Xian (鲜) is the Chinese concept that most closely maps to umami — though it encompasses more than the glutamate-driven savouriness that defines umami. Xian is better translated as 'fresh, vibrant, delicious' — it describes the quality in food that makes it taste alive and engaging, that makes saliva flow and the palate light up. It includes umami (the glutamate quality from soy sauce, oyster sauce, fermented pastes, and stocks) but also the freshness of perfectly cooked seafood, the brightness of fresh vegetables, and a certain indefinable vitality that great Chinese cooking pursues. MSG (monosodium glutamate, wei jing, 味精) — discovered by Japanese chemist Kikunae Ikeda in 1908 but rapidly adopted in Chinese cooking — is simply concentrated glutamate, a shortcut to the xian quality that traditionally required hours of stock-making or fermentation.
Sources of xian in Chinese cooking: (1) Glutamates from fermentation: soy sauce, oyster sauce, doubanjiang, douchi, fermented black bean — all are rich in glutamates from microbial protein breakdown. (2) Glutamates from drying and concentration: dried shrimp, dried scallop, dried mushroom — drying concentrates the free glutamates. (3) Stocks: a long-simmered stock extracts free glutamates (from proteins) and nucleotides (from bone marrow) — the combination of glutamates and nucleotides produces a synergistic umami effect far more powerful than either alone. (4) MSG: pure monosodium glutamate — used in small quantities (typically 1/4 tsp per dish) to amplify the xian quality of other ingredients. MSG is a naturally occurring compound — it is neither artificial nor dangerous in culinary quantities. The MSG rehabilitation: The 1960s American 'Chinese Restaurant Syndrome' attributed to MSG has been definitively disproven in double-blind studies. MSG is present in parmesan cheese, ripe tomatoes, and many other Western foods in quantities comparable to Chinese restaurant use.
Fuchsia Dunlop, Invitation to a Banquet (2023); Fuchsia Dunlop, Every Grain of Rice (2012)