MSG

• ajinomoto味の素

  Japanese

  A brand name — literally "essence of taste" — used generically in several countries. Ajinomoto is a company and MSG is the substance, and the two are not synonyms outside colloquial use.

• weijing味精

  Mandarin

  Literally "flavour essence". Also applied colloquially to chicken powder and other compound seasonings that contain MSG alongside salt and other ingredients, which is not the same product.

• mei jing

  Cantonese — Hong Kong and Guangdong

• micin

  Indonesian

• phong chu rotผงชูรส

  Thai

Savoury depth without a flavour of its own — the sensation of a dish having been cooked longer, reduced further or made with better stock than it was. On its own on the tongue it is faintly meaty and slightly salty and not pleasant. Its effect is entirely relational: it makes other things taste more like themselves.

White to off-white crystals, similar to coarse salt in appearance and readily mistaken for it in an unlabelled jar.

Fine to coarse crystals that dissolve readily in water and hardly at all in fat or oil, which decides where in a recipe it can go.

• Glutamate — The whole of the effect. The free glutamate ion binds umami receptors on the tongue, and it is chemically identical whether it arrives from a crystal, a tomato, a parmesan rind or a spoonful of soy sauce.
• Sodium — About twelve per cent of the compound by weight, against roughly thirty-nine per cent for table salt — the arithmetic behind using MSG to reduce sodium while keeping savouriness.

Dissolve it, add it with the salt, and use less than instinct suggests. MSG needs an aqueous phase — it does not dissolve in fat, so stirring it into oil achieves nothing — and it is heat-stable, so unlike every aromatic in this dataset the timing does not matter and it can go in at the start or at the end. Roughly half a teaspoon per portion is a common starting point, added alongside salt rather than replacing it, since the two are separate tastes and one does not do the other's job. The failure mode is overuse: past a certain concentration the savouriness stops increasing and a flat, faintly metallic quality appears, and that ceiling arrives noticeably sooner than salt's does. Where a dish is bland for want of aroma rather than for want of depth, MSG will not fix it and more of it will make it worse.

Anywhere savouriness is wanted and there is water for it to dissolve in: stocks, soups, braises, stir-fries, marinades, dressings, burger and sausage mixes, and dry seasoning for crisps, popcorn and chips. It works with meat, mushroom, tomato, cheese, seaweed and anything already savoury, because its effect is to amplify rather than to add. It works alongside salt rather than instead of it — the two are different tastes and each reaches a ceiling the other does not lift. What it cannot do is supply aroma, so it will not rescue a dish that is bland because it lacks spice rather than because it lacks depth.

• boiling — Stable. Glutamate is not volatile and does not break down at cooking temperatures, so MSG can go in at any point without losing effect — unlike almost every aromatic in this dataset, whose timing is the main thing to get right.
• frying — Does not dissolve in fat, so it needs an aqueous phase to work. Sprinkled onto a dry surface it stays a crystal until it meets moisture in the mouth, which is why it is used on crisps and popcorn and why it does nothing stirred into oil.

There is not one, and that is the honest answer rather than an omission. MSG has no aroma to check and no flavour that fades, so an old tub tastes exactly like a new one. If it has caked, break it up and use it.

• Caking or a solid block, which means moisture and not spoilage.
• Discoloration or clumping with off odours, which would indicate contamination from something else in the container rather than degradation of the MSG.

• There is essentially nothing to judge. MSG is a single purified compound and brands do not differ in composition, only in crystal size and price.
• Check that the tub is MSG rather than a compound seasoning: chicken powder, stock powder and "umami seasoning" often contain salt, sugar and starch alongside it.
• Buy from an East or Southeast Asian grocer, where it costs a fraction of what the same crystal costs in a jar marketed as an umami product.
• A "no MSG" claim on other products is about the ingredient list rather than about glutamate content, which may arrive as yeast extract instead.

Crystal size is the only grade, and it is a handling property rather than a quality one. Finer crystals dissolve faster and blend more evenly; coarser ones are easier to measure by eye. Nothing about the taste differs.

Tokyo, 1908, where Kikunae Ikeda isolated glutamate from kombu seaweed and proposed umami as a taste distinct from sweet, sour, salt and bitter. Commercial production began the following year, which makes MSG among the youngest seasonings in this dataset by a margin of centuries.

1. Fermentation — A carbohydrate feedstock — commonly cane molasses, tapioca or maize starch — is fermented by Corynebacterium glutamicum, a bacterium selected because it excretes glutamic acid rather than retaining it.Why: Producing glutamic acid biologically. This replaced the original process, which extracted it by acid hydrolysis of wheat gluten and is no longer used commercially.
2. Neutralisation — The glutamic acid is neutralised with sodium hydroxide to give monosodium glutamate, which unlike the free acid is highly soluble.Why: Solubility. Glutamic acid itself dissolves poorly, which is why the sodium salt is the product and not the acid.
3. Crystallisation and drying — The solution is decolourised, filtered, crystallised and dried to the familiar white crystal, then graded by crystal size.Why: A stable, free-flowing, uniform product.

Graded by crystal size rather than by anything sensory, because there is nothing sensory to grade — the compound is the compound. Fine crystals dissolve faster and are used in seasoning blends; larger crystals are easier to measure and are what a domestic tub usually contains.

The youngest seasoning in this dataset by a very long way. Kikunae Ikeda isolated glutamate from kombu at Tokyo Imperial University in 1908 while trying to identify what gave dashi its savoury quality, and named the taste umami. Commercial production began in 1909 and spread rapidly across East and Southeast Asia through the twentieth century, where it remains an ordinary domestic ingredient. Its reception in the West took a different course, and that divergence is more a story about food writing than about food chemistry.

Manufactured rather than traded as a crop, which puts MSG outside the spice-trade history that shapes almost every other entry here. Production is concentrated in East and Southeast Asia and is an industrial fermentation business rather than an agricultural one.