Put Chai Ko

Put chai ko originates in Taishan (台山), an emigrant county of Guangdong, and is said to be recorded in the Qing-dynasty Taishan county gazetteer of the Xianfeng reign (1851–1861), with an account of a maker who washed his sugar in clear spring water seeping from a riverbed stone before steaming the batter in bowls (钵), though this is hard to verify. The Taishan original used only rice flour and came in plain brown-sugar and white-sugar forms. The exact inventor is unrecorded. It was Hong Kong, however, that turned the cake into a famous street snack and multiplied its flavours, with its peak popularity in the 1980s and 1990s; the 1993 film 《新不了情》, which featured a put chai ko hawker, is widely credited with fixing it in the city's memory. The name simply means 'little-bowl cake' (砵仔 = a small bowl); the stone-radical 砵 is the more fitting character since the cake is set in an earthenware or porcelain vessel, though the metal-radical 钵仔糕 is the commoner spelling and 缽仔糕 the Hong Kong traditional-character form.

Turned out of the bowl, it is a squat disc that the bamboo skewer lifts cleanly. The crystal version is glassy and semi-translucent with red beans suspended in it; the old style is opaque, ivory or amber. The mouthfeel is the whole point: smooth and springy with a real chew, yet — done right — it does not stick to the teeth (不粘牙), and warm from the steamer it eats soft, slick and fragrant. The brown-sugar cake carries the slight molasses depth of slab sugar; the red beans break the sweetness with their soft, mealy bite. A bad one is either gummy and tooth-clinging, or hard with a sunken dimple in the middle from raw starch that never properly set.

Texture comes from how the starches gelatinize. Rice flour is relatively high in amylose, which gives a firm, opaque, glutinous body — the old-style cake; tapioca starch and wheat starch (澄面) are higher in amylopectin and set up clear and springy, which is why the crystal versions are translucent and bouncy. The signature trick is the part-cooked slurry: rather than pouring boiling sugar-water straight onto raw starch (which leaves a hard centre and a sunken navel), cooks pre-cook a portion of the batter into a translucent paste, then fold the hot cooked slurry into the raw one before steaming. This seeds an even gel network so the cake sets smooth, springy and hole-free. The ratio runs around one part flour to two parts liquid, steamed hard for about 20 minutes; the bowl is oiled so the set disc releases. Red beans are pre-soaked and steamed soft, then scattered into the bowl or mixed through so they sit suspended rather than sinking into a lump.