Black Tapioca Pearls

Method

1. Use tapioca starch labelled as starch, not whole cassava flour, cornflour or potato starch. Weigh 100 g and reserve 10 g of it for a starter paste, leaving 90 g for the main dough. Keep the separate dusting starch aside. Dark sugar gives brown pearls; true black colour requires optional food colouring.
2. In a small nonstick saucepan dissolve dough sugar in the measured 65 ml water. Add optional colouring and bring to a full boil. Quickly whisk in the reserved 10 g starch and stir over low heat for 20–30 seconds until a thick translucent paste forms. This cooked starter binds the rest of the starch.
3. Turn off the heat and immediately stir in the remaining 90 g starch. Tip onto a heatproof surface and, once cool enough to handle safely, knead for 2–3 minutes into a smooth pliable dough. If crumbly, knead in boiling water by half-teaspoons; if sticky, add dusting starch sparingly. Do not pour in a large cold-water correction.
4. Keep most dough covered while working on a small piece. Roll into ropes about 8 mm thick, cut into short equal pieces and round into balls roughly 7–8 mm across. Toss lightly in dusting starch to prevent sticking. Work steadily because uncovered dough dries quickly; the small homemade pearls need not be perfectly identical.
5. Bring the 1.5 litres cooking water to a vigorous boil and shake excess dusting starch from the pearls. Add them gradually, stir gently for the first minute and simmer for 20–30 minutes. They should be translucent and pleasantly chewy without a hard floury centre; cut and cool one to test, extending cooking if needed.
6. Turn off the heat and rest the pearls in the covered hot water for 10 minutes. Meanwhile dissolve finishing sugar in the separate 40 ml water and simmer for 2 minutes to form a light syrup. Drain pearls, rinse briefly with potable warm water and coat in this syrup.
7. Use freshly cooked pearls the same day for best texture. Keep cooked pearls no longer than 2 hours at room temperature, or 1 hour above 32°C; refrigerate sooner if not serving. Refrigerated pearls firm up and need reheating in boiling water before use. Uncooked excess pearls can be frozen promptly on a tray rather than left drying on the counter for days.
8. Serve modest amounts in a drink prepared separately, or with a spoon. These chewy balls can be a choking hazard, especially through a wide straw; they are not suitable for very young children or anyone with swallowing difficulty. Do not eat raw starch dough.