Crystal Glutinous Rice Balls With Purple Sweet Potato Filling

I used the Teochew-style crystal skin method to make this chewy crystal glutinous rice balls. These crystal rice balls with purple sweet potato filling are not only pleasing to the eye, they are delicious too.

Ingredients:
100g purple sweet potato       
20g milk
200g tapioca flour
20g white sugar
boiling water

Method:
1) Peeled and steamed the purple sweet potato, then mashed into a puree.

2) Add the milk, knead well and divide into 10g purple sweet potato filling.

3) Mix tapioca flour and white sugar, add hot water while mixing with chopsticks. Be sure to use hot boiling water so the skin will be chewy.

4) Finally, use your hands to knead into a soft, non-sticky, smooth dough. Cover the dough for 20 minutes to keep it moist as tapioca dough is easy to dry out. If the dough becomes dry, add a little hot water and knead again.

5) Take 10g of dough (cover the rest of the dough to keep it moist) and roll as thin as possible, and put a purple sweet potato ball in the center.

6) Wrap the filling into a ball. Be careful not to trap air inside.

7) Cover the glutinous rice balls to prevent drying and cracking. Keep frozen when you can't finish cooking.

8) Put boiling water in the pot, put in the glutinous rice balls. Cook until the balls float. Close the lid for 4 minutes, and the skin will change from opaque to transparent. The last step is important, remember to keep the lid closed for a while to allow the skin to become transparent.

9) Boil water, add in white/brown sugar and pandan leaves. Put in the purple sweet potato crystal glutinous rice balls. Serve hot or cold.