Pa-kimchi

Pa-kimchi belongs to the vast family of Korean kimchi, the practice of preserving vegetables in salt and seasoning that is ancient on the peninsula. As a named dish it is humble and undated, a home preparation rather than a courtly one. It is most strongly associated with Jeolla Province in the southwest, whose cooks are famous for a heavy hand with fermented anchovy and whose slender jjokpa scallions—the small, mild bunching onion, distinct from the thick daepa leek—are considered the proper choice. Cooks elsewhere make it too, sometimes with the larger daepa, though that version sours faster and is eaten younger.

Long ropes of onion, slippery with red seasoning, that you twist around chopsticks or drape over rice. Raw young, the allium is sharp and almost hot in the nose; well-fermented, it turns sour, funky, and deeply savory, the white root-ends staying crisp while the green leaves soften. Salty, garlicky, and unmistakably fishy from the anchovy sauce.

Fermentation is the engine. Salt and the salty fish sauce pull water out of the onions by osmosis and select for salt-tolerant lactic acid bacteria—Leuconostoc early, then Lactobacillus—which convert the onions' sugars into lactic acid, dropping the pH and preserving the vegetable while building sour tang. The anchovy sauce is itself a finished ferment: its proteases have already broken fish protein down into free amino acids such as glutamate, so it seasons the kimchi with concentrated umami from the first day. The glutinous-rice paste supplies starch sugars that feed the bacteria and helps the seasoning cling. Green onions are high in pungent organosulfur compounds (the same allyl sulfides as in garlic and leek); fermentation and time convert and mellow these, trading raw bite for rounded depth.