then you can make the various forms
of konnyaku we're about to see.

05:33

OK.

05:36

Here we are. Quite a wide variety
of products, as you can see.

05:40

Yeah. You know, there's something
about konnyaku, it's mainly gray.

05:44

I mean, there's the white version, and
there's an almost black kind of version.

05:48

But there're other kind of shades of gray.

05:51

It's not a particularly
attractive looking food, is it?

05:55

Konnyaku made directly from the corm—
that lumpy object—is naturally gray.

06:03

Nowadays we use konjac flour,
which produces white konnyaku.

06:09

But we often use seaweed powder
to add color,

06:13

and to help the food absorb
other flavors more easily.

06:17

I see. Because it doesn't
have any particular taste itself,

06:20

it will assume the taste of whatever
sauces and things you put it in.

06:27

That says tofu konnyaku.
So does it actually have tofu in it?

06:32

Konnyaku doesn't have flavor,
so yes, soy powder has been incorporated.

06:38

It's a clever idea
from the konnyaku maker.

06:42

And this is from konnyaku too?

06:43

It's konnyaku rice porridge,
which contains very few calories.

06:48

Oh, it says...
I see 85 calories per portion.

06:52

Yes, that's all.

06:53

OK.

06:55

What do you think it is that made konnyaku
as popular as it is in Japan?

07:02

In the past, seafood was a crucial source
of food in Japan.

07:07

People who lived inland wanted something
with a similar texture to fish,

07:12

and konnyaku filled that role.

07:16

So, for example,
I'm sure you know about fugu, or blowfish.

07:20

Yes.

07:21

Konnyaku has a similar texture,

07:24

so it became known as “mountain fugu.”

07:27

And it was widely consumed.

07:31

I've heard that konnyaku is starting
to be consumed outside Japan as well.

07:36

But for example,
I mean, like if you take a block of this

07:40

and take it to, I don't know,
somewhere in Europe, for example,

07:44

I don't think people are going to know
what to do with that.

07:48

Outside Japan, konnyaku isn't often sold
in the forms we see here.

07:54

In the West,
it's gaining attention as a diet food.

08:00

So for example, in Italian dishes,
shirataki is marketed as “Zen pasta.”

08:07

It's an alternative to regular pasta.

08:10

Zen pasta, I love that.

08:12

In Hong Kong, it's served in tapioca tea,
and is known as “QQ.”

08:17

QQ?

08:18

Yes—it's said that “QQ”
as a sound conveys chewiness in Chinese.

08:24

It's quite easy to incorporate konnyaku
into other cuisines,

08:28

so it's flourishing
in very different ways.

08:32

It contains ceramide and glucomannan,

08:35

which may be effective against diabetes
and metabolic syndrome.

08:42

In other countries, many people
follow gluten-free or vegan diets.

08:47

Requirements like that.

08:51

So Japanese and international demand

08:54

are combining to produce the boom
we're seeing today.

09:00

The konjac plant is believed
to have come to Japan from China.

09:06

Its scientific name
is “amorphophallus konjac,”

09:10

and it's part of the araceae family.

09:15

Japan's earliest written record of konjac
dates back to the 10th century,

09:19

but the exact timing
of its arrival is unclear.

09:25

It was originally consumed as a medicine.

09:28

But it's perishable,
and—when unprocessed—extremely bitter.

09:34

Lye was used to counteract the bitterness.

09:37

Preparing this food
was very time-consuming.

09:43

It wasn't until the late 18th century that
konnyaku became widely eaten in Japan.

09:53

Documents from the time mention that it
has a cleansing effect on the intestine.

10:00

It has a unique texture and is easy
to combine with other ingredients.

10:05

Soon enough,

10:06

it was being sold on the street and being
mentioned in theatrical performances.

10:14

The renowned haiku poet
Matsuo Basho was a big fan,

10:18

and he referenced it in his work.

10:27

In this verse,

10:29

konnyaku is a favorite food that
is offered along with seasonal flowers

10:33

in memory of a dear friend.

10:38

By the mid-19th century,

10:40

konnyaku was so popular that it featured
in over a hundred different recipes.

10:48

A leading contributor to its popularity
was a farmer called Nakajima Toemon.

10:56

In 1776, he developed a method
of turning konjac into flour.

11:02

This made the production
of konnyaku a lot easier.

11:11

He sliced, dried, and ground konjac
into powder using a stone mortar.

11:17

This made it possible
for konnyaku consumption

11:20

to spread far and wide.

11:26

In powder form,
it was much easier to transport and store.

11:30

In Japan, China and elsewhere,

11:33

konjac flour
is now the standard item produced.

11:46

Hello everyone. I'm Kyle Card,

11:48

and for today's Plus One,

11:50

I am located in Ibaraki Prefecture
to visit a very special and niche shrine.

11:55

The konnyaku shrine.

11:57

Let's check it out together.

12:01

The town of Daigo is home to a shrine
that is known mostly to konnyaku insiders.

12:11

And here we are, the Junisho Shrine.

12:13

So within this area,
the konnyaku shrine is said to exist.

12:18

So...oh,
there's an English sign over here.

12:23

As you can see, konnyaku shrine.
This is the place.

12:29

Junisho Shrine was built in the year 727,

12:33

and was supported
by generations of feudal lords.

12:40

At the back of this prestigious venue
is the konnyaku shrine.

12:45

Is this it?

12:47

Up in the mountains here, it has to be it.

12:51

Ah, this is it. The konnyaku shrine!

12:56

The shrine was built in 1981,

12:59

using donations from people
in the konnyaku business.

13:03

For anyone associated with the food,
this is a special place.

13:10

That must mean
that a god of konnyaku is enshrined here.

13:15

But I don't know.
So I should probably ask.

13:19

I wonder if anyone's here.

13:24

Hello!

13:25

Oh, someone's here.

13:26

Yes? Can I help you?

13:28

- Are you the caretaker of this shrine?
-That's right.

13:31

This is the konnyaku shrine.

13:32

Does that mean
there's a konnyaku god enshrined here?

13:35

Well, the spirit enshrined here
is actually that of Nakajima Toemon.

13:42

In some places in Japan,
real people were enshrined as deities.

13:48

And this is one of those places.

13:54

Thanks to Nakajima Toemon,
konjac flour was widely distributed.

13:59

In the konnyaku industry, he's venerated.

14:06

Konnyaku sold extremely well.

14:09

People had a steady source of income.

14:11

And for that,
they gave thanks to Nakajima Toemon.

14:15

They would raise a glass in his honor.

14:18

Enjoy food and drink.

14:21

And they'd express their gratitude to him.

14:24

This shrine conveys
that sentiment in physical form.

14:28

So if you pray at this shrine,
what sort of benefits do you receive?

14:34

First, you'll be healthier.

14:37

And richer!

14:38

Really? OK.

14:40

You'll be able
to build a “konnyaku goten.”

14:43

Konnyaku goten. OK.

14:45

If you work hard and make
a lot of konnyaku,

14:49

you'll have enough money
for a konnyaku goten—a huge house.

14:54

So you're telling me
if I pray at this shrine,

14:57

not only will I become healthy
from eating konnyaku

15:00

I'll become so prosperous,
I can build a giant goten.

15:08

I'll just get to praying right away.

15:13

We're given special permission
to go inside.

15:19

Wow, it's so cozy in here.

15:24

It measures around 30 square meters.

15:28

Every April, people involved
in the konnyaku industry gather here

15:32

to offer thanks to Nakajima Toemon.

15:40

So here at the konnyaku shrine,

15:42

they don't offer money,
they offer konnyaku.

15:45

So I'm going to do the same.

15:49

Mr. Nakajima, thanks
to your determination and ingenuity,

15:53

konnyaku is now enjoyed all
over the world.

16:12

This is a konnyaku factory.

16:15

It makes products
for the international market.

16:20

Hello.

16:21

Hello.

16:22

Nice to meet you.

16:23

Nice to meet you.

16:26

This is the director, Hyodo Takeshi.

16:31

Whoa, what is that?

16:34

Konjac corms.

16:35

Well, we saw some of the smaller ones
in the shop, but these are enormous.

16:40

Is this an average size?

16:42

This is five years of growth.

16:45

After three, the corms are just right.

16:47

After five, the sprout gets really long,
and a single flower blooms.

16:51

Oh right.

16:53

All the nutritious elements go
to the blossom.

16:57

So three years of growth is best.

16:59

Ah, I see.

17:03

Konnyaku is often made
from processed flour.

17:06

But making it from scratch
generates a fresh taste.

17:10

That's interesting, because

17:12

you think of konnyaku as being
something that doesn't have any taste.

17:16

It has a freshness to it.

17:19

OK. I'm curious.

17:22

The factory makes over 20 products
using konjac flour.

17:29

Let's see how standard blocks
of konnyaku are made.

17:33

- Is it okay to have a look?
- Yes.

17:35

Thank you.

17:36

It's surprisingly interesting.

17:38

Oh, it's a big vat of water.

17:42

So what's this brown powder?

17:45

Seaweed powder. It adds the brown color.

17:49

Ah.

17:52

Looks like mud.

17:54

This is konjac flour.

17:56

Oh, wow. Okay.

18:02

The finished konnyaku shouldn't
be too soft, and it shouldn't be too hard.

18:07

It should be just right,
and this is the crucial stage.

18:12

Interesting.

18:18

So what are you doing here?
Stopping it and restarting it?

18:22

Well, if you leave it on,
it makes a whirlpool that sucks in air.

18:28

That ruins the konnyaku,
so I avoid doing that.

18:34

Oh, it's getting creamy now,
isn't it? Yeah.

18:38

The pipe adds hot water.

18:41

The konjac flour dissolves,

18:43

and over time,
the liquid acquires a thick consistency.

18:52

It's left to sit,
and the surface scum disappears naturally.

18:58

This raw material is poured into molds,
and left to set overnight.

19:11

The konnyaku in the large molds is cut
into smaller blocks.

19:15

Then it's placed in here.

19:18

And, here's a finished block.

19:23

Next, Peter is going
to try making konnyaku himself.

19:29

Cooking class!

19:32

We mix konjac flour into water.

19:35

It's the same process we saw earlier,
but this time we'll use chopsticks.

19:41

Alright. I can do that, I'm sure.

19:44

Keep going till it thickens.

19:46

Okay.

19:47

You're doing good.

19:52

OK, OK.

20:00

Good.

20:01

OK, that's done. Alright.

20:04

40 minutes later, it's solid.

20:06

Oh, yeah, right. It's kind of like jelly.

20:08

It's become firmer.

20:10

But it's still too soft,
so we mix it with a coagulant.

20:17

Let's do 500 grams.

20:21

The mixture is transferred to a tray.

20:28

Then it's steamed
at 70 to 80 degrees Celsius

20:32

for around 30 minutes.

20:35

Let's open it up.

20:36

OK.

20:41

It's become konnyaku.

20:43

OK.

20:49

It solidified nicely.

20:50

Right.

20:52

Presumably you don't eat this hot though?

20:55

We'll cool it down.

20:57

Oh, right.

21:00

...Using ice.

21:02

Konnyaku solidifies when heated,
and softens when cooled down.

21:08

Oh you're right, yeah, it's really soft.

21:10

And transparent.

21:10

Yeah.

21:11

It's like raw fish—sashimi.

21:14

Oh yeah, look. It's transparent.

21:22

Well, that's great. It really does feel
like sashimi, doesn't it?

21:25

That's fantastic.

21:29

Delicious.

21:33

The factory makes a wide range of products
that are exported to other countries.

21:42

The products are developed
by visiting different locations in person,

21:47

and seeing how people react to them.

21:52

I have a sneaking feeling
that you're going to tell me that

21:54

all of these contain konnyaku.

21:57

Yes, they do indeed.

22:00

What is that?

22:01

A breaded cutlet.

22:04

It's like fried fish.

22:10

That's really good.

22:12

It has the consistency of a kind
of slightly chewy fish cake.

22:17

The texture's really good.
How do you do that?

22:20

We add soy pulp,
and mix it in a certain way.

22:25

OK.

22:26

Then we freeze it,
and remove water to create the texture.

22:30

Okay. Very clever. This is really good.

22:33

So what are these here?

22:34

Well, they're like “mochi” rice cakes.

22:38

Let me try the sesame one,
because I'm a sesame freak.

22:46

They taste like real mochi.

22:48

Mmm. Quite soft. Mmm, it's really good.

22:51

Wow. I'm impressed.

22:54

This stuff is all really great.

22:57

So are you actually marketing these now?

23:00

Yes. Right now we're selling noodles
in the international market.

23:05

Which countries are interested
in this kind of thing?

23:09

Well, for example,

23:10

there's a Hong Kong chain of coffee shops
with branches around the world.

23:16

It sells konnyaku noodle salad.

23:19

Okay. Interesting. Interesting.

23:24

Konnyaku is also attracting attention
outside the world of food.

23:32

This company, based in Saitama Prefecture,
manufactures medical products.

23:40

They create replica human organs

23:43

that students and trainees
can use during surgical training.

23:50

And—yes—they're made of konnyaku.

23:58

This is a replica of a human lung.

24:02

The texture, elasticity and position
of the blood vessels

24:06

are just like the real thing.

24:09

The replicas are perfect
for practicing techniques like suturing,

24:12

and they're being widely adopted.

24:19

The company president, Takayama Seiichiro,

24:22

was searching for an alternative
to the resin and pig organs

24:26

that are used for conventional replicas.

24:31

He hit upon the idea of using konnyaku.

24:35

A few years ago,

24:37

raw liver was banned in Japan after
a series of food poisoning incidents.

24:44

I saw a news story about red konnyaku
being served as an alternative.

24:50

And that's when it hit me:

24:51

maybe it could be used to
make replica organs for surgical training.

24:57

At first, things didn't go smoothly.

25:04

It was a bit coarse

25:06

and we weren't entirely sure
that we could simulate organs.

25:10

But we carried on refining it,

25:12

and gradually the feedback
from doctors improved.

25:18

The resulting artificial organs
don't fall apart when pulled open.

25:23

They're also half the price
of other replicas,

25:26

which can cost hundreds
of thousands of yen.

25:29

And so now they're making quite an impact.

25:37

I look forward to the day
when doctors all around the world say that

25:41

during their training
when they were younger,

25:43

they used the organs that we made.

25:47

I want these replicas
to become the standard,

25:51

everywhere from the Americas
to Africa to Europe.

25:57

That would hopefully lead
to better outcomes for patients.

26:02

And if that happens,

26:04

then our replicas will have
made a real difference to global health.

26:09

That's our goal.

26:11

Who would have thought
that medical students

26:13

would be using konnyaku for dissection?

26:16

That was amazing.

26:18

So far, konnyaku has mainly
been developed as a food,

26:23

but as we've just learned,

26:25

it can be useful in other fields,
in various brand-new ways.

26:30

It has so much potential.

26:34

I suppose it's because konnyaku is more
about texture than anything else, really.

26:38

So if you use that texture
for any number of other things,

26:42

I mean, all it takes is,
I suppose, some imagination.

26:45

So there's probably no limit to
what it can be used for.

26:50

I agree.

26:51

Another example is space food.

26:55

Research is being carried out on how
konnyaku might be used for that purpose.

27:00

One day, konnyaku might be used not only
in Japan and other countries,

27:05

but in space!

27:08

Space food? Wow.

27:11

What do you think of everything
we've seen today?

27:15

I was just amazed
at the variety of different foods

27:19

that can be made from konnyaku.

27:21

Because I'd only had it
in the more traditional ways up to now,

27:24

but I mean that that cutlet, for example,

27:28

I can imagine that being
a real hit product in the future.

27:31

And also those slightly softer,
kind of mochi kinda sweets.

27:37

Those things were all delicious.

27:39

I'm really, really interested to see
how that market develops,

27:43

and I'm sure it'll be very successful.

27:45

So it's been an interesting day.
Thank you very much.

27:49

Thank you very much.