Khao Niaw Dum — Black Sticky Rice Fermented / ข้าวเหนียวดำหมัก

Northern Thai and Isaan — rice fermentation is practiced throughout the Northern and Isaan regions; the black rice version is less common than the white rice version but shares the same technique

Fermented black sticky rice (for khao mak dum) is a lactic-fermented sweet made by steaming black glutinous rice, cooling completely, mixing with a rice wine starter (look pang khao mak), and fermenting sealed for 3–5 days. The fermentation produces a sweet, slightly alcoholic, tangy product — the starch converts to sugars and the lactic bacteria produce a clean, pleasant sourness. The result is eaten as a dessert or snack, served in its own sweet fermentation liquid. Unlike the black rice dessert cooked in coconut milk, khao mak dum is alive in the sense that it is an ongoing fermentation product.

Fermented black sticky rice's sweet-sour-slightly alcoholic character occupies a unique position between dessert and condiment — its natural sugars from starch conversion are sweeter than added sugar and its lactic acid more complex than lime.