Gamja-guksu

Hamgyong's high plateaus — Gaema, Jangjin, Bujeon — grow starchy potatoes in abundance, and the dialect word nongma means exactly that potato starch. During the early colonial period, Hamhung built up an industry milling the upland crop into starch, and a family of starch noodles grew from it; from these came both the broth-served nongma-guksu and the cold, fish-and-chili hoe-guksu that would be codified as Hamhung naengmyeon. Because the noodles can be pressed, frozen and then just blanched to order, they suited feasts and large gatherings, and the dish became standard banquet and holiday fare in the northeast.

Smooth, glassy strands with a remarkable bouncy chew — they resist the teeth and snap back rather than yielding softly. Almost neutral on their own, faintly earthy, they are a vehicle for the broth or dressing: in the hot bowl, warm and savory; in the cold version, slicked with sweet-hot chili and cut by the clean bite of raw fish.

Potato starch has no gluten, so it cannot be kneaded like wheat; instead the flour is scalded with boiling water (ikbanjuk), which gelatinizes part of the starch and binds the dough into something extensible enough to extrude. A little alum was traditionally added to firm and clarify the strands. Pushed through a press straight into boiling water, the noodles set almost instantly into a translucent, highly elastic gel — the springiness that defines them — and because they are starch, they cook far faster than wheat or buckwheat.