Tamari vs. koikuchi shoyu: the "drip from the miso vat" that survived only in Tokai

Set a bottle of tamari next to a bottle of koikuchi shoyu and the only visible difference is how dark one is. Have you felt that? In fact these two are fundamentally different seasonings, from the mix of raw ingredients to the way fermentation works.

And tamari production survives in strength almost only in the Tokai region: Aichi, Mie and Gifu. Why just there? Follow the reason for the difference and you arrive at the bottom of a miso vat.

The real difference is the mix of raw ingredients

Ordinary koikuchi shoyu (the standard dark shoyu) is brewed with soybeans and wheat in roughly equal parts. Wheat is what produces the toasty aroma and the lightness; you could call it the department of brightness in shoyu.

Tamari, by contrast, is brewed mostly from soybeans, with almost no wheat. The savory compounds released as soybean protein breaks down are packed in tightly, so the color runs dark, close to black, and the texture is syrupy. The scent is quiet, and the savor comes through all the more directly.

Both are called shoyu, yet a single shift in the ratio of ingredients changes the taste this much. The clean gloss and toasty note it takes on when heated are tamari's own as well.

It began as liquid pooling at the bottom of a miso vat

Behind this difference lies how tamari came about. Its origin, as it is told, was a byproduct of making miso. In a vat of miso brewed mostly from soybeans, liquid seeps out slowly during aging and pools, or "tamaru," at the bottom. Someone scooped it up, used it, and found a seasoning with a dense savor. That is said to be where the name tamari comes from.

Which means a culture of tasting the savor of soybeans in liquid form existed before today's wheat-using koikuchi shoyu was established. Tokai is the home ground of soybean miso, of which Hatcho miso is the emblem. Because a culture of brewing miso from soybeans alone had taken root there, the method for tamari, which lies along the same line, stayed deeply rooted in that land too.

200 years at the gate of the Ise Grand Shrine: Kojiya's "Ise Tamari"

One bottle carrying tamari culture into the present is "Ise Tamari" from Kojiya, in Ise, Mie Prefecture.

Kojiya was founded in 1816. On Kamiji-dori, the street at the gate of the Outer Shrine of the Ise Grand Shrine, it has gone on making tamari for over 200 years. In 1915 it exhibited at the Panama-Pacific International Exposition, and its tamari has been presented to the Outer Shrine at each Shikinen Sengu rebuilding. It is a maker that stands for Ise.

Picture Ise udon, the dish people eat on a pilgrimage to the shrine. That black, thick sauce over thick, soft noodles: tamari is what it is. Despite how dark it looks, it is not salty, and the savor of the soybeans spreads softly. The design of that taste, the one that surprises first-time eaters, does not work with anything but tamari.

How to enjoy tamari

• Sashimi: start with red-fleshed fish, tuna or bonito. The syrupy texture clings to the fish
• Ise udon at home: boiled udon, tamari, an egg yolk on top. The taste of the shrine-gate town, on your own table
• Teriyaki: heat brings out the gloss and the toasty note. Good on yellowtail or chicken thigh
• Sauce for mitarashi dango: tamari, sugar and potato starch make a properly toasty version
• Finishing a simmered dish: one drip at the end drops the floor of the savor a level deeper

Once you know how koikuchi and tamari differ, the bottle you choose changes how your usual table looks.

Frequently asked questions

What is the difference between tamari and koikuchi shoyu?

The biggest difference is the mix of raw ingredients. Ordinary koikuchi shoyu is brewed with soybeans and wheat in roughly equal parts, while tamari is brewed mostly from soybeans and uses almost no wheat. That gives it a dark color, a syrupy texture, and a strong savor drawn from the soybeans. The scent is quiet, and the savor comes forward.

What dishes does tamari suit?

The standard use is as a dipping shoyu for red-fleshed sashimi such as tuna and bonito. Heated, it gives a beautiful gloss and a toasty note, so it also goes into teriyaki, mitarashi dango and the sauce brushed on senbei. The black, thick sauce on Ise udon is based on tamari too.

If I am buying tamari for the first time, which one should I try?

"Ise Tamari" from Kojiya in Ise, Mie Prefecture. Founded in 1816, the maker has been making tamari for over 200 years at the gate of the Outer Shrine of the Ise Grand Shrine, and its tamari has been presented to the Outer Shrine at each Shikinen Sengu rebuilding. Pour it over boiled udon, top with an egg yolk, and you have something close to Ise udon at home.