One of the many interesting ingredients in the Japanese pantry is konnyaku — a versatile, low calorie food with a highly distinctive texture. It’s rubbery and springier than even finger jello¹.

Also called “devil’s tongue jelly,” konnyaku is more or less flavorless until it is simmered in broth, and so it is almost always part of a dish that has a flavorful broth or dressing. Besides soaking up the flavors of the broth, it provides an interesting textural element to stews and soups — for example, in the vegetable stew recipe below, you get soft vegetable, soft vegetable, soft vegetable, some fairly soft tofu, and then springy, resilient konnyaku.

The calorie label is a bit hard to believe: a 9 ounce (255 gram) package has only 30 calories, just 0.12 calories per gram, compared with a carbohydrate’s 4 calories per gram or a fat’s 9 calories per gram. The reason for this is fiber: the magic of konnyaku is that it form a resilient mass of fiber with nearly no starch, fat or protein.

Konnyaku is made from the root of the Amorphophallus konjac plant, which is peeled, boiled, and mashed, before a coagulant is added to cause the paste to set into a gel. Sometimes hijiki (a sea vegetable) is added for flavor, nutrition (calcium), and color. (The konnyaku in the photo above contains hijiki — the konnyaku noodles in the photo below do not.)

Konnyaku is Versatile

Konnyaku is sold in many forms.  The block is most common, but you’ll also find it in noodle form, which are known as shirataki (lit. “white waterfall”). The photo above shows a stew containing shirataki. Both konnyaku and shirataki can be found in the refrigerated section of Asian grocery stores, especially those with a Japanese specialty. (A cute picture of the konnyaku family at a Japanese web site shows its versatility.)

Konnyaku frequently appears in winter stews — the most famous one being oden — as it provides a dramatic contrast to ingredients which are soft from a long simmer. Oden appears in many kinds of restaurants and food stores: there are specialist restaurants with decades-old broth (see video below for details), but you’ll also find it in convenience stores in Japan (7-11, Lawson’s, Family Mart, etc.).

When I visited Japan in past years, something about the stew captured my attention, and I have tried many times to make a vegetarian oden at home. After many failures, I finally figured it out, thanks to Elizabeth Andoh’s invaluable Washoku. ². The combination of ingredients and cooking method create a stew that transports me back to Japan.

One of the beauties of the stew is that you can adjust ingredients as you see fit. No lotus root or burdock root? Leave them out and add some more potato or mushrooms ³. I haven’t tried green vegetables like snow peas or green beans, but it is conceivable that they would be tasty too.

My adaptation of Andoh’s recipe is below. But first, a video interlude.

Following Konnyaku To and From Tsukiji

Update, 1/13/19:  In each episode of the Trails to Tsukiji program on the NHK World network (which I receive via old-school antenna), a reporter investigates an ingredient, starting at the world-famous Tsukiji market, and working in both directions:  ‘upstream’ to its source (farm or sea) and ‘downstream’ to restaurants using the ingredient in traditional and modern ways.

This month, the featured ingredient was konnyaku, so the Trails to Tsukiji team spent about 30 minutes exploring konnyaku. After a quick introduction at the Tsukiji outside market, reporter Janni Olsson visited a long-established traditional restaurant that specializes in oden for her first taste of konnyaku.⁴

Next, she heads to Gunma prefecture to see how the yam that is turned into konnyaku is grown, and to learn an old fashioned way to make konnyaku from a yam farmer. The growing process is relatively complicated, since each yam takes two years to grow — a season in the field, overwintering in a slightly-heated warehouse, and then back into the field for another year before final harvest.

The most surprising part of the episode was segment at the Konnyaku Theme Park (!) in the Kanra district of Gunma. It’s primarily a place to promote traditional and new uses of the ingredient, with a free buffet of konnyaku-based foods, viewing ports into a working factory, cooking lessons for kids, and more. Konnyaku Park will definitely be on my ‘to visit’ list when I next visit Japan.

5 from 2 votes

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Japanese Vegetable Stew

A rich and hearty vegetarian stew with vegetables, tofu, and the interesting ingredient called konnyaku

Course Main Course

Cuisine Japanese

Ingredients

• 2 large carrots peeled and roll cut
• 3-4 Japanese sweet potatoes peeled and cut in odd-shaped pieces
• 3 waxy potatoes cut in odd-shaped pieces
• 2 inches burdock root a.k.a. gobo
• 2 inches lotus root peeled and roll cut
• A few mushrooms preferably shiitake
• 4 ounces deep-fried tofu
• 1 block konnyaku about 12 oz.
• 1 tbsp neutral vegetable oil
• 3/4 cup vegetarian dashi see recipe below
• 2 tbsp soy sauce
• 2 tsp sugar
• 1 tbsp sake

Instructions

Preparing the konnyaku

1. When you open a package of konnyaku, you will probably notice a somewhat funky aroma. Do not worry, this is not a sign of spoilage (assuming the konnyaku is opened before its sell-by date).
2. Rinse the block with clean water.
3. To make triangles, first slice it in half lengthwise.
4. Tip each piece onto its flat end and slice through the middle to make two thin sheets (you'll have four pieces now).
5. Next, use the tip of your knife to make shallow cuts into the surface of the konnyaku to provide additional surface area for flavor absorption.
6. After scoring both sides, cut the pieces in half lengthwise, and then into triangles. Do not stack pieces on top of each other as you cut, as they might slip as the knife applies pressure.

Making the stew

1. The first step -- and quite a fun one -- is to dry roast the konnyaku in a pan to remove excess moisture and thus allow it to absorb the flavors of the stock.
2. Heat a large skillet or wok over high heat.
3. When it is hot, add the konnyaku to the dry pan. Do not worry, it will not stick. Shake the pan to loosen the pieces and turn them now and then.
4. When the konnyaku starts to squeak, add the oil.
5. Stir fry the konnyaku for an additional 30 seconds, then add the vegetables.
6. Stir fry for a few more minutes.
7. Add the tofu and pour in the dashi (stock), soy sauce, sugar and sake. Stir the mixture.
8. Reduce the heat to medium-low. Cook, covered, until the vegetables are tender.

Serving

1. Serve with some rice, a salad, some Japanese quick pickles, and a nice saké.

Recipe Notes

Recipe inspired by Elizabeth Andoh's "Soy-Stewed Chicken with Vegetables" on page 254 of Washoku

Variation: You can also use shiritake, a noodle-like product made out of konnyaku. To prepare it, rinse it thoroughly after opening the package, cut the threads into shorter pieces if desired, then follow the same dry roasting process as for the konnyaku block.

Note: the roll cut is used to create uneven shapes that have extra surface area for flavor absorption or to reduce the chance of sticky during stir-frying. However, it also makes for vegetables that can be tough to pick up using chopsticks.

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Vegetarian Dashi Stock

A critical building block of vegetarian Japanese cooking, this stock is full of naturally-occurring flavor enhancers from kombu seaweed and shiitake mushrooms.  Ideally, the seaweed and mushrooms will soak for many hours, but that isn't essential. A decent stock can be made in a hurry.

Course Sauce

Cuisine Japanese

Prep Time 1 minute

Cook Time 8 minutes

Total Time 9 minutes

Ingredients

• 15-20 square inches kombu sea vegetable
• 2-4 dried shiitake mushrooms
• 4 cups cool water

Instructions

1. Place a piece of kombu sea vegetable and several dried shiitake mushrooms into the water. For best results, use a glass or ceramic container.

2. Let this mixture steep for a few hours or overnight in the refrigerator. A long soaking allows the natural glutamates (flavor enhancers) to develop and dissolve into the water.

3. When ready to make the stock, put the mixture in a pan over medium heat.
4. Bring it almost to a boil, then reduce the heat slightly to keep it at a low simmer. Keep it at this point for 5 minutes, then turn off the heat.
5. Let the mixture steep for 5 minutes more, and then strain into a saucepan.

6. Save the shiitake mushrooms for another use (recipes that call for dashi also often use shiitake mushrooms).  The kombu is often discarded, though there are certainly recipes that use it (see notes).

Recipe Notes

Kombu is available in many Asian grocery stores (generalists like 99 Ranch Market, and specialists in Japanese or Korean foods). Sometimes packages simply read "Kombu", sometimes they say "Dashi Kombu." 

The kombu is often discarded, though there are certainly recipes that use it:  Washoku has a one for a flavorful kombu relish; the team at Salt Point Seaweed recommend putting pieces in a pot of beans for extra umami (store the pieces of kombu in your freezer).

Adapted from Washoku: Recipes from the Japanese Home Kitchen, by Elizabeth Andoh

Originally published May 15, 2007.  Updated to fix broken links, reformat recipe, and describe the Trails to Tsukiji video.

1. Finger jello was not an uncommon offering at parties and potlucks in my youth in Michigan. I think it’s been several decades since I have seen it.
2. If you want to learn how to cook Japanese home-style food, buy the book.
3. The white-fleshed Japanese sweet potatoes sometimes called ‘Satsuma’ are especially good
4. The konnyaku and other oden ingredients are simmered in a broth that has been simmering for decades.  Like a sourdough starter, the restaurant staff adds additional water, kombu, bonito flakes, and other ingredients every day. In my post about the San Francisco’s Boudin bakery, I mention a oden restaurant in Osaka that has been has been continuously cooking their oden since 1897(!).