Washoku, the Fermented Cuisine

the current — the mouth

Chapter Five — Dashi and Umami: Kombu, Katsuobushi, and the Discovery of Umami

第五章 — 出汁と旨味・昆布、鰹節、そして「うま味」の発見

Introduction — The Unseen Pillar Beneath the Subtraction

In the prologue, we called washoku a cuisine of subtraction, and said that beneath it lies umami. In Chapter Three, we saw the flesh-forsaking shōjin kitchen arrive at a dashi of kombu and shiitake. In Chapter Four, we saw the fish's protein, within narezushi, turn into umami. All these threads gather at one point. Dashi, and umami.

This chapter enters that core. The pillar that has upheld washoku's subtraction, unseen — that is dashi. And let us first confirm that katsuobushi, one principal of that broth, is in fact a fermented food made by mould.

I. Katsuobushi — the World's Hardest Fermented Food

Katsuobushi has two kinds: arabushi and karebushi. What divides the two is a single point — whether or not mould has been inoculated to ferment it.1

Boiled bonito, smoke-dried over a wood fire, is arabushi. This is not yet a fermented food. What may be called a fermented food is the karebushi beyond it — its surface shaved, mould inoculated, sun-dried.1 The mould used is a chosen, benign one called Aspergillus glaucus. It is kin to the very kōji that makes miso and soy sauce.2

This inoculation is repeated not once but twice, thrice, four times. The first mould, the second mould — they are grown, brushed away, sun-dried. What has been built up by repetition is called honkarebushi; its making takes nearly half a year.1 The mould draws the moisture out from within the katsuobushi. The honkarebushi thus thoroughly dried holds only about a tenth its weight in water. Here is why it is called "the world's hardest fermented food."1

The mould does more than harden. It breaks down protein to store the umami of amino acids, breaks down fat to make a clear broth, and fends off bad mould.3 The work of kōji we saw in miso and soy sauce is here cutting time into the flesh of a fish. Katsuobushi is the crystal of fermentation — a fish remade by mould and time.

II. Two Umami — Kombu and Katsuobushi

Washoku's dashi often joins two ingredients: kombu, and katsuobushi.

These two hold umami of different kinds. The umami of kombu is glutamate. A kind of amino acid, abundant in plant ingredients.4 The umami of katsuobushi, meanwhile, is inosinate. This is a nucleotide umami substance, abundant in animal ingredients such as flesh and fish.4 The umami of the plant, and the umami of the animal. Washoku has, within one dashi, made two things of differing nature meet.

III. Synergy — One and One Become Seven, or Eight

Why join the two? Here lies the deepest secret of washoku's dashi.

Join umami substances of differing nature — glutamate, and inosinate (or guanylate) — and the umami strengthens at a stroke, far beyond the mere sum of each tasted alone. The difference can be sevenfold, eightfold.5 This is called "the synergy of umami." The glutamate of kombu, and the inosinate of katsuobushi. The clear depth of washoku's ichiban-dashi was born of this multiplication.5

Here, an answer comes to the question left in Chapter Three. The flesh-forsaking shōjin kitchen, joining kombu (glutamate) and dried shiitake (guanylate), had drawn a deep dashi without the animal — that contrivance, too, was this very synergy. By crossing plant with plant, a full flavour is made without flesh. The shōjin cook knew this multiplication by the tongue, before he knew its reason.

And this wisdom is not Japan's alone. The bouillon of the West, the tang of China, join the glutamate of vegetables and the inosinate of meat.5 Humankind, long before it knew the word umami, had drawn this multiplication into its cooking as experience.

IV. Umami, a Discovery — 1908, 1913, 1957

When, then, did this experience become a word? Three Japanese, over half a century, unravelled its true nature.

First, 1908. Ikeda Kikunae of Tokyo Imperial University traced, from the broth of kombu, that the nature of umami was glutamate, and named it the fifth taste, "umami."6 Next, 1913, Ikeda's pupil Kodama Shintarō showed that the umami substance of katsuobushi was inosinate.6 And in 1957, Kuninaka Akira, at a soy-sauce brewing laboratory, found that the umami substance of dried shiitake was guanylate — and, with it, the workings of that synergy.6

Kombu, katsuobushi, shiitake — the three ingredients that have long upheld Japan's dashi. Their umami substances were each, by Japanese hands, given a word, one by one, across half a century. In 1985, by way of an international symposium, "umami" became a word shared by the world.6 Experience came first; the word caught up after. Washoku is what the tongue had known, and science at last explained.

Closing — Tasting Time, by the Tongue

Here, one notices a thing. Kombu, katsuobushi, dried shiitake — the ingredients of dashi are all things dried, or inoculated with mould, that have passed through long time. Raw, this much umami does not come out. Time raises umami within the ingredient.

That is to say: umami, pressed to its end, is the taste of time. The backbone this book set out at the start — that fermentation is a culture of eating time — takes, in this dashi, its clearest form. Within a single bowl of clear soup, we taste, by the tongue, many months of time.

It is the seasonings of the kitchen that bring this dashi to life in the everyday dish. In the next chapter, the watercourse descends at last into the kitchen. Sa-shi-su-se-so — that its very foundation of flavour, too, is for the most part fermentation, we shall confirm.

Sources

This text is the fifth chapter of a white paper on washoku. The facts set down rest on the cited sources. "Katsuobushi as a fermented food" refers to the mould-inoculated karebushi and honkarebushi, and does not include arabushi, which is not inoculated — a point stated plainly in the text. The dates and names of the discovery of umami rest on the sources. There are several theories as to Ikeda Kikunae's motive for the discovery, and this chapter relies on no particular anecdote. This chapter treats dashi and umami from the cultural and scientific-historical side, and does not enter into health effects.

Footnotes

  1. "The Basics of Katsuobushi," Minna no Hakkō Blend (on katsuobushi dividing into arabushi [smoke-dried, non-fermented] and karebushi [mould-inoculated = fermented], with what has been inoculated several times called honkarebushi, the making taking months, and the thoroughly dried karebushi being called "the world's hardest fermented food"). https://www.hakko-blend.com/study/hakkofood/09.html / "Katsuobushi: the World's Hardest Fermented Food?" Hakkō Biyori (on the first to fourth mould and sun-drying being repeated in the mould-room after smoking, karebushi and honkarebushi completing over four to six months). https://www.hakko-biyori.com/dictionary-43 ↩ ↩2 ↩3 ↩4

  2. "Is Katsuobushi a Fermented Food?" Yamaki (on the benign mould used for inoculation all belonging to the Aspergillus glaucus group, breaking down fat to bring out a refined flavour and umami, and preventing bad mould). https://www.yamaki.co.jp/katsuobushi-plus/news/202310_hakkou/ / "How Katsuobushi Is Made," Oku (on the shaved nodes being placed in a mould-room [25–26°C, 84–85% humidity] and the first, second and third mould inoculated to make karebushi and honkarebushi). https://www.oku1925.co.jp/product/ ↩

  3. "The Changes of Mould Inoculation," Ninben (on the katsuobushi mould using the moisture of the node's surface so that the core dries and hardens, and breaking down fat to make a clear, unclouded broth). https://www.ninben.co.jp/about/katsuo/kabitsuke/ / "The Basics of Katsuobushi," Minna no Hakkō Blend (on the chief component of katsuobushi being inosinate, and on the mould's protease breaking down protein to store amino acids such as glutamate, so that the synergy of nucleotide and amino-acid umami arises). https://www.hakko-blend.com/study/hakkofood/09.html ↩

  4. "The Secret of Umami Is in the Mould?" Amano Foods (on the chief umami substance of kombu being glutamate, an amino acid found in plant ingredients, and that of katsuobushi being inosinate, abundant in animal ingredients such as flesh and fish). https://www.amanofoods.jp/regular/mano/22093/ / "The Discovery of Nucleotide Umami Substances and Synergy," Umami Information Center (on glutamate being an amino acid while inosinate is a nucleotide substance). https://www.umamiinfo.jp/what/attraction/discovery/ ↩ ↩2

  5. "The Components of Umami," Japan Umami Seasoning Association (on glutamate combined with the nucleotide inosinate or guanylate making umami up to seven- or eightfold stronger than alone — "the synergy of umami" — and on Japanese cuisine joining kombu and katsuobushi, Western and Chinese cuisine vegetables and meat, having drawn on this empirically before its discovery). https://www.umamikyo.gr.jp/knowledge/ingredient.html / "The Secret of Flavour," Ajinomoto (on joining the glutamate of kombu and the inosinate of katsuobushi strengthening umami about seven- to eightfold). https://ajicollab.ajinomoto.co.jp/assets/img/material/pdf/information.pdf ↩ ↩2 ↩3

  6. "The Discovery of Nucleotide Umami Substances and Synergy" / "About the Umami Information Center," Umami Information Center (on Ikeda Kikunae naming glutamate from kombu "umami" in 1908, Kodama Shintarō finding inosinate in katsuobushi in 1913, and Kuninaka Akira finding guanylate in dried shiitake in 1957 and discovering the synergy). https://www.umamiinfo.jp/what/attraction/discovery/ / "The Three Great Umami Substances," Himeno Ichirō Shōten (on the discoveries of glutamate [Ikeda Kikunae, 1908], inosinate [Kodama Shintarō, 1913] and guanylate [Kuninaka Akira, Yamasa, 1957], and on "umami" becoming a worldwide word at the first international umami symposium in 1985). https://shiitake-himeno.co.jp/blog/2631 ↩ ↩2 ↩3 ↩4