Warring States Survival Guide
Chapter 85 - 51: Already unable to continue understanding this world!

Chapter 85: Chapter 51: Already unable to continue understanding this world!

According to legend, during the Kamakura Era, a Japanese monk named Kakushin braved countless hardships and trekked all the way to China’s Jingshan Temple, known as "the foremost of the Five Mountains and Ten Monasteries," in search of Mahayana Buddhism. Whether he actually obtained the dharma or not is unclear, but the method of making miso—that is, fermented soybean paste—he certainly brought back.

Once he returned home, he gathered the monks and followers of his temple to start experimenting with making soybean paste, preparing for mass production as a capital base for supporting the dharma. But after the paste was finished, he discovered that the liquid floating on top—"shoyu"—was salty, savory, and surprisingly delicious. Thus, Japan now had soy sauce—also known as "shoyu" or "soy paste oil."

Of course, there are many other theories about the origins of Japanese soy sauce. Some say Kakushin failed at fermenting soybean paste, resulting in a vat of black water, and right as he was about to throw it out, felt it a shame and tasted it, accidentally discovering soy sauce. There are also claims that soy sauce was brought to Japan during the Tang Dynasty by Monk Jianzhen, or only introduced in the Ming Dynasty by immigrants, among many scholarly debates.

Now, it’s hard to say what the real story is. After all, before modern times, Japan didn’t have a tradition of keeping historical records, so after all this time, nobody can say for sure what really happened—or at least no one except for South Koreans, who are convinced that soy sauce was invented by Korea’s great inventor, King Sejong, and then passed on to China and Japan.

Anyway, that’s what they’ve always said online, and they’re probably about to apply for UNESCO heritage status too.

As for the traditional soy sauce brewing process...

The main raw materials are soybeans, wheat, and salt. Plant proteins from the beans provide the amino acids for the umami flavor; starches from wheat or buckwheat are converted into glucose for sweetness; salt brings the savoriness and also fights off unwanted bacteria so that fermentation can proceed smoothly.

Once the ingredients are ready, you move on to the koji making stage. First step: washing and steaming. If the soybeans don’t have enough moisture, the koji mold won’t grow; but if there’s too much water, quality tanks. So during the steaming, you need to keep a constant eye out. Usually, the soybeans need to be kept at about 47% moisture.

Once the beans are steamed, you dry-roast the wheat, mix it in, and then add the koji culture. Koji mold multiplies rapidly in heat, but the process demands lots of oxygen, meaning non-stop stirring—a really tiring job.

After the mold has finished multiplying, its hyphae start to grow and break down the soybeans and wheat.

This process usually takes three days. During this time the mold generates lots of heat, so you have to keep watching it and intervene as needed to keep the temperature below 40°C. Otherwise, you’ll end up with stinky natto instead of soy sauce—above 40°C, natto bacteria and other wild strains take over. But don’t drop below 24°C either, or the mold stops growing or just dies.

Once that’s done, you get "koji," and it’s time to add saltwater—how salty depends on the final product you want, but typically the amount is about 1.2 times the weight of the koji. (If you added salt grains instead at this point, you’d end up with miso.)

After adding the brine, you put the saltwater-koji mash into wooden barrels or ceramic vats to mature, which takes at least a year. But that doesn’t mean you just leave it alone—constant inspection, regular stirring, and adding air are crucial to keep the microbes alive.

The ancient brewer’s daily grind was really all about the question: "How do I keep these microbes alive and in a good mood?" There were tons of little tricks, like choosing barrels or vats, how often to stir in summer, whether to wrap the vats in straw during winter, stirring extra on rainy days, lowering the temperature when it’s too hot, and so on—the so-called "family secrets."

After a year, once the microbes are done, you can finally pour everything out of the vats, wrap it in cloth, and press it. The pressed liquid is raw soy sauce, full of various microorganisms. Then you heat it up to boiling, killing all the microbes, and that’s your finished soy sauce.

Ah Man probably doesn’t know all the nitty-gritty of soy sauce brewing, since her occupation is "Original Ninja," not Tibetan Craftsman, but she gets the general idea. She knows it’s tough work—it takes an entire year and lots of "family secrets," that sort of thing you pass to your sons but not your daughters. She thinks Harano’s plan to make money this way is absolutely delusional.

But Harano was too stubborn—he insisted on doing it, so there’s nothing she could do. She’d already stockpiled a stomach full of snarky remarks and was ready to nag him every step of the way, calling him a wastrel whose only talent was wasting things. But she hadn’t expected Harano to throw out the whole playbook, leaving her speechless and nearly giving her a stroke—she couldn’t understand at all what he was doing, it looked nothing like any soy sauce brewing she knew.

Harano first directed everyone to throw soybean cake, buckwheat hulls, and rice husks into several big vats, and added a ton of water. Then he poured in a little of some stinky liquid, and had the Momoi brothers wear masks and stir nonstop. Once it was all mixed, he had them move the vats onto an earthen stove to simmer with a low fire.

Everyone took shifts minding the fire to keep the temperature steady. After boiling for a full day and night—about twelve hours—Harano had the Momoi brothers take the vats down and let them cool to room temperature. Then he slowly poured in some strange medicine powder, and as he did, he kept dipping little paper sticks in and out, putting them into another liquid, and only stopped when the color on the sticks no longer changed.

Then, he announced the job was done. The vats were all covered and moved to the backyard for storage. After that, he was spaced out, mumbling things like "Dilute hydrochloric acid should be recoverable by steam condensation," "Corrosion on the vats is better than expected," "Neutralizing with native soda ash should work fine too," "Shouldn’t be enough to kill anyone, right," and other cryptic phrases. Then he disappeared into his room where nobody else was allowed, mumbling while sketching production equipment schematics—since this was just a trial run, mass production would require some purpose-built gear, like ceramic pipes and labor-saving stirrers and such.

Ah Man watched him leave, then stared at the vats left unattended in the backyard, scratching her head like mad.

What is going on—was this really soy sauce brewing?

No clue at all. She didn’t even get the ingredients—soybean cake, fine, but why so many buckwheat hulls and rice husks?

Is this stuff even safe for people to eat?

This can’t be right, can it?

She just couldn’t figure it out, so she went to look for Harano—but Harano was busy and didn’t feel like messing with her, just told her to keep an eye on those vats and call him if needed.

Not until the sixth day did Harano finally lift the lid and look inside. After thinking a bit, he called everyone over, wrapped the contents in cloth, pressed them, and boiled the liquid. They ended up with half a vat of brown-black fluid. Then he added half a vat of light brine, filling it all the way up again.

Ah Man hugged the vat and stared at it for a while, sniffed it, dipped a finger to taste, and fell silent—damn, it actually was soy sauce. Salty, a little sweet, very savory.

What the hell is going on?

Her whole worldview was shaken. Was the world always like this? Turns out, you don’t need a whole year to make soy sauce, you don’t even need soybeans or wheat—just a bunch of animal feed works? All these years, how did she never notice that!

For a moment, she felt her ten-odd youthful years had all gone to the dogs. Her brain was fried, nothing made sense, it was like some kind of Immortal Technique—totally beyond reason. And Harano, seeing her dazed, also hesitated but then dipped a finger to taste—his specialty was chemical engineering, and this process actually came from Japan. After WWII, Japanese people were short on grain and couldn’t brew soy sauce from beans, so they invented the dilute hydrochloric acid hydrolysis method, using soybean meal, wheat bran, and rice bran to make soy sauce.

The basic principle is dead simple: Soy sauce needs to turn proteins into various amino acids and starches into glucose. The old-school method uses all kinds of microbes to slowly break stuff down over a long time, and the conversion rate isn’t even that high. Modern Japanese, though, just use dilute hydrochloric acid to replace microbes and hydrolyze everything quickly—not only does it boost efficiency, but you can use raw materials that microbes wouldn’t even touch before, which saves a ton of food for people.

Lots of modern soy sauce factories still use this method, or some hybrid: Half fermentation, half hydrolysis. Because the old-school way just takes too long, and in today’s market, you’d get dunked on hard. Seriously, just check some soy sauce labels—they actually list hydrochloric acid as an ingredient (at least the honest ones do; some just skip it).

Of course, China mostly uses the "low-salt solid-state method" imported from the Soviet Union, which can make a batch in five days—a 7200% efficiency increase over traditional fermentation. But that method needs high-end equipment and huge factory space, way out of Harano’s league, so he figured the dilute hydrochloric acid method was the safest bet.

Slow, sure—takes seven or eight days, not as good as cranking out a batch in five, and productivity tanks. But for a down-and-out isekai traveler like him, this process is perfect—totally DIY-able.

As for where to get the hydrochloric acid—Japan has sulfur in abundance, so if you have sulfur and salt, just check an old high school chemistry textbook to see how to make sulfuric acid the "old-fashioned" way, then how to react it to get hydrochloric acid, then how to dilute it. Anyone with high school chemistry should manage.

Same deal for neutralizers—sodium carbonate for cleaning up hydrochloric acid residue and balancing pH. If you can find some native soda ash, just crack open the chemistry textbook and you’re set.

The other problems are the same—missing test tubes or reagents, just MacGyver something. Nothing Harano can’t handle.

Only, all these homemade chemicals just aren’t that pure, so the batch is bound to have tons of chemical residues. After dipping his finger in, Harano hesitated, not daring to put it in his mouth at first—should’ve tested on a chicken, a donkey, or something. Hopefully nobody dies from this...

Back in college, he’d only read old papers on this stuff in the library—this was his first time doing it for real, and the result made him anxious. But the more he thought about it, the more at ease he felt. Japanese folks in the ’50s and ’60s probably weren’t super picky, and they didn’t all drop dead—no reason he should. Plus, he was already eating salt with heavy metals off the charts, a little chemical residue in soy sauce shouldn’t matter.

With that, he decided to be the guinea pig himself, licked his finger, and slowly tasted the finished product.

Hmm... It really did taste like soy sauce. Not bad, actually—no weird aftertaste!

He looked toward the "well-informed local" to ask for her opinion: "Do you think anything seems off?"

Ah Man looked bewildered: "I don’t think... anything’s wrong. Just, the color’s a little too bright red. The soy sauce I’ve seen before was always darker, more murky."

In fact, the lack of anything wrong was what made this the most wrong—it took just seven or eight days to do what would’ve taken a Tibetan Craftsman a year, using leftover trash ingredients, and it even tasted fine. How could they possibly be okay with that!

Is this reasonable? No, it’s not reasonable at all!

She still didn’t get what the hell was happening. Everything in the world seemed absurd and twisted—her common sense completely corrupted by Harano, that eldritch horror. Harano thought a bit, looked at the color of the soy sauce, and guessed something went wrong with one of the heating steps—maybe not enough caramelization, but that could be fixed.

He grabbed a small jar, ladled two spoonfuls into the vat, stirred it, and turned to Ah Man: "How about now? Is the color right? If not, I’ll add two more spoons!"

Ah Man watched, seeing the soy sauce turn a bright brown, her brain buzzing—in fact, it had been buzzing this whole time, but now it buzzed even louder.

What? You can just adjust the color of soy sauce like that? How come she’d never heard of that?

Could it be, as the second wise man of Koka Life-saving Style, that she’d lived her whole life in vain? That she was just an ignorant nobody?

Her worldview was finally, completely shattered—Harano the eldritch horror had utterly corrupted her, and she could no longer make sense of reality!