Building Umami: Glutamate, Synergy, and Layers

What umami is

Umami comes mainly from glutamate, an amino acid released when protein breaks down. So it is concentrated in anything aged, fermented, dried, or cooked a long time.

What "aged" and "fermented" actually do is cut protein up

An intact protein has almost no taste. Its glutamate is locked inside the chain, and the tongue only registers it once the chain has been cut and it is a free amino acid. So the list above is not "things get tastier if you leave them", it is a list of what cut the chain — and there is more than one way to do it.

• An enzyme made by a mould. In Miso a protease produced by koji spends a year cutting soybean protein apart. The mould itself finishes early and stands aside; the enzymes it left behind do the rest of the year.
• A bacterium. Natto works the same beans in three days, and makes something different out of them (below).
• The ingredient's own enzyme. Haring is gutted with the pancreas deliberately left in, and its digestive enzymes cut the flesh over three to five days. Nothing is added from outside at all.
• Alkali. In a Century Egg two months at high pH takes protein as far as free amino acids, some of which crystallise out on the white as needles. No enzyme and no microbe involved.
• Heat and time. A broth like Seolleongtang getting deeper over hours is the same job done slowly.

Put the other way round: an ingredient high in umami is usually one where somebody has already cut the protein up for you.

Add nucleotides (inosinate, guanylate) and the intensity does not add — it multiplies. That is umami synergy, and it is why unrelated cuisines arrived at the same pairings independently.

• Kombu (glutamate) + katsuobushi (inosinate) — Japanese dashi.
• Kombu + dried shiitake (guanylate) — vegetarian dashi.
• Tomato (glutamate) + meat (inosinate) — bolognese, ragù.
• Doenjang (glutamate) + anchovy (inosinate) — the base of Korean soups.
• Parmesan + pork — Italy.

Two ingredients that taste mild alone suddenly taste deep together. It is why Miso Soup and Doenjang Jjigae get so much from so little.

A substitution swaps one term, not one ingredient

The pairs above are written as a win: two mild things, deep together. Read as a product the same line says the reverse, and that is the half a cook meets more often — take one term out and what is left is not a weaker version of the same thing. Doenjang Jjigae puts it in those words while citing this guide: a doenjang stew made with plain water is "not a slightly weaker version of this; it is this with the multiplication missing."

And which term you are taking is usually settled for you. An animal ingredient dropped from a recipe is almost always the nucleotide — anchovy, katsuobushi, fish sauce, salted shrimp, dried flounder, a beef stock. What goes in for it is generally soy sauce or salt, which are glutamate and salt. So the swap leaves the term you already had and deletes the one that was multiplying it, which is why the savour comes out shallower and why more soy sauce does not bring it back.

• Put a nucleotide back, and there is essentially one of those that is not an animal. Kkakdugi replaces its salted shrimp and fish sauce with soy sauce and kombu and shiitake steeping liquid, then adds that "the savour is shallower, so a tablespoon of ground dried shiitake makes up the difference." Oi-sobagi does the same with a teaspoon, and Laap says outright that "swapping fish sauce for soy or salt costs you savouriness, so add a little dried shiitake liquid." All three reach for the same ingredient, and none of them tries to make it up on the glutamate side. The first line under "Umami without meat" below is that same pair written for building a dish from nothing; here it is a repair.
• Or stay on the animal side and swap nucleotide for nucleotide. Wonton Noodles cannot always get dried flounder, so it increases the dried shrimp and adds a little dried scallop — "less of that particular aroma, but the same direction of savouriness." The aroma changes and the term does not.
• Or make the swap at the level of the liquid. Francesinha's vegetarian version, common in Porto itself, puts mushroom liquor in place of the beef stock rather than working around a gap with seasonings.

A cook can also hold a term back deliberately, which only makes sense once the pair is read as a product. Shabu-shabu refuses katsuobushi: "this broth starts as kelp alone and the beef fills it in. Bonito at the start leaves no room for the meat." The kelp is the glutamate and the other term arrives later, out of the meat, in front of the eater — so bonito at the start is not an addition, it is the slot taken.

So the question to ask before a swap is not whether the two things taste alike but which side of the pair the one leaving was on. Fermented pastes sorts its own substitutions on a different basis and is right to: miso for doenjang, or gochujang for doubanjiang, is glutamate for glutamate, so what changes is salt level and direction rather than arithmetic. And Stocks and broths groups both kinds together in its no-time list because any of them lifts a flat pot; the question here is narrower, since you already have one term and have lost the other.

The case where the threads are glutamate

The sticky threads on Natto are not a polysaccharide. They are poly-glutamic acid — glutamate linked into a chain. The thing you can see stretching between the chopsticks is the amino acid this guide opened with, which makes natto an unusual case: not so much an ingredient that has umami as one where you can watch the material itself.

While it is still chained up, though, it does not taste of much. The principle above holds here too: the tongue needs it cut loose.

Cutting the protein up releases more than the part you taste

The routes above are all described by what they leave behind to taste. The same cutting has a second product, and it is usually the one people notice first: as the chain comes apart, some of its nitrogen ends up in compounds light enough to reach you through the air. A Century Egg uses that as its doneness test — "a sharp ammoniacal smell means the protein is being cut apart" — and the strong smell of Stinky Tofu is "volatile amines and indole compounds formed during fermentation". The smell is not something that happened beside the savour; it is evidence that the reaction this section is about has run.

Which agent did the cutting sets how much of it there is. Same bean: Cheonggukjang is given to a bacterium for two or three days and comes out "deeper and far more pungent than doenjang jjigae", while the doenjang beside it was cut by a koji mould's enzymes over a year under salt. Natto records the mechanism from its own side — it makes ammonia rather than acid, so its pH climbs to about 8. So the line this guide closes on, that a bean handed to a mould becomes miso or tempeh and handed to a bacterium becomes natto, is a statement about the smell as much as about the threads.

And then the two products part company, because only one of them is volatile. Glutamate is not going anywhere — nothing done in a pan takes it out. The smell can be sent away or held in, which leaves the cook a handle after the ferment is finished.

• Send it away. Stinky Tofu is deep-fried, and "frying drives much of it off … what stays behind is savour." Hongeo-hoe offers its steamed version on the same reasoning: heat drives a good deal of the ammonia off, which makes it the gentler way in.
• Hold it in. Cheonggukjang goes into the pot last and gets two or three minutes, because ten minutes of boiling "leaves only the stale note behind, not the nutty one" — so it is not one smell leaving as a block either; the part worth having goes first.
• Neither. Natto is wrapped in nori, which mutes it without touching the chemistry at all.

Two nearby things are different questions. Alcohol in cooking also drives volatile amines off, but those came out of raw fish or meat and nobody wanted them there; here they arrived with the savour and what is being chosen is how much to keep. And Fermentation basics reads a smell as a safety test rather than a flavour — which is why the same ammonia means ready in skate and spoiled in a crab, and as Hongeo-hoe puts it, the difference is where the nitrogen came from.

Where glutamate lives

• Fermented: soy sauce, doenjang, miso, fish sauce, shrimp paste, oyster sauce, cheese (parmesan especially), kimchi
• Dried: kombu, dried shiitake, anchovies, dried shrimp, sun-dried tomato
• Aged or cooked: aged meat, deeply browned onions, fried tomato paste
• Vegetables: tomato, corn, peas, cabbage, asparagus

In practice: build it in layers

A little of several things always beats a lot of one. Load up on one ingredient and you taste that ingredient; layer several and it just tastes good.

• Layer 1, the stock: kombu, anchovy, bones, dried shiitake. Ramen spends hours here. See Stocks and broths. Kombu's glutamate has a temperature attached to it: it comes out at 60-80°C and the sliminess and bitterness follow above that, which is why that guide treats the kombu line as a temperature rather than a time.
• Layer 2, browning: onions taken to brown, tomato paste fried dark. Frying the black bean paste for Jjajangmyeon is exactly this step — unfried, it tastes bitter and sharp.
• Layer 3, fermented seasonings: soy sauce, doenjang, fish sauce, oyster sauce. The doubanjiang in Mapo Tofu is this layer.
• Layer 4, the finish: sesame oil, nori, katsuobushi, grated cheese. Even a simple side like Eomuk Bokkeum gains a layer from sesame oil and seeds at the end.

The finishing layer is not only things you buy. Nori belongs here because algae are high in glutamate, and Lao Khai Phaen makes the same thing from scratch: Mekong river weed spread thin and dried into sheets. As the water leaves, the fibre surfaces bond into one sheet — and since the sesame and garlic are mixed in while it is still wet, the aroma ends up inside the sheet rather than brushed on it.

Browning is umami too

The Maillard reaction produces savoury compounds, not only aroma. So searing meat before a braise is partly an umami-building step — read it alongside Browning.

The extreme case in this direction is Doro Wat: a kilo of finely chopped red onion cooked with no fat at all for close to an hour, until it collapses completely. "Onions browned for half an hour or more" in the vegetarian list below is exactly this job, and with no flour, tomato or cream in the pot that onion becomes the body of the sauce.

There is also a place where the two routes meet. Dengaku takes miso made as above and puts it straight over charcoal. A year of fermentation has already left it full of free amino acids, so with sugar added and direct heat under it the Maillard reaction runs in about thirty seconds — a layer of browning laid on top of a layer of fermentation.

About MSG

MSG is monosodium glutamate: a purified form of chemically the same substance present in all the ingredients above. Extracted from kombu or produced by fermentation, the body cannot tell the difference.

Two practical things are worth knowing.

• It only supplies umami. Not aroma, texture, acid or fat. If a dish still tastes flat with MSG in it, what is missing is acid or salt — see Balancing flavour.
• It is not salt. Add MSG and remove salt and the dish tastes wrong. They are separate axes.

Umami without meat

Getting depth without meat is a matter of which ingredients you reach for.

• Dried shiitake soaking liquid plus kombu (the guanylate–glutamate synergy)
• Tomato paste fried until dark
• Onions browned for half an hour or more
• Doenjang, soy sauce, koji
• Toasted nuts, smoked paprika
• A parmesan rind (skip if strictly vegetarian)

That combination is why dishes like Chana Masala and Dal Curry taste as full as they do with no meat in them.

"Doenjang, soy sauce, koji" is written above as things you buy, but from the making side all of them are the first section of this guide.

• Miso — a koji mould's enzymes, over a year.
• Tempeh — a mould knits the beans into one slab with its hyphae, and while it does so its enzymes are cutting the bean protein too. That is why it tastes markedly deeper than boiled beans.
• Paocai — amino acids accumulate in the brine as lactic bacteria grow, which is why an old brine beats a new one.

One bean, several destinations: hand it to a mould and you get Miso or Tempeh; hand it to a bacterium and you get Natto.