Chilled Somen Using Microwaved Mushrooms and All Their Juices: Ryuji and the Mushroom Doctor on Pre-Cut Mushrooms and the Effect of Rapid Cooling

At the start, the Doctor brought out cut king oyster mushrooms (80g) in renewed packaging. The bag features a character called "Eringi-kun," and Ryuji laughed that it was "not very imaginative."

According to the Doctor, both the cut buna shimeji and the cut king oyster mushrooms have had their stem bases removed, so they can be taken out of the bag and used in cooking as is. They can also be microwaved in the bag and frozen in the bag. When Ryuji checked that "it's said that freezing mushrooms makes them release more flavor," the Doctor explained that freezing breaks down the cells, umami compounds are produced during heating, and these are released more easily. Ryuji took this as a double benefit: keeping them in the freezer extends their shelf life and also makes them release more flavor.

What Ryuji particularly praised was that they can be microwaved. In summer the kitchen gets extremely hot, so being able to use the microwave makes things far easier. Ryuji's view is that in cooking, ease is the greatest benefit of all. He chose somen as something he wants to eat at this time of year, and said that because it pairs well with microwavable mushrooms, he made a somen dish that lets you eat plenty of mushrooms.

Before starting to cook, Ryuji offered the Doctor a drink. It was a barley tea made by HIKAKIN, with a picture of an oni on the bottle. After a toast, the Doctor commented that it "seems kind of toasty" and "the flavor feels rich too." Ryuji replied that HIKAKIN had been criticized by everyone for it being weak, but it isn't weak. Ryuji also said that this barley tea is delicious as a mixer for alcohol.

While cooking, Ryuji remarked, "I haven't really seen cut shimeji before." The Doctor replied that it is a product they are now in the process of expanding. The cut buna shimeji came first, and the king oyster mushrooms were added later. As for quantities, figures of "about 7,000 tons" for Hokto alone and "about 2,700 now" for king oyster mushrooms came up. However, it is unclear from the subtitles what quantity these refer to. On hearing these figures, Ryuji took it that there is considerably more shimeji.

When microwaving, make a small cut at the top of the bag. The Doctor warned that otherwise it will burst. The heating time is a minute and a half, and Ryuji explained that at 500W, about 2 minutes is a good guide. Mushrooms are an ingredient that can't be eaten without cooking, and until now the usual approach was to boil or stir-fry them, so Ryuji said being able to just use the microwave is great.

Add the following seasonings to the heated shimeji:

• Soy sauce, 1/2 tablespoon
• Olive oil, 1 tablespoon (for its aroma; rice oil or similar is fine if you don't have it)
• Hondashi, 1/3 teaspoon (to add bonito flavor)
• Shio kombu, 5g (about a pinch)
• Canned tuna, 1/2 can (you can drain the liquid, but it's fine to add it as well since it carries the tuna's umami)

What Ryuji emphasized most was the mushroom essence that collects in the bag. In his previous method, the mushrooms were boiled together with the somen, so their umami didn't come through. This time they are microwaved and their juices are eaten with the somen. He says this is extremely important. He also listed as an advantage that the Hondashi can be dissolved in while the liquid is still warm. Shio kombu has strong umami, and with bonito and kombu, a flavor like a blended dashi is created in the mix. Since the mushroom umami is layered on top of that, Ryuji described it as "triple umami."

After tossing and letting the flavors meld, chill it. Since you want to eat somen cold, if there's room in your freezer, putting it there will cool it quickly. If not, chill it in the refrigerator until cold. Along the way, Ryuji showed off the sheen of the shimeji and joked that thanks to appearing with the Doctor so many times, he can now tell freshness at a glance.

The packaging for the cut king oyster mushrooms used in the side dish says it contains "plenty" of a certain nutrient. According to the Doctor, this is a type of vitamin, a nutrient normally abundant in leafy vegetables like cabbage. King oyster mushrooms contain relatively large amounts of it, more than other mushrooms. Ryuji took this to mean that even though they're all called mushrooms, each has different nutritional value.

The Doctor went on to say that it would be even better to increase vitamin D by exposing them to ultraviolet light, and brought out a fluorescent lamp that can emit ultraviolet (UVB) light. Ryuji laughed, asking whether the Doctor kept an iguana or something, and pointing out that this was supposed to be a cooking video. According to the Doctor's explanation, it's better to open the bag, and exposing them to sunlight is another option. If you don't like using sunlight, you can use a reptile light, as introduced before. The Doctor also said that ideally, in the future, Hokto would be able to sell mushrooms that have already been exposed to UV. This was described as an idea, not something that has already been realized.

Ryuji considers small plates and side dishes very important in everyday meals. He says that lately, when he has the time, he introduces side dishes as well. As the reason, he cited the common complaint that side dishes are the biggest hassle to make, and said that at times like that, having pre-cut mushrooms is a huge help.

The method is simple. Make a cut in the bag of cut king oyster mushrooms and microwave for about 2 minutes. Add about 50g of frozen chopped okra and mix. Ryuji says he always keeps frozen okra on hand, and explained that the advantage is that you can mix in the frozen okra and eat it right away. The heat of the warm king oyster mushrooms thaws the cold okra, making it ready to eat immediately. He laughed that this method came from his own "lazy streak."

Essence also collects in the king oyster mushroom bag, so use it all. Finish with bonito flakes. Ryuji said that because of the king oyster mushrooms' umami, soy sauce alone is enough for seasoning. And so, a dish was completed in no time.

When Ryuji asked whether more kinds of cut products would be coming, the Doctor replied that they would like to do maitake too, but when sliced it falls apart and looks terrible, so it's difficult. Shiitake and the like would probably be possible. For now there are buna shimeji and king oyster mushrooms, and the Doctor thinks that if there are sliced products, it might also be good to freeze them as is while freshly made. Products that the manufacturer freezes immediately after production have been in test sales since last year.

It also came up that only the 80g product is microwave-compatible. Cut mushrooms also come in sizes such as 100g, 150g, and 300g, but those are not microwave-compatible. The Doctor said that might be something worth considering.

Ryuji added that you can make these without the cut products. With a cluster of buna shimeji, weigh out the amount needed, transfer to a container, cover with plastic wrap, and microwave. However, he noted that with king oyster mushrooms you have the extra work of cutting them yourself, plus transferring them to a container, so that part is a bit more of a hassle. He says the amount used this time corresponds to 1 to 2, about 2, king oyster mushrooms.

Here the Doctor revealed that the cut and regular products use different varieties. The packaged king oyster mushrooms introduced before are "Strain No. 10," but the cut king oyster mushrooms use "Strain No. 8." Cutting smaller king oyster mushrooms makes the pieces too small, so they choose a variety in which each one grows large. For cutting, fewer stalks are easier to handle, and they cut apart cleanly when run through the machine, making them well suited.

The buna shimeji are also a different variety; the cut version is "Strain No. 25." Shimeji sold in clusters use a variety whose cluster stays firmly attached, because it looks bad if it falls apart in the pack. For cutting, on the other hand, they choose a variety that comes apart when chopped through. When the actual products were placed side by side, the stem thickness was completely different, and Ryuji remarked that they looked substantial to bite into. The Doctor responded that a cooking method suited to each would be best. Ryuji said that since the only other topping in this somen is tuna, he thought the plump texture of cut shimeji would suit it, which is why he made this recipe.

Boil the somen in plenty of water. Ryuji uses hand-stretched somen, and cautioned that if you use somen that isn't hand-stretched, you should follow the package directions. Prepare ice water before boiling. Cold water is fine too, but in summer, ice water makes it even more delicious, he says.

Put 100g of somen into the pot as you would pasta, and boil for 45 seconds. Ryuji always recommends a 45-second boil, which leaves a firm core. He thinks this chewiness pairs well with the firm texture of the shimeji. Drain in a colander, rinse once with water to remove the sliminess, and soak in ice water for 1 minute. According to Ryuji's explanation, this lets water get into the somen, producing both a firm, chewy texture and the texture of being fully cooked. If you prefer it softer, boil for the usual 1 to 2 minutes. Finally, squeeze firmly to drain off the water thoroughly. The only flavoring needed is the delicious shimeji sauce, so don't leave any water behind.

When the mushrooms that had been chilling in the freezer were taken out, they were thoroughly cold but not frozen. According to the Doctor, mushrooms don't freeze that easily. Buna shimeji also contain a protein that makes them resistant to freezing. Enoki and nameko are even more resistant to freezing; because they are mushrooms that appear in the coldest part of winter, they produce substances that keep them from freezing, the Doctor explained. However, the Doctor added that this varies by type of mushroom.

Toss the somen with the sauce and top with shredded nori and chopped green onion to taste. Ryuji said that a little shichimi, if you like, makes the red stand out and gives it an appetizing color. With that, the Japanese-style mushroom somen was complete.

When they tasted it, the two first praised the chewiness. Ryuji said that normally he would add mentsuyu, but none was needed at all. He said the mushroom umami was quite strong, probably because the juices were used too, and the Doctor agreed. Ryuji noted that with things like mushroom ohitashi, the mushrooms are cooled in water after boiling, so the umami is lost, but this recipe is delicious because it uses the microwave.

Here the Doctor added that cooked mushrooms should be cooled as quickly as possible. If they stay warm and cool down slowly, their chewiness softens. Rapid cooling is the key, and the Doctor praised the use of frozen okra in the ohitashi to cool the king oyster mushrooms all at once as perfectly sensible.

Ryuji frankly admitted that he hadn't thought that far. He was convinced that the firm, chewy texture that had surprised him when he ate it was likely due to the cooling from the okra, and was delighted that the Doctor's addition made his case more than twice as convincing. Regarding the shimeji in the somen as well, the Doctor explained the connection between rapid cooling in the freezer and the way mushrooms firm up when cooled after cooking. Ryuji showed the bowl, saying "the shimeji are standing up on their own." The Doctor added that buna shimeji for cutting basically have thick stems, so they are sturdy.

The two also praised the somen itself highly. The noodles didn't stick together, each one standing apart, with a chewiness that had a firm core. The Doctor said this was the first time they had been able to feel the texture of shimeji this much, praised the contrast between the two textures, and said they would make it themselves. Ryuji reflected that both dishes this time made great use of the mushrooms' texture, so "I think I pulled it off this time." He also said that last time, the Doctor's recipe had gotten the better of him, so he had done his research.

The amount also came up. Using 80g of mushrooms for one serving is quite generous, but the two confirmed that one person can easily eat around 80g. According to the Doctor, within the company they talk about "eating one pack per person per meal." Currently, Japanese people eat less than 10g of mushrooms per person per meal, but 50g or 80g is an easy amount to eat, and the Doctor believes that with dishes like these it's entirely doable. Ryuji agreed that with this, he could eat as much as he wanted.

Finally, Ryuji mentioned that cut buna shimeji and cut king oyster mushrooms are sold in supermarkets nationwide, from Hokkaido to Kyushu, and encouraged viewers to try making the Japanese-style somen and the ohitashi. He also announced a campaign in which you can enter by purchasing Hokto mushrooms, and wrapped up the video.