This recipe, from chef Esther Choi’s grandmother, calls for a few crucial ingredients. It starts with sweet rice flour, which is cooked down into a kind of glue. This is used to thicken the chile paste—Choi advises never turning your back on it while cooking because it is prone to clumping and burning. Her recipe also uses plum extract, brined fermented Korean shrimp (saewoo juht), a good amount of shredded Korean dried pollock (bugeochae), and fresh scallions. The fermentation times listed here are the minimums required—you can let kimchi ferment for longer at room temperature if you desire a more sour taste and bubbly texture. The flavor will also continue to develop in the refrigerator, albeit much more slowly.