Monosodium glutamate–MSG–is the source of umami, that fifth taste we sense (along with with sour, salty, bitter, and sweet). It’s often describe as “meaty’ or “savory.” It occurs naturally in many foods, and in concentrated doses in things like red meat, seaweed, mushrooms, Parmesan cheese, and soy sauce, but it’s also been used for ages as a seasoning to wake up dishes that taste flat.
It’s a flavor enhancer, explains DanaB, used in addition to, or in place of, salt; if you taste a dish and it’s not really salt it needs, but something else you can’t put your finger on, MSG can brighten up its flavors. In powder form, it’s powerful stuff, and should be used very sparingly–no more than a sprinkle in most cases. Scott123 recommends measuring; he finds pinch dash smidgen measuring spoons, which are 1/8, 1/16, and 1/32 teaspoon measures, invaluable for working with MSG. Be conservative: you can add more if needed, but there’s no way to undo an MSG overdose. As Jackie de warns, “Watch out, too much and your dish can be ruined.”
Dana often uses a little sprinkle of MSG in guacamole when the avocados aren’t perfectly ripe or lack flavor. Jackie likes to add a little to eggs to boost their flavor. Scott123 avoids using MSG when cooking with foods that are naturally high in glutamates (e.g., tomato paste, Parmesan, heavily reduced meat stocks), but thinks it really enhances Tex-Mex dishes, chicken, and beans. He’d never dream of making chili without it, but only uses 1/4 teaspoon for an 8-quart potful.
MSG is a traditional enhancer in Chinese cooking. Some chowhounds avoid adding MSG to dishes that use lots of soy or fish sauce, feeling the combo can be overpowering. But plenty do use it, saying there’s a reason it’s been done for centuries. Fatty Lumpkin describes the way a pinch of MSG changed a bok choy stir-fry that had plenty of soy sauce but lacked that certain something: the MSG smoothed out and enhanced the flavor.
Some advocate reducing the overall salt in a dish when adding MSG, because MSG ups the sense of saltiness in food, and can lead to sodium overkill.
Look for MSG in Asian or Latino markets, where it will cost a fraction of the price of supermarket brands like Accent. bitsubeats likes Ajinomoto brand, and C. Hamster uses Sazon Goya.
As an alternative to MSG, Alice Letseat, says that a tiny bit of pure citric acid has much the same effect. Trader Joe’s sells citric acid, and it is also sold as “sour salt,” most often found in kosher shops or groceries with good kosher food selections. King Arthur Flour also sells it.
Using MSG in home cooking