NHK WORLD > JAPANESE FOOD > Special Features > Digging into the World of Mushrooms - Interview with Mushroom Explorer Dr. Etsuko Harada

Digging into the World of Mushrooms
Interview with Mushroom Explorer Dr. Etsuko Harada

November 12, 2018

As we feel the crisp, autumn air on our skin, the Japanese crave the aroma of wild mushrooms. Japan's love for mushrooms is deep, and goes way back to ancient days. Haiku written about mushrooms are found in the Manyoshu, the oldest piece of Japanese literature from the 7th century. Today, each Japanese family consumes about 12.8kg of mushrooms annually (data from Ministry of Internal Affairs and Communications).

Matsutake can be said to be the king of Japanese wild mushrooms, with its delicate, woody aroma, and sold at around 1,500 to 7,000 JPY per piece. Every fall, people go and search for matsutake in the mountains hoping to get a bite of this golden mushroom, or go splurge at high-end Japanese restaurants to eat them in a delicious dobin-mushi (a clear soup with mushroom, cooked in a miniature earthenware pot).


(Stock photo)

While most wild mushrooms can only be harvested in the fall, you can easily buy common, fresh mushrooms like shiitake, eryngii, enoki, shimeji, and maitake all year round for an affordable price in Japan. They are commonly used in nabe, soups, or oven dishes, and loved by people of all ages.

Left: Mushrooms sold at a Japanese supermarket / Button mushrooms, shiitake, eryngii, enoki, shimeji, maitake | Right: Different types of shiitake are sold according to cultivation method and location
Left: Mushrooms sold at a Japanese supermarket / Button mushrooms, shiitake, eryngii, enoki, shimeji, maitake
Right: Different types of shiitake are sold according to cultivation method and location

So why do the Japanese love mushrooms so much? To find out, I visited Dr. Etsuko Harada, the Head of the Iwade Research Institute of Mycology in Mie Prefecture.

Q: Thank you for letting us visit you. Can you tell us what you do at this institute and how you became interested in mushrooms?

Dr. Etsuko Harada
Dr. Etsuko Harada
Head of Iwade Research Institute of Mycology
Photo: Iwade Research Institute of Mycology

I have been surrounded by mushrooms since I was a child. I would help my family harvest shiitake they were growing in the back yard, although back then, I didn’t like eating them so much. I wanted to go into scientific research, so I attended agricultural college to study shiitake cultivation. The more research I did, the more I was drawn into the wonders and potential of mushrooms.

At this institute I’m researching ways to cultivate rare mushrooms and how to use them for medicinal purposes. I recently received a patent for developing the technology for the therapeutic use of himematsutake mushroom extracts to treat cancer. I’m also working with a pâtissier to develop sweets using mushrooms, to explore new, fun ways mushrooms can be used.

Q: Onto my main question. Why do you think the Japanese love mushrooms so much?

Dr. Etsuko Harada
Photo: Iwade Research Institute of Mycology

Mushrooms fit in so well with Japanese cuisine. They’re low in calories but filled with vitamin D, fiber, and umami, and can also lower your blood sugar level. People use dried shiitake regularly because its umami can’t be replaced by anything else.

But mainly, I think it’s because fresh mushrooms are widely available all year round in supermarkets here, thanks to the advanced cultivation technology that was developed in the 1920s. Mushrooms used to be picked in the wild, but now with cultivation they can be grown regardless of season. Currently 450,000 tons of mushrooms are produced annually, and Japan’s mushroom industry is a 200 billion yen industry.

Q: When did the first mushroom cultivation start?

It actually started 400 years ago in the Edo period. A charcoal producer named Genbei discovered that there was shiitake growing on the wood he was using to produce charcoal. Out of natural instinct, he wondered whether he could grow his own shiitake by cutting dents into wood with a hatchet. He then waited for shiitake to grow on it. Back then, they didn’t have the scientific knowledge of how shiitake grows (the mushroom hyphae land on a surface to grow mycelia, which then become mushrooms) – but he somehow guessed how to do it. And just as he thought, shiitake started growing in the dents, and this method was called “hatchet style cultivation”. This is how shiitake became more available to the public and eaten more often.

Q: How has cultivation developed since?

The method for shiitake cultivation didn’t really change much until the 1920s. The founder of our institute, Dr. Inosuke Iwade, succeeded in the first glass jar cultivation of shiitake in 1926, and this was a big breakthrough. Dr. Iwade played a significant role in educating cultivation methods through university lectures and his book “Mushroom Cultivation Technique”, which was read widely.

Another cultivation pioneer, Dr. Kisaku Mori, invented a technique called “tanegoma cultivation” in 1942. Until this technique was invented, farmers had to buy wood and wait for the shiitake to grow on them, so it was like a bet. If they were lucky, shiitake grew. But if not, they couldn’t make any money - so farmers desperately prayed to the wood, asking for shiitake to grow on them.

Surprised at this sight, Dr. Mori wanted to help. And after some intense research and years of trial and error, he developed tanegoma cultivation, which allowed farmers to manually plant wood chips cultured with shiitake mycelia, into the wood. Thanks to this technology farmers were able to make shiitake cultivation a business. Needless to say, Dr. Mori was deeply appreciated and respected by farmers. He went on to develop shimeji and nameko cultivation technology too, which created the foundation for the mushroom cultivation industry to boom in Japan.

Q: What kind of research do you currently do at your institute?

We research ways to cultivate rare mushrooms from different countries. We also cultivate different types of mushrooms to use for health and beauty products. Let me take you to the main building where the cultivation is done!

Mushroom cultivation room at Iwade Research Institute of Mycology
Mushroom cultivation room at Iwade Research Institute of Mycology

So here at this center we have about 200 types of mycelia, or the basic vegetative structure of a mushroom. We usually grow 10 kinds of mushrooms according to the environment they need. Mushrooms are really weak and sensitive. If they’re exposed to any kind of external bacteria at the initial stage of growth, they die. So we grow them carefully in a sterile environment, with care and love.

Sidenote: This is why you don’t have to wash mushrooms you buy in supermarkets – because cultivated mushrooms are always grown in a clean, sterile environment.

Q: What are the different stages of mushroom growth in cultivation?

We grow the mushrooms from mycelia. They then turn into primordia, then the fruit body, which is the part we eat. The fruit bodies then release hyphae, to start growth all over again.

So this is what mycelia look like. When I bring them back from a different location, I store the mycelia in a petri dish or a test tube like this, with agar. The agar keeps the mycelia alive and feeds them nutrients.

Mycelia of wild mushrooms
Mycelia of wild mushrooms

We then have to give the mycelia some stimulus. The ideal environment is different according to type. For example, with this mushroom called Coprinus, we cover the mycelia with soil and leave it in 25 degrees Celcius at 80% moisture to let it start growing into a mushroom.

Mycelia of Coprinus
Mycelia of Coprinus

Q: Why do you need to give mycelia stimulus?

The mycelia won’t create the fruit body unless there is external stimulus. So mycelia don’t grow into a mushroom if they just sit there. When the mycelia are covered with soil, they take it as a stimulus and start climbing up to the soil.

Stimuli like soil, moisture, or temperature make the mycelia sense some danger, which then makes them grow and change into a reproductive state. This is an innate reaction to preserve their DNA and reproduce offspring.

Q: So the mycelia change into a reproductive state. And that’s what makes them start growing into a mushroom?

Right. When mycelia reach the surface of the soil they then grow into a primordium, which is the baby stage of the mushroom, as you can see here.

Primordia of Coprinus
Primordia of Coprinus

Then, as the primordia continue to grow, they form the fruit body. Now they’re ready to be picked, and ready to release hyphae (invisible to the eye). When the hyphae hit the soil, they transform into mycelia and the growth cycle starts again. This cycle can continue for about one to three months, and until the fruit body stops growing.

Coprinus fruit body
Coprinus fruit body
Photo: Etsuko Harada

Q: This is so fascinating. Can you show me some other mushrooms?

These are called Reishi mushrooms. The surface is hard, and shaped like a kidney. For over 2000 years, Reishi have been cherished in Chinese medicine as a nutritional supplement, but lately they’re also used for cancer treatment. Reishi like warmer environments so we set the temperature at 30 degrees Celcius.

Reishi mushrooms
Reishi mushrooms

Unique Gifts of Nature

The tour of the cultivation facility showed me that the abundance of mushrooms in the supermarket today is all thanks to innovative researchers like Dr. Harada and her predecessors.

After a tour of the institute, Dr. Harada was kind enough to prepare me a meal of mushroom rice and soup, using three kinds of mushrooms. She had just participated in a mushroom exhibition event in Nagano Prefecture, and had brought home some wild mushrooms. The rice was made with ohichotake from Mie, and the soup used amitake from Shiga, and hanaiguchi and kuritake from Nagano.

Amitake, kuritake and hanaiguchi soup / Ohichotake rice
Amitake, kuritake and hanaiguchi soup / Ohichotake rice

Hanaiguchi, ohichotake, amitake and kuritake
Hanaiguchi, ohichotake, amitake and kuritake

The first thing you notice when you take a bite of the ohichotake rice is its soothing aroma. Ohichotake’s texture is like eryngii, and the more you chew, the tastier it is. The amitake, hanaiguchi and kuritake soup bursts with umami, and has a nice, slimy texture. Both the rice and soup use konbu kelp and bonito broth as the base, with a hint of light soy sauce.

“I combined three mushrooms in the soup to bring out more of the glutamic acid and glutamic acid from each other, and you get stronger umami. These mushrooms are only found once a year in specific areas. It’s really exciting when you find them out in the wild,” explained Dr. Harada.

Ohichotake is cultivated in the wild, but can’t be cultivated indoors; and neither amitake nor hanaiguchi can be cultivated artificially. Only found in nature, the scarcity makes wild mushrooms like these so precious.

The Decline of the Matsutake

In fact, Dr. Harada says, matsutake is another wild mushroom that is so precious, but declining in number because of environmental changes.

Matsutake growing in the wild
Matsutake growing in the wild
Photo: Etsuko Harada

Matsutake are symbiotic with pine trees, so they can only grow where pine trees grow, and the surface of the soil also has to be clear of leaves. But lately, disease and insects are killing pine trees, and less people are taking care of the mountains, which makes it harder for matsutake to grow.

Back in the Edo period, people took good care of the forests, making sure weeds and foliage were cleared. That created soil ideal for matsutake. But now, with the decline of the timber industry, forests are left untended, so the soil isn’t ideal for matsutake to grow. Nature needs the careful attention from humans to maintain its balance.

***

Both cultivated mushrooms and wild mushrooms need special care by humans to grow at their best. When care is given in the mountains, the mountains provide rich bounties like matsutake in return. Even with cultivated mushrooms, the mushrooms can provide the therapeutic care for diseases. In a sense, humans and mushrooms are also symbiotic.

In Search of the Gargal

Other than being a mushroom expert, Dr. Harada is also a “mushroom ambassador”. She travels around the world from Africa to South America to teach cultivation methods, and brings home the mycelia of exotic mushrooms for cultivation.

One mushroom called Grifola Gargal is very special to Dr. Harada. It is native to South America, and grows mainly in the Patagonia region, deep in the primeval beech tree forests. Gargal mycelia have a sweet aroma of apricot seeds. It is a very rare wild mushroom that only grows in May, and is sold at a high price as a luxury food. But only the indigenous Mapuche tribe of Chile know where they grow.

Grifola Gargal
Grifola Gargal
Photo: Etsuko Harada

Q: How did you first hear about Gargal?

From the years 2000 to 2002, I was a volunteer researcher for JICA (Japan International Cooperation Agency) in Chile, where I taught mushroom cultivation techniques. One day, the local researcher I was working with told me about Gargal. I was curious to go see this rare mushroom in the wild, but nobody knew exactly where I could find it. Then I heard it takes a good seven hours by bus to get to where they grow, but every time I went, I couldn’t find any – they grow in random locations, and they’re just really rare.

My term with JICA was about to end, so I extended my stay for three months. And finally, in May of 2002, guided by a Mapuche tribal member, we found a big root of Gargal sitting quietly among the misty fogs, emitting a sweet apricot scent. That’s when I fell in love with Gargal.

Grifola Gargal
Grifola Gargal
Photo: Etsuko Harada

Q: You are now the first person in the world to successfully cultivate Gargal. How did you achieve that?

The following year I started working with the Iwade Institute of Mycology, so I travelled to Chile again – this time to bring back home the mycelia of Gargal. I only had two weeks to go find this rare mushroom, but this time it was even more complicated.

I had to wait until I was sure that Gargal was in season – and one day the local guide called me from Chile to say that he saw some Gargal in the forest. So I immediately booked my flight, and once I arrived I spent ten hours (on horse!) to go and see the Gargal - but what the guide showed me was a totally different mushroom! It turned out he didn’t have much knowledge about Gargal.

Q: You must have been devastated. So what did you do?

I was ready to give up, but as we were headed back to the hostel, I saw a lumberjack who was chopping wood. I told the guide to go ask him if he knew anything about Gargal. Then, the lumberjack said, “My wife actually just found three big Gargal roots, and is about to take them home. Let me take you there.” I couldn’t believe it! So our horse followed his horse, and we were finally able to find Gargal in the middle of nowhere.

Local guides (right and left) and Mapuche lumberjack (middle) with the Gargal
Local guides (right and left) and Mapuche lumberjack (middle) with the Gargal
Photo: Etsuko Harada

Q: So this time did you get the mycelia of the Gargal?

Yes! I safely returned to Japan with the Gargal mycelia. And after years of research, I became the first in the world to succeed in its cultivation.

Dr. Harada with Gargal mycelia
Dr. Harada with Gargal mycelia

Q: So now that you can cultivate Gargal, what are you doing with it?

Just this summer, I received a grant from The Small and Medium Enterprise Agency for a project to pass on the Gargal cultivation technology to the Mapuche tribe. With this technology, they will be able to grow Gargal on their own, and make a living from it. I work closely with the Chilean government so Gargal can help build their economy. Just this October, the Foreign Minister of Chile requested to meet me when he was visiting Japan, so we did! He’s a strong supporter and believer in this project, which is very exciting.

I’ve also developed a soap made of Gargal extracts and shea butter. It makes your skin really soft and smooth! Here, you can have one!

Soap with Gargal extracts
Soap with Gargal extracts

Q: Thank you! You’re changing the world with mushrooms. Tell me about your vision.

The research I’ve been doing is all thanks to the global experience I had in countries like Chile, Ghana, and China. Now that I have a good foundation for my research, I want to be a bridge between cultures and countries. I hope to give something back to society, whether it be through teaching cultivation technology, or helping people improve their lives with mushrooms.

****

Dr. Harada’s fascinating mushroom journey continues. Until I met Dr. Harada, I had no idea that the world of mushrooms was so deep – mushrooms are not just closely linked to Japanese people, but to the world, and have the power to enrich people’s lives from the ground up in the shape of food, medicinal products, and beauty products. Oh, and that soap, by the way, made my facial skin as soft and shiny as a boiled egg.

In Part 2 of this article, we’ll take a look at how Dr. Harada is now developing dessert recipes...using mushrooms!

Text and Photos: Mirei Yamagata

Special Features