You’ve Probably Never Had Real Soy Sauce
I’d never even wondered what soy sauce was, really, until last summer, when I listened to Shunan Wang, the owner of Tea Drunk, wax rhapsodic about the complexities of the stuff, swooning over its citric notes as if it were a fine wine or whiskey.
At her beautiful shop in New York City, over tiny glasses of fresh Guapian, a green tea from Anhui Province, she regaled me with stories of the strange fermented delights she’d stumbled across during her adventures through China in search of tea: blocks of tofu inoculated with a mold that eventually left them swaddled in a mat of dense white hair. Fermented chili peppers fried into pancakes that you could only stand to eat a corner at a time, washed down with red hot swigs of baijiu, an incredibly high-proof Chinese liquor.
But what she really missed, she said, was soy sauce. When she was growing up in China, it was commonly brewed in small batches in her town. She said you could smell it just walking by: salty, a little alcoholic, pungent, and yeasty.
You can’t get it in the United States, she told me. I raised an eyebrow, thinking about how you might buy soy sauce basically anywhere you might buy a pack of gum.
In fact, according to a 2014 study, soy sauce is the third most consumed condiment in the United States — as American as ketchup and mayonnaise.
“No no no,” Shunan said. “Real soy sauce is fermented. All of those are made in a chemical process. They’re just like…salt.”
I later learned that much of the soy sauce found in supermarkets or at lunchtime sushi joints is made via a speedy three-day process called acid hydrolysis. After soybeans are pressed for oil, the remaining byproduct is boiled for half a day in hydrochloric acid — used mostly in industrial processes, say, for removing rust from iron or steel — until the protein breaks down into amino acids. The liquid is strained and clarified using more chemicals, then flavored with everything from citric acid to molasses, resulting in the inky brown substance we generally think of as soy sauce.
It is salty, shelf stable, and tastes pretty good, given the circumstances.
On the other hand, traditional soy sauce, invented more than 5,000 years ago in China, uses just five ingredients: soybeans, wheat, mold, water, and salt. Well, six, if you count time: It takes anywhere from a few months to five or more years for the proteins in soy to naturally collapse into flavorful amino acids, all the while collecting various strains of yeast and bacteria, and aging several seasons.
“I don’t think it would be so hard to try to make it on your own…” Shunan said, trailing off.
I’ve written regularly about Chinese-American culture and cuisine for years, investigating everything from baijiu to salted duck eggs; I’m even writing a cookbook about Chinese-American food with my friend, the chef Jonathan Wu. I don’t think of myself an authority on the cuisine, but I’m certainly conversational when it comes to the expansive landscape comprising both General Tso’s chicken and braised beef tendon.
You can imagine, then, how the conversation with Shunan dogged me like a playground taunt. You don’t know what real soy sauce tastes like. Given how essential the condiment is to Chinese cuisine across its diverse permutations, I felt exposed. Could I really know anything about Chinese food if I didn’t know the first thing about soy sauce?
Yet it wasn’t until I was elbow-deep in literature about soy and fermentation that it occurred to me there was another reason why the question felt so all-consuming. You see, ever since I was a child, my father, who immigrated to the United States during the Cultural Revolution, told me stories of my family’s life in Shanghai — we’d made a fortune off of soy sauce. We owned factories, then a wide network of shops, and, eventually, an entire town, just outside of Shanghai. But during the Cultural Revolution, everything was confiscated, everything lost.
It is a part of my family history that feels less elusive than the network of aunties and uncles I speak to infrequently on the phone, who live on the other side of the world, whose names, much less faces, are constantly slipping my mind. Looking at a bottle of soy sauce is just more tangible than a family history wrought with trauma and forgetting.
As the only American-born person in my family, I have always felt as though I’m the single person on the other side of a closed door.
We were like the Kennedys, Dad once mused while sitting back in a chair and recalling the family business. If it weren’t for the Cultural Revolution, he once said to me, you’d be like a princess. It always made me swell a little bit with pride to remember this, especially in my first years in New York when I felt deeply insecure, surrounded by colleagues with Ivy League educations, whose surnames could be traced back to famous intellectuals and cultural institutions. If they only knew, a part of me would think when I felt intimidated by their intellectual pretension, by their good diction. I clung to the stories of my family’s past, to their aristocratic trappings, hoping they might mean something about me.
And though I sensed there was something specious about my reliance on this belief, I had never really interrogated it until I found myself chasing that dream directly, saving a folder of tabs, hoarding screenshots culled from books, calling up old sources to chat about fermentation chambers and proper sanitization. It was simple: If I could just produce soy sauce, I could prove my direct link back to these upper-crust ancestors. I could prove to myself that I was really one of them.
Eventually, I cobbled together a recipe and enough equipment to produce 5 gallons of soy sauce. Then one evening last September, sitting at my kitchen table in my apartment in Brooklyn, I calculated a painstaking schedule that listed the exact weight, volume, temperature, humidity, and timing of each step of the process. I rose the next morning with the sun, disinfected my tiny kitchen, snapped on rubber gloves, and got to work.
Making soy sauce begins with a mold that develops like soft down on the surface of loosely packed steamed soybeans and cracked wheat. Aspergillus oryzae, commonly called koji, transforms what is otherwise a largely indigestible legume by digesting it into simpler components: starch into simple sugars, protein into amino acids. (The wheat is primarily a flavoring component.) Like any fermentation project, regulating temperature and humidity is crucial to the process.
Koji likes to live within about a 10-degree window, between about 85 and 95 degrees Fahrenheit at about 90 percent humidity. Wander too far outside of those boundaries and your koji dies. Time is also a factor: Grow the koji too fast, and the soybean mash won’t be properly inoculated by the mold. Grow it too slow, and you run the risk of bad bacteria or fungi infecting your mash: Staph or E. coli might overpower the “good” bacteria and enzymes that you are hoping to invite.
Guion, an old friend of mine visiting from Virginia, graciously agreed to help — he had far more fermentation experience than I did, having spent years brewing beer from homegrown hops, making sourdough, and brewing kvass from that bread.
Yet soy sauce was new for both of us, and because there were few references online, it felt like we were both venturing into the vast unknown.
“I don’t know, the mash seems a little dry,” he told me when he arrived, sticking his hands into my pot of steamed soybeans and roasted cracked wheat. We added hot water until the mash was steamy and the beans crushed easily between our thumbs. Together, we pressed the sandy beige substance into long plastic trays and used our fingers to draw furrows into it — more surface area for the koji mold to sprout. We arranged the trays in the warmest part of my apartment and were relieved to find that the room fell just within ideal range. But soon enough, as with any fermentation project, questions began arising that neither of us could have anticipated without having previously gone through the process.
For instance, one recipe advised covering the mash with plastic wrap to increase humidity, but Guion worried that the koji needed oxygen to grow. I imagined leaving the trays uncovered and inadvertently allowing wormy microscopic beings in.
“No, don’t worry. Once the koji is going, it’ll be strong enough to fight that stuff off,” Guion said, looking at me reassuringly as an image of squirming maggots played in my head. One thing that is often said about fermentation is that you often need to just go with your gut — so much about a bacterial process is variable depending on where you are, what the conditions of the day are like. But checking in with my gut, I felt only fear and a nagging embarrassment at embarking on this project at all — what was I doing?
“Let’s just go for it!” Guion said, and I attempted to absorb some of my friend’s courageousness as he unsheathed the trays. I grabbed a stack of kitchen towels, and as I smoothed them over the trays of now-uncovered mash, I told him what I knew about my family’s history in the soy trade, feeling proud to be finally taking part in an activity that so directly drew a line between myself and my past.
“Was the factory in Shanghai? Do you think you can find a recipe or something?”
“Huh,” I said, feeling stupid and sucker punched. “You know, I don’t really know. I don’t think my dad ever mentioned it.” My mind reeled to remember anything specific — What did the soy sauce taste like? Did the communists take the factory over or just destroy it? Were there still plants in production? Were there advertisements, branding, logos?
“Anyway,” I said, attempting to save face and avoid confronting ignorance. “I definitely want to try to track down the labels from the old soy sauce business. I just think it’d be really cool to make bottles and hand them out to friends, maybe even sell them.” I finished wrapping the last tray and stood up. Guion was studying the trays, his arms akimbo.
“I mean, that is, if this works out…” I looked at him and smiled, searching his face for reassurance.
By the next morning, the koji had begun to sprout into tiny puffballs, like snow flurries on a miniature landscape of beige soy and wheat. Guion and I marveled at our feat; I felt a little too lucky to believe it. The original directions instructed that we turn the mash regularly so that the koji had a chance to spread evenly throughout, so we spent half an hour or so that morning gently mixing the trays with our fingers and redrawing furrows. By afternoon, however, it was clear that the surface was losing moisture. If it did, the koji would die. We debated buying a spray bottle or massaging water back into the mash. We wondered if we might find a way to raise the temperature of the mash so the koji would grow faster.
“What if we put the trays in the bathroom with the hot water running?” I suggested, the idea seeming far-fetched even as I said it.
“Actually, no, that might be perfect,” he responded. “I mean, mold should be generating its own heat soon enough, so hopefully any bad bacteria won’t stand a chance so long as the koji is strong.”
I turned on the shower and gingerly stepped onto the toilet seat as Guion passed me the heavy trays, sliding them onto shelves that I normally used to store face masks and lipstick. Soon, steam billowed around me and my instant-read thermometer registered 90 degrees Fahrenheit and 85 percent humidity. Throughout the evening, we took turns checking on the trays and turning the shower on and off to reach optimal conditions, and by the next morning, were heartened to see a dense gray fur collecting on the surface of the mash. But by then, it was time for Guion to leave.
Alone again, I wondered what my ancestors might think of their great-great-great-granddaughter cluelessly attempting to recapture something of the family narrative.
But when I placed my hands on the thin plastic of the trays, heat radiated from them as if they’d just been pulled from an oven.
Standing there, I realized that, according to the plan I had written, I should have been turning the mash by now. But it didn’t feel right; my gut told me to leave the koji alone. It was doing just fine. Instead, remembering advice from a friend who makes sake, I opened the door to the bathroom to cut the heat and humidity, to encourage the mold to drive further inside the mash.
A week or so later, my trays were covered in a soft gray cloud that smelled sweet and complex, like hot chocolate. Some parts had even begun to spore in dark gray patches. I dug out a small corner of the mash and saw that the koji had permeated into the loosely packed soybeans, smelling sweet and a little sour. I made a solution of 14 percent brine and scraped the trays into a large pot with the solution, squeezing it through my hands until it turned into a thick beige sludge. I funneled the liquid, called moromi, into a 5-gallon carboy, covered the top with a thick muslin cloth and a rubber band, and proceeded to clean up my apartment, wondering what my life would look like in six months, in three years, in five.
My carboy of soy sauce sat in the corner of my kitchen. For a while, I studied it intently every morning with my first cup of tea, anxiously wondering week by week whether it was turning any darker, if it was fermenting or just rotting. I dutifully turned it with a wine agitator rod each week and stuck my nose into its spout to judge its developing nose. A few months in, I panicked when I saw that a lace-like mat had developed on its surface, but Guion told me it was just a common yeast that I could easily scrape off, just another sign of life. Fairly soon, though, the soy sauce receded into the background of my life, just a quirk in the landscape of my apartment. I stirred it when I remembered, but largely left it alone.
A few months later, I was home for Christmas, and asked my mother to sit down and help me trawl through Chinese Google results to see what facts we might learn about my family’s soy sauce factory. My father walked away as soon as I started asking questions — he’s never been one to dwell on the past. He shrugged when I asked about a recipe. When I shouted after him, about whether or not he could dig up the old labels, he looked at me, bemused.
“There weren’t labels!” he said.
“No labels?” I asked, confused.
“No,” he said, rolling his eyes. “You came with you own container to the store to fill up. What, you think we sold bottles of soy sauce? No!”
Ugh, I thought, my resolve only becoming stronger. I was certain my mother and I could dig something up on the Internet. But as we trawled through site after site that mentioned our surname in connection to the soy sauce trade, my mother began to realize that much of the information was hearsay from relatives who had been interviewed since the Cultural Revolution. And that information had been repurposed on countless blogs and websites. I slumped in my seat, knowing how unreliable that information could be. I started to give up hope and feel a little embarrassed. Maybe the family story was greatly exaggerated and I was just desperately clinging to romantic embellishment. Could it be possible that this entire project was just a testament to my own insecurity?
“Oh, a biography of your grand-uncle,” my mother suddenly said, clicking on a link. He had become a famous painter very late in life after aligning himself with the Communist Party. In his bio, she read a single line, mentioning that for most his pre-painterly life, he was well-off from living off his ownership of “a soy sauce factory.”
She grimaced. “He didn’t exactly own it. But okay, there, see?” she said. “At least there is official Chinese acknowledgement of the soy sauce factory.” If I felt relief, it was now only a small fraction of my brain, which was churning as I began to understand how much my own longing has amplified the story. No one had even been a part of the production for decades, my mother told me, much less my father.
“How did you figure out how to make your soy sauce, anyway?” my mother asked me, attempting to cheer me up. I explained the entire process to her, the trials of growing mold, of having to ferment something in my bathroom, of all places. “I bottled it three months ago,” I told her, recalling the simple joy of successfully growing the mold, feeling the koji-generated heat in my hands.
I hadn’t noticed that my father had reappeared, sipping a cup of tea. “Oh you still have so much time,” he said with a mischievous smile. “I just remember those vats of soy sauce. They always said for it to be ready, it has to age two summers, two winters.”
It’s said that the earliest one might taste naturally fermented soy sauce, to ensure at least that it hasn’t spoiled, is six months. I waited anxiously for March, and even when it came I was tentative. But on a listless morning that felt something like spring, I got up the pluck to stir my mash. It had probably been a month. By then I’d begun thinking of it purely as an object, like a mute pet that sat in the corner and needed only the smallest amount of maintenance. To think of it as anything else — much less something linked to my past — made me nervous.
But as I stirred, I pondered why I was so freaked out. What would it mean if I failed to make soy sauce?
Surely I’d already learned the hard truth: that there was no practical connection between myself and my family’s lost fortune.
Succeeding at making my own soy sauce wouldn’t prove anything about my heritage, just as my family’s past riches left no bearing on me, as much as, for a while, I wanted it to. You might say a generation of immigrants is, like koji, successful at alighting on a new place in diverse circumstances thanks to thousands of years of history, but as an individual thing, shaped uniquely by its present circumstances. Regardless of great trauma or glory, it would be disingenuous to believe otherwise.
If I had relied on anything, it was a history of thousands of years cultivating a brilliant hearty mold and its relationship to soybeans. But, as a yeasty dark aroma wafted up at me from the mash, I realized there was something about the mash before me that tied me to my family, something of which I have a right to be proud: the courage to invent something from nothing, to take a risk, to dream, to have faith.
I drew a taste of the moromi, careful to capture only liquid in my spoon. Salt was the first thing on my palate, then yeast. I closed my eyes and felt it coat my palate, the taste blooming in complexity — a little sour, then deeper and more buttery than its industrially made counterparts. There was a sweetness in its lingering aftertaste, nearly floral. I tried a little more and understood then that it was unmistakable. I had made soy sauce.
Wei Tchou is a writer in Brooklyn whose writing has appeared in The New Yorker, Esquire, and The Outline, among other publications. She’s currently working on a memoir about ferns.