Agar-Agar Jelly

Stone flower seaweed (石花菜) has been harvested and traded along the Fujian and Guangdong coasts for centuries. The practice of dissolving dried agar strands in boiling water and cooling them into a gel was documented across the southern coastal provinces well before the twentieth century. By the early republican era, agar jelly was a fixture of Hong Kong street stalls and school tuck shops throughout the colonial period, sold in plain sugar, red bean, and coconut varieties. The dessert is known by distinct regional names across the Sinophone world: 菜燕 or 石花凍 in Taiwan, 石花凍 in Fujian, and 茉莉凍 in Zhoushan.

Silky and cool on the tongue, with a clean, faintly oceanic sweetness. The jelly shatters cleanly without the rubbery bounce of gelatin, dissolving almost instantly into a refreshing coolness—a texture that only agar, never gelatin, produces.

Agar is a sulfated galactan polysaccharide extracted from red algae cell walls. Unlike gelatin (which melts at body temperature), agar sets at roughly 35–40°C and does not re-melt below about 85°C, making it stable in hot weather. On cooling, the agarose fraction forms double-helix hydrogen-bonded networks that trap water in a firm but brittle gel, producing the characteristic clean-shattering bite rather than collagen-derived chewiness.