Small balls of glutinous rice flour dough — plain white or coloured with pandan (green), roselle (red), or butterfly pea flower (purple) — simmered in sweetened, salted coconut cream until just cooked through. The balls set from the outer surface as they cook in the warm cream — a thin, set skin enclosing a soft, yielding interior. Bua loy is the Thai equivalent of the Japanese mochi-in-soup preparation — different ingredient vocabulary, same principle of a glutinous rice flour preparation served in a sweet cream. It is one of the most widely consumed Thai desserts and one of the simplest to make correctly.
**The dough:** - Glutinous rice flour: 200g. - Warm water: added gradually until the dough reaches the texture of soft earlobe — slightly sticky, easily shaped, smooth throughout. - No leavening, no fat. Pure starch-and-water dough. - Divide and colour individual portions with pandan juice (green), butterfly pea flower water (purple), or roselle infusion (pink-red) — the colourings are all natural infusions and contribute minor aromatic notes. - Roll into balls approximately 2–2.5cm diameter. **The coconut cream:** - Sweetened with palm sugar, salted with a definite pinch of salt. - Heated to a gentle simmer. - The cream should not boil vigorously — the balls are fragile and vigorous boiling breaks them. **The cooking:** 1. Lower the balls into the gently simmering coconut cream. 2. They initially sink to the bottom (the uncooked dough is slightly denser than the cream). 3. Within 3–4 minutes: the balls have cooked through and the outside has set. They rise to the surface — this is the visual doneness indicator. 4. 1 minute after floating: the balls are done. Remove from heat. Decisive moment: The floating of the cooked balls. Glutinous rice starch gelatinises fully during cooking and becomes slightly less dense than the surrounding liquid — the finished balls float. This is reliable and universal for all glutinous rice flour preparations cooked in liquid (the same test applies for Japanese dango, Korean chapssaltteok in hot water, and Chinese tang yuan). Sensory tests: **Feel — the dough before cooking:** The correctly hydrated glutinous rice flour dough should feel like the flesh of the earlobe when pinched — soft, slightly elastic, yielding without tearing. Too stiff: the balls crack on the surface during cooking. Too soft: the balls dissolve into the cream. **Texture — eating:** The ball exterior: a thin, set, slightly translucent skin — glutinous rice flour's fully gelatinised outer layer. The interior: soft, yielding, slightly sticky, with a clean, mild flavour. The contrast between the set outer skin and the softer interior is present but subtle.
David Thompson, *Thai Food* (2002); *Thai Street Food* (2010)