If you look up the food “konnyaku” in a common Japanese to English dictionary or translator, chances are you’ll get something along the lines of “jelly made from the starch of devil’s tongue”. Well what the heck is that? I’d never encountered this strange food until I went to Japan, and it was a new and confusing thing to me and all of my friends.

What is this “devil’s tongue” and what exactly is konnyaku? Why is it so gelatinous and why does it come packaged in big blocks? Perhaps you’ve been confused or mesmerized by this strange food before. If not, this post will open your eyes to the great mystery that is konnyaku.

First Off, What is a Devil’s Tongue?

konnyaku-plantsEventually I found out that a Devil’s Tongue is an Asian perennial plant, and it looks like the picture above. Konnyaku is made from the root of this exotic plant, and that explains the most common dictionary definition for it. It comes packaged in blocks of konnyaku, and can be pressed into a grid of blades to create konnyaku noodles which are called shirataki.


In America, I don’t think I’ve ever seen a block of konnyaku, but I am pretty sure I have had dishes at restaurants with shirataki and just didn’t know what they were at the time. Also, the Devil’s Tongue plants look pretty cool in my opinion. But if it wasn’t for konnyaku, I’d probably still have no idea what they even were.

What it Tastes Like and How it’s Made

konnyaku-rootsThese are konnyaku roots

Konnyaku is firmer in consistency than most gelatin and also has very little taste on its own. It tastes a little bit like salt, but that’s it. Similar to tofu, konnyaku is used more for its texture than its taste. It also tends to soak up the flavor around it, or whatever it is cooked with. Konnyaku blocks also come packaged in pre-soaked flavors, like spicy konnyaku.

Eating raw konnyaku by itself is not all that pleasant. We tried tasting a block of konnyaku just by itself to see what it was like while we were in Japan. It was weird. Our Japanese friends giggled at us for doing this. However, when konnyaku is prepared properly, it is actually quite pleasant. Shirataki noodles are really cool and give dishes an interesting and unique bit of texture.


Konnyaku is made by mixing flour made from the Devil’s Tongue root with water. Hijiki (a brown sea vegetable that grows on rocky coastlines) is often added for color (without any additives, konnyaku is a pale white) and flavor. The mixture is boiled and then cooled to solidify. Thus, konnyaku as we know it is made.

Konnyaku as a Diet Food

dietKonnyaku is also very popular as a diet food for a variety of reasons. Konnyaku is about 97% water and the remaining 3% is made up of fiber, protein, starch, and minerals. A normal block of konnyaku has a maximum of about 10 calories, but it’s very filling.

The fiber contained in konnyaku is extremely difficult for humans to digest so it usually just goes through your body and “sweeps out” your digestive system. Because of this, konnyaku is sometimes known as a “broom for the stomach” in Japan.

Konnyaku is gluten-free too. There have been lots of various studies concerning konnyaku and its ability to normalize cholesterol levels, prevent diabetes, and lower high blood pressure. Konnyaku is a pretty healthy food.


I like konnyaku, and I kind of wish I got to experience it more often. Like tofu, konnyaku can either subtly add a lot to a dish, or (when used improperly) can be a strange distraction from the meal. The bouncy texture of konnyaku livens up dishes and can really make some things more fun and enjoyable to consume. It’s kind of goofy just on its own though.

So tell me, have you ever tried konnyaku before? Either in block form or noodle form? How do you like it? How do you think it compares to foods like tofu? Share your thoughts in the comments!

  • pipokun

    konnyaku has always been kind of blah to me since i was kid. but i can definitely appreciate it now as an adult, especially with the health benefits. i like it the best in oden!

  • zoomingjapan

    I do eatkonyaku as part of my bento several times a week. However, I’m not too fond of it. To me it doesn’t taste like much. I prefer food with stronger tastes, such as natto. :D

  • Michael Beasley

    Fun fact about the Devil’s Tongue (also known as a Voodoo Lily): The flower smells like rotting meat, and is pollinated by flies.

  • Tara

    I work at Mitsuwa in Los Angeles and we sell this stuff a lot.

  • pipokun

    i would hope so..mitsuwa is a japanese market….

  • Alvin Brinson

    I’ve read about this before. Seems like a great diet food as you point out, and I wonder why it isn’t available in the US? There doesn’t seem to be anything that’s a very good substitute for it.

  • pipokun

    easy to find at any decent asian market that carry japanese goods.

  • April Roberts

    I just have to say, that last picture is just…uh…no, just no. I would try it (I am a vegetarian), but it would have to look different.

  • Rachel

    Once I tried mixing shirataki noodles with natto. I like both separately with other things, but together they make the most repulsive combo.

  • Jusilla

    Hmm I will have to keep an eye out for this next time I’m at the Asian market! Thank you for sharing!

  • Ricardo Caicedo

    I had no idea that konnyaku was made from such plant. I thought it was from potatoes or something : )


    I love shirataki. They are great in Western preparations too. Konyaku block is good for sukiyaki too.

  • Tiffany Harvey

    You can find it in the US at Asian markets. We bought some recently to make Oden. It was not bad, but I did cut the strips a little too large so you ended up with a big mouthful. Smaller is better!

  • anni

    i think that’s just a sample picture. i have never been served konyaku that looks quite like that. that’s because it always comes with something — broth, vegetables, meat, or maybe all of the above. it looks a lot more appetizing cooked. ^-^;

  • snorenose

    Konnyaku + red miso = tasty health food

  • koichi

    mmm delicious, makes me want to eat…

  • Kanrei

    I had once shirataki, but I didn`t like the taste of it… O_O (I prepared it with soy sauce and so…)
    Maybe I should give Konnyaku a second chance.
    I found it to buy in Japanese stores.

  • Jojo

    Great article. I’ve heard from my Japanese teacher that in many schools in Japan, Konnyaku is banned because too many girls bring them in lunches and eat them as a diet food. I don’t know if this is entirely true or not but I thought it was hilarious!

  • Laika

    Sounds like it would make a great dessert with some fruit and stuff :)
    Isn’t it weired to have a jello-thingy floating in you meal? Never tried it yet, definately will, but the texture doesn’t make me want to put it in something else :/

  • April Roberts

    Now THAT sounds appetizing! ;)

  • shiro

    You forgot to mention that it smells like rotten fish until you rinse it off…

    Konnyaku was pretty much my arch-enemy in school lunch until I got used to it. I still don’t enjoy it (I don’t enjoy many gelatinous things, even jell-o), but now at least I can eat it. My husband enjoys eating blocks of konnyaku sashimi with mustard. Smells horrible. :(

  • Robpoida

    Glad to know what this stuff is, finally. I’ve had in a bunch of soups and salads while I’ve been here, it’s heaps yum! And that’s also brilliant that it’s so healthy, an internal broom sounds like just what I need when it comes to what I’ve been eating in Japan.

  • Sakura

    I once tried going on a shirataki diet of sorts. When properly seasoned, the stuff is delicious, so I figured why not?

    The first day I only had it for dinner, but the next day I had it for lunch and dinner both. Spaghetti and alfredo! It was a great day! And then… things got really bad, really fast.

    I ended up having what can only be described as an emotional crisis. It’s very hard to explain, and I find myself laughing at the memory. It was that stupid!

    Basically, I felt very disconnected from myself, but at the same time, I knew that my existence was nothing more than a piss in the wind. I was fleeting as a vapor, good as dead already. Worthless. Pointless. The universe was a fathomless void, ready to swallow me whole.

    Imagine an entire night of that. It was horrible! I forgot all about my shirataki diet in the wake of that emotional turmoil, and I didn’t eat any of it for a week or two thereafter.

    It happened again the next time I ate shirataki noodles, but this time on a much smaller scale. I ended up getting my nutritionist involved, and she told me to stop eating the noodles! She told me that eating so much yam-based food was screwing up my hormone levels, giving me Super PMS From Hell. XP

    Soooooooooooo, enjoy these foods in moderation. Don’t be a dork like me!

  • Lloyd

    I pretty much eat it every day. I know the employees at the little Japanese grocery store think I’m nuts loading up on those noodles every week. When you’re cutting calories and going low carb, they make pasta meals possible.

  • Irochan

    I especially love konnyaku jelly! Goes very well with fruits for a yummy dessert.

  • jr

    I teach at schools here in Japan and had it for lunch just yesterday. A big pile of it as a side dish,not in soup or anything. I knew it was called devils tongue in English, but had no idea what it actually was. I’ve never had it anywhere else. My kids said it was very good for you.

  • kreebilicus

    It can actually be pretty dangerous, too! Fruit flavoured konnyaku is a popular snack, but it comes with a health warning on the pack urging people to chew it it properly. The reason for this is that konnyaku is firmer than gelatin and doesn’t melt at body temperature so it can easily get stuck in one’s throat and cause asphyxiation. Don’t get struck down by the Devil’s Tongue.

  • Inaripo

    Yesterday I made the grey stuff into a Japanese style curry using those curry blocks you can buy. The curry sauce is strong and the whole thing tasted great but I’m not sure the konnyaku took the flavour. I might try it with kimchi paste next or be braver and just with soy sauce.

  • Erika

    Konnyaku is good with gobo, carrot, chicken stirfry. Delicious. Still the texture is something to get used to.

  • Immapig-rawrr

    I saw on arashi’s tv show, when these celebrity wives went on their show, one of them made katsudon but put konnyaku inside the pork cutlet to cut down the calories! And they said you couldn’t even really tell it was there~ I wanna try it one day haha

  • Lee Hericks

    Well in a way it’s a potato.

  • Lee Hericks

    Here’s the thing. Konnyaku is amazing in nabe, oden, and other dishes. But to use it as a dieting tool can be extreme. Congrats on starving one’s body of nutrients. I’d rather eat Subway three times a day and still be getting proteins and vitamins.

  • John

    I for one would not enjoy the konnyaku diet. Eating only konnyaku would be a bit too extreme I think.

  • Genkakuzai

    Yeah I’m not a fan… that much is clear.

  • Tom

    Did you know…. (from the Lipozene website).

    What are the ingredients in Lipozene?

    Lipozene is made from the Konjac root, most commonly known as Glucomannan. This water-soluble fiber expands and acts as a dietary fiber gel in your stomach that helps you feel full, so you eat less and as a result, reach your weight loss goals quicker.

    This water-soluble fiber has been cultivated as a weight loss aid in Japan for generations. In fact, there are even studies that connect its main ingredient Glucomannan with alleviating constipation, reducing cholesterol and regulating blood sugar.

  • Ravi

    I am from India – down south. In our place, we called this root vegetable as “Karunai Kizhangu” in Tamil, in the North (India) they call “Sooran” in Hindi. We use this root vegetable in our food once in a while not that often, because of it itchy tongue if not cooked properly, some people do not know to cook properly. Most children won’t like this. If you taste this raw, your tongue will get itchy and won’t go for long time. Generally, after cleaning and removing the skin of the root, cut into small cubes and cook (boil) the pieces with tamarind till the cubes became soft. This process will remove the itchy elements. As per our Tamil cooking method, we smash (not too mushy) the cubes and add with our sauteed spices, onion and curry leaves. Also you can dry fry with spices with oil or you can make with tamarind sauce gravy type. All taste very good. In India we use this root vegetable (Konnyaku) for many centuries! I think it was banned in the USA for the sale of raw roots. You can find in any Indian store in the frozen section as “Sooran” raw cubes in a bag. Taro root is called as Seppan Kizhangu and also used in the same way. You can find recipe searching with Karunai Kilangu recipe Thanks.

  • Mindy L.

    What I’d really love to learn how to make are the noodles themselves. Is it possible to make them at home??