How Soy Sauce Has Been Made in Japan for Over 220 Years: An Inside View

Soy sauce has fig­ured into the cui­sine of east Asia for more than two mil­len­nia. By that stan­dard, the two-cen­tu­ry-old Fue­ki Shoyu Brew­ing has­n’t been in the game long. But in run­ning the oper­a­tion today, Masat­sugu Fue­ki can hard­ly be accused of fail­ing to uphold tra­di­tion: he adheres to just the same prac­tices for mak­ing soy sauce (shoyu, in Japan­ese) as the com­pa­ny’s founders did back in 1879. You can see the entire process in the Eater video above, shot at the Fue­ki fac­to­ry in Saita­ma Pre­fec­ture, just north­west of Tokyo. Fue­ki him­self guides the tour, explain­ing first the sheer sim­plic­i­ty of the ingre­di­ents — soy­beans, flour, and salt — and then the intri­cate bio­log­i­cal inter­ac­tions between them that must be prop­er­ly man­aged if the result is to pos­sess a suit­ably rich uma­mi fla­vor.

That we all know what uma­mi is today owes in part to the prop­a­ga­tion of soy sauce across the world. One of the “five basic fla­vors,” this dis­tinc­tive savori­ness man­i­fests in cer­tain fish, cheeses, toma­toes, and mush­rooms, but if you need a quick shot of uma­mi, you reach for the soy sauce. In bot­tles small and large, it had already become a com­mon prod­uct in the Unit­ed States by the time I was grow­ing up there in the 1980s and 90s.

It must be said, how­ev­er, that Amer­i­cans then still had some odd ways of using it: the now-acknowl­edged West­ern faux pas, for instance, of lib­er­al­ly driz­zling the stuff over rice. But wider aware­ness of soy sauce has led to a wider under­stand­ing of its prop­er place in food, and also of what sets the best apart from the mediocre — as well as a curios­i­ty about what it takes to make the best.

Fue­ki and his work­ers take pains every step of the way, from steam­ing the soy­beans to decom­pos­ing the wheat with a mold called koji to heat­ing the raw soy sauce in tanks before bot­tling. But the key is the kioke, a large wood­en fer­men­ta­tion bar­rel, the old­est of which at Fue­ki Shoyu Brew­ing goes back 150 years. Today, Fue­ki explains, few­er that 50 crafts­men in all of Japan know how to make them: hence the launch of the in-house Kioke Project, a series of work­shops meant to revi­tal­ize the craft. As he climbs down into an emp­ty kioke, Fue­ki describes it as “filled with invis­i­ble yeast fun­gus that’s unique to our place” — far from a con­t­a­m­i­nant, “the most impor­tant ele­ment, or trea­sure and our heart.” The care and sen­si­tiv­i­ty required, and indeed the indus­tri­al tech­niques them­selves, aren’t so dif­fer­ent from those involved in the mak­ing of fine wines. But it sure­ly takes a palate as expe­ri­enced as Fuek­i’s to taste “choco­late, vanil­la, cof­fee, rose, hyacinth” in the final prod­uct.

Relat­ed Con­tent:

Short Fas­ci­nat­ing Film Shows How Japan­ese Soy Sauce Has Been Made for the Past 750 years

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Based in Seoul, Col­in Mar­shall writes and broad­casts on cities, lan­guage, and cul­ture. His projects include the Sub­stack newslet­ter Books on Cities, the book The State­less City: a Walk through 21st-Cen­tu­ry Los Ange­les and the video series The City in Cin­e­ma. Fol­low him on Twit­ter at @colinmarshall, on Face­book, or on Insta­gram.