Chilled Tsukemen with Dipping Sauce That Clings Thanks to Natto Foam: Ryuji's Chilled Natto Tsukemen

They make two servings for the video, but Ryuji explains that you can think of the recipe as one bowl making one serving. First, put 150 cc of cold water in a bowl and add 2/3 teaspoon of chicken bouillon powder (Ryuji gets a laugh at one point by misspeaking and calling it "Hondashi"). This forms the base of the soup.

Next, add 2/3 teaspoon of Ajinomoto's iriko (dried sardine) dashi. According to Ryuji, iriko dashi is best, but kombu dashi or Hondashi will do if you don't have it. Even so, Ryuji says "iriko dashi is the tastiest," giving as reasons that it suits tsukemen and that it brings out a ramen-like quality for a proper flavor. Ryuji has been hooked on it lately and says it brings out the aroma of niboshi nicely.

Soy sauce: 2 and a half teaspoons. Using tablespoons makes it quite salty, so keep it to this amount. Add 3 shakes of pepper and 4 shakes of garlic powder. Fresh garlic is fine too, but in that case the flavor apparently becomes much stronger.

Mix these well until dissolved, then add 1 tablespoon of rice bran oil. If you're concerned about calories, half that amount is fine. Adding oil gives it a ramen-like quality. On the other hand, Ryuji also says that fats that solidify in a cold sauce aren't suitable. Finally, the key point is to get the sauce ice-cold, so put it in the fridge.

Ryuji divides the natto into two bowls so it's easier to see, but proceeds after noting that one bowl is actually enough. Ryuji uses small-grain natto because that's the only kind they buy, but recommends hikiwari (chopped) natto because it clings better.

Add the included sauce and mustard and mix. When a staff member asks, "The sauce doesn't really affect the flavor that much, does it?" Ryuji replies, "Actually, it does make a difference." The dipping sauce contains chicken and iriko dashi, and natto sauce packets usually contain bonito dashi. So the explanation is that you get to taste a triple dashi overall. People tend to leave natto sauce unused, but Ryuji says they usually use it all up in their own dishes, and that the mustard is fine to add as well since it makes a nice accent.

The talk about the sauce leads Ryuji to mention a post they saw on X (formerly Twitter) saying "natto sauce is bad for you." Some people say the sauce is unhealthy because it contains things like hydrolyzed protein and high-fructose corn syrup, but Ryuji denies this: "It's not bad for you." The speaker's view is that such people probably think anything chemically produced is bad for you. Ryuji adds that drinking a large amount would be the same as drinking juice, but that doesn't mean it would ruin your health.

From there, the conversation shifts to Ryuji's views on online debates. When Ryuji makes points like this, people say "Please don't stir things up," but Ryuji's view is that it's better to speak plainly to people who say wrong things. The person being told may never realize it. Even so, the people watching the exchange will think about which side is really off. Ryuji says that's what matters. However, Ryuji admits that the word "idiot" goes too far, and rephrases that what matters is telling them, "You're wrong."

What Ryuji positions as the biggest key point of this recipe is how the egg is used. Separate the egg into white and yolk, and first add only the white to the natto.

One reason is nutrition. With tsukemen, it's hard to get green vegetables or protein, but using eggs and natto lets you supplement protein. Ryuji says it would be perfect with a side of vegetables.

The other reason is texture. Many people dislike egg whites because they're slimy. But when mixed with natto, the natto's stickiness turns it into something like meringue. Ryuji explains that many people can eat it when it's meringue. The guideline for whipping is until it's fluffy and meringue-like. Use a whisk if you have one; if not, holding about five chopsticks together works as a substitute. In practice it foams up in no time, and the staff were surprised, saying "That's fast."

When a staff member asks whether the natto needs to be chilled, Ryuji answers, "It's better cold, but room temperature doesn't make much difference." As long as the soup is ice-cold, it's fine.

The conversation turns to wanting some vegetables, so they make "pan-roasted broccoli" with 200 g of frozen broccoli. Put it in a frying pan while still frozen and stir-fry with olive oil. Rice bran oil is fine too.

According to Ryuji, the advantage of stir-frying frozen broccoli is that the moisture cooks off. Frozen broccoli, which tends to turn soggy, ends up with a proper texture. When a staff member asks whether it's better to thaw it before cooking, Ryuji replies that thawing is a hassle and you're using heat anyway, so just stir-fry it as is. Ryuji shows that it gets browned even when cooked from frozen.

For seasoning: half a teaspoon of iriko dashi, a little soy sauce, and black pepper. Adding garlic flavor is also good, and Hondashi will do if you don't have iriko dashi. The speaker's standard is that it's delicious as long as it has a bit of umami. Quickly stir-frying frozen vegetables like this to eat alongside gives you an extra dish in no time. Since they were at it anyway, they decided to eat it chilled and put it in the fridge as well.

The Marutai Ramen is boiled first. Ryuji emphasizes how cheap it is, saying that even with somen, using Ibonoito costs about 100 yen per person, while Marutai is much cheaper. Marutai also doesn't release much starch when boiled, so you can boil the medium-thick noodles in the same water afterward. Conversely, if you boil regular Chinese-style noodles first, the flour comes out and the water turns thick. So if you're boiling both, Marutai goes first.

Ryuji also touches on calories. Marutai isn't fried noodles, so it's low in calories, at about 258 kcal for the noodles alone, and Ryuji says it's fine to eat two portions. On the other hand, the speaker explains that somen is higher in calories because oil is kneaded into it. Soba was also mentioned as a better option, but just as Ryuji began to touch on soba with a high buckwheat content and blood sugar, the conversation moved on to checking whether the noodles were done.

The boiling time is 3 minutes 30 seconds, and slightly firm is good. Ryuji says they're often asked questions about noodles like "Which is best?" and "Won't this one work?", so actually trying various things is a cooking researcher's job. Ryuji shows that the cloudy water after boiling can still be used, and then boils the medium-thick noodles for 3 minutes 30 seconds as well.

Another advantage of Marutai is its long shelf life, whereas fresh noodles generally last a few weeks. Ryuji does say, however, that fresh noodles are delicious in their own way.

Chill the noodles in plenty of ice water until your hands get cold. After that, squeezing them tightly is important. That's because any remaining water dilutes the sauce, and Ryuji explains that the dipping sauce was made on the strong side in anticipation of this.

For quantity, the medium-thick noodles are about 130 g per serving, while Marutai is 70 g per serving, so it's on the smaller side. Ryuji says this is because of Kyushu's kaedama (noodle refill) culture, so the portion assumes you'll get a refill. If you're using something like commercial-grade noodles, about 100 g is fine. For toppings, besides scallions, you can add anything you have, such as chashu or menma.

To finish, add the natto with the egg white to the chilled dipping sauce and mix, and it foams up all at once. Ryuji explains that it won't foam unless you first add only the egg white to the natto, which is why the white and yolk are handled separately. Finally, pour in the yolk and it's done.

The staff who tried it reacted with "This is way too good" and "This sauce is insane," praising how extremely well the natto foam clings to the noodles. Ryuji says they already knew it would go well with the medium-thick noodles, so what they were curious about was the Marutai. The impressions were that Marutai loosens up easily and doesn't become like somen, with a texture somewhere between somen and Chinese-style noodles, and that both have their merits.

On the doneness, Ryuji reflects while eating that "it's better to take them out earlier." Ryuji's take is that Marutai would probably have more chew if taken out at around 3 minutes and chilled.

As for the pan-roasted broccoli, a staff member described it as "tasting like it was stir-fried with anchovies." Someone also suggested that it might be tastier stir-fried from frozen. Asked whether stir-frying fresh broccoli would give the same result, Ryuji answered that it's a bit different. With fresh broccoli, the florets become watery.

As variations on how to eat it, adding okra was mentioned, as well as how scooping up the natto as you eat is a nice touch. Adding a little chili oil gives it a restaurant-like taste and fills in what was missing.

Ryuji also talks about the origin of this recipe. Around Shinjuku, there's a ramen shop that whips natto into a foam before topping the noodles with it—a natto tsukemen shop, so to speak. That one is apparently served hot, and this recipe is a chilled version of it. A staff member responded, "This is seriously revolutionary," and confirmed that it doesn't take much effort either.

Finally, Ryuji points out that natto and eggs are in most homes, and with just household seasonings beyond that, you can make it whenever the mood strikes. The noodles go well not only with ramen but also with soba and somen, and Ryuji wraps up by urging viewers to give natto-style tsukemen a try.