Umami Explained: Glutamate, Inosinate and Synergy

Umami gets described as “savouriness”, “the fifth taste” or, less helpfully, “that thing MSG does”. All three are true and none of them explains the most useful fact about it: umami is not one compound but a small team, and two members of that team together are far stronger than either one alone. Once you know that, a lot of Japanese cooking — and a surprising amount of our menu — stops looking like tradition and starts looking like chemistry.

This post is about that chemistry. It is not about smoke, which is a different subject; what charcoal does to food is covered in Charcoal 101.

Where the word comes from

In 1908 Kikunae Ikeda, a professor of chemistry at the University of Tokyo, set out to find what made kombu broth taste the way it does. He identified the answer the same year: glutamate. He named the taste umami, and a year later he and Saburōsuke Suzuki founded Ajinomoto to sell it as a seasoning, monosodium glutamate. That is the whole origin of MSG: a purified version of the thing that makes kelp stock taste of something.

Our matbucha post tells that part of the story at dish level, because the matbucha is built on a kelp-only dashi. What it does not get into is what happened next, which is where umami becomes genuinely interesting.

The second and third compounds

In 1913 one of Ikeda’s students, Shintaro Kodama, went looking for the source of savouriness in the other half of classic dashi, katsuobushi — dried, smoked bonito — and found a different compound: inosinate. In 1957 Akira Kuninaka identified a third, guanylate, which is especially abundant in dried shiitake.

Roughly, then:

Glutamate is widespread — in meat, fish and vegetables — and very high in kombu, ripe tomatoes, aged cheese and fermented soy products like soy sauce and miso.
Inosinate comes mostly from animal foods: meat and fish.
Guanylate is richest in dried mushrooms.

To give a sense of scale, a 2015 review by Kenzo Kurihara lists kombu at 1,200–3,400mg of glutamate per 100g, tomato at 150–250mg and cheese at 300–1,680mg. Kombu is, by some distance, the heavyweight.

The synergy, which is the part that matters

Kuninaka’s other discovery is the one that changes how you cook. Glutamate on its own tastes savoury. Inosinate or guanylate on its own is fairly weak. Put glutamate together with either of them and the result is not additive — it is multiplied.

The classic measurement comes from Shizuko Yamaguchi’s work in 1967: in human tasting, a mixture of glutamate and inosinate produced a response roughly eight times larger than glutamate alone, with the effect strongest when the two were in about equal proportions. The umami receptor itself, a protein pair called T1R1 and T1R3, was identified around 2002, and the human version shows the same synergy in the lab. It is not folklore. It is built into the tongue.

That is why classic Japanese dashi uses two ingredients rather than one. Kombu brings glutamate; bonito brings inosinate. Either one makes a decent stock. Together they make a much deeper one than the sum of the parts would suggest — and the Japanese kitchen worked this out by taste centuries before anyone could name the molecules.

The rule you can take home

Reduce it to one line: pair a plant or ferment with an animal. Something glutamate-rich (kelp, tomato, cheese, soy, miso) next to something inosinate-rich (meat, fish, cured fish) will taste more savoury than either would alone. A lot of dishes you already love follow this rule without announcing it: tomato with anchovy, parmesan on a meat sauce, a bacon-and-tomato sandwich.

Reading our menu with this in mind

We did not design the menu from a chemistry textbook, and we are not going to pretend we did. But read it with the glutamate-and-inosinate rule in mind and the pattern is hard to miss.

Kibbeh nayyeh — Margra lamb tartare with shio kombu. Lamb is an animal protein; shio kombu is salted, seasoned kelp. That is the dashi pairing in a completely different form, which is a big part of why the dish tastes fuller than raw lamb has any right to. The kibbeh nayyeh post covers the dish itself.

Habibi’s Brussel sprouts — with kinnogomadare, a Japanese golden-sesame sauce, and shredded bonito on top. The bonito is the inosinate half, sitting on a charred vegetable. Our sprouts post explains why reviewers keep calling it the dish to order; this is one of the reasons it tastes so much bigger than a vegetable.

The matbucha is the instructive exception: tomatoes and peppers with a kelp-only dashi. Tomato and kombu are both glutamate sources, and there is no bonito, so it is a glutamate-on-glutamate dish rather than a synergy dish. It is deep and rounded rather than meaty, and the difference is exactly what the chemistry predicts.

Fire-tossed edamame with shiro miso — a fermented soy paste, so a glutamate seasoning on a bean. We explain why miso instead of salt separately.

The roe. Ikura on the hummus and mentaiko and tobiko on the cassava and taramasalata put cured fish — an animal source — on top of chickpea and sesame. Our guide to Japanese roe covers the three.

Even dessert. The muhallebi carries a soy caramel made with Yamasa soy sauce. Soy sauce is fermented and carries free glutamate, which is part of why a soy caramel tastes rounder than a salted one; the muhallebi post gets into it.

This is also the clearest way to understand what the Japanese half of our kitchen contributes. Middle Eastern cooking builds savour from garlic, spice, smoke and time. Japanese cooking has a pantry — kombu, bonito, miso, soy, roe — that exists almost entirely to add umami without adding weight. How the two cuisines fit makes that argument at the level of the whole menu; this post is the reason it works.

A few honest caveats

More is not always better. Umami is a supporting taste. Push it too far and food tastes heavy and samey.
It needs salt to show up. Glutamate on its own, unsalted, is surprisingly flat; savouriness and salt work together.
Bonito is fish. If you avoid fish, the synergy dishes on our menu are exactly the ones to ask about, and our kitchen will tell you honestly what is in each one.

For the wider picture of Japanese cooking in Singapore, start with our full guide. For where the acid half of the menu comes from, see ponzu, explained, and for the question of whether any of this counts as authentic, we answered that too.

Habibi-san is at 29 Hamilton Road, Jalan Besar, open Tuesday to Sunday 5pm to 11pm, with weekend brunch 11am to 2.30pm. Every dish above is on the menu, and you can book a table here.

Sources

Ikeda, Kodama, Kuninaka, Yamaguchi’s 1967 synergy figure, the T1R1/T1R3 receptor and the glutamate contents of kombu, tomato and cheese: Kenzo Kurihara, “Umami the Fifth Basic Taste: History of Studies on Receptor Mechanisms and Role as a Food Flavor”, BioMed Research International, 2015. Ajinomoto’s founding and food sources: Wikipedia, Umami, and the Umami Information Center, “What is Umami”. All read 26 September 2026. Menu lines: the Habibi-san food menu PDF, checked unchanged the same day.