MSG

MSG stands for monosodium glutamate. It is a fine white crystal, like salt, made of sodium and glutamate, the compound that gives tomatoes, Parmesan, mushrooms, soy sauce and kombu their savory depth. It adds umami, the savory, meaty taste, and makes food taste fuller and more rounded.

Why it works

Your tongue has receptors for glutamate. Foods rich in it register as savory. MSG gives you that compound in pure form, so a little goes a long way. It also lets you use less salt. MSG has about a third of the sodium of table salt by weight, and it boosts the sense of saltiness, so many cooks swap some of the salt for it.

How to use it

• Use it like salt, but much less. Start with about ¼ teaspoon for a pot of soup or stew that serves four, then taste.
• Add it to soups, broths, stir-fries, fried rice, dressings, marinades and dry rubs.
• Sprinkle a pinch on tomatoes, eggs, popcorn or fries along with salt.
• It dissolves easily, so you can add it at any point in cooking.

Used well, you do not taste MSG itself. The food just tastes more savory and satisfying. Used too heavily, it gives a flat, oddly sweet and mouth-coating taste.

Substitutes

Other glutamate-rich ingredients do the same job with more of their own flavor: soy sauce, fish sauce, miso, grated Parmesan, tomato paste, dried shiitake and kombu.

How to store it

Keep it in a closed container in a dry cupboard. It does not spoil.

Where it comes from

Glutamate was identified as the source of savory taste by the Japanese chemist Kikunae Ikeda in 1908, and he began producing MSG soon after. Today it is made by fermentation of starch or sugar, from sources such as corn, cassava or sugar beet, much like yogurt or vinegar. Food safety agencies, including the US Food and Drug Administration, consider it safe to eat in normal amounts. On European ingredient labels it appears as E621.