Tapioca Pearls from Scratch

Before you start

Homemade boba is a scalded dough. Boiling water poured onto part of the tapioca starch gelatinizes it into a sticky paste, and that paste binds the remaining dry starch into a dough you can roll. Raw tapioca starch with cold water will never come together, so the temperature of that first addition is the whole trick.

After that it is about consistency and timing. Roll pearls to an even 8 to 10 mm, dust them well so they do not stick, then boil them until no white dot remains in the center. Cooked pearls are at their best soon after cooking and turn hard in the refrigerator, so cook only what you will serve.

Ingredients

• Dough40 g (3 tbsp packed) dark brown sugar or muscovado
• 70 ml (scant 5 tbsp) water
• 120 g (1 cup) tapioca starch — also sold as tapioca flour; plus extra for dusting
• Syrup60 g (1/3 cup packed) dark brown sugar
• 60 ml (¼ cup) water
• Cooking2 liters (8 cups) water — for boiling the pearls

Method

1. Put the 40 g brown sugar and 70 ml water in a small saucepan and bring to a full rolling boil, stirring until the sugar dissolves.
2. Take the pan off the heat and immediately add about 30 g (1/4 cup) of the tapioca starch. Stir hard with the spatula; within seconds it turns into a glossy, sticky paste. If it stays thin and milky, the water was not hot enough, so return the pan to low heat and stir until it thickens.
3. Add the remaining starch to the pan and stir until it forms a shaggy mass. Tip it onto a work surface dusted with starch.
4. Knead while the dough is still warm, about 2 to 3 minutes, until it is smooth and feels like soft play dough. If it cracks, wet your hands and knead again; if it is sticky, dust with a little more starch.
5. Divide the dough into 4 pieces. Keep the pieces you are not using covered with a bowl so they do not dry out.
6. Roll one piece into a rope about 8 mm (1/3 inch) thick, cut it into 8 mm pieces and roll each between your palms into a ball. Toss the pearls in starch on a baking sheet. Repeat with the rest.
7. Bring the 2 liters of water to a vigorous boil. Shake excess starch off the pearls in a strainer and drop them in, stirring at once so they do not stick to the bottom.
8. When the pearls float, lower the heat to a steady simmer, cover partly and cook for 20 minutes, stirring occasionally. Turn off the heat, cover fully and rest for 10 to 15 minutes.
9. Cut one pearl in half. It is done when it is translucent all the way through with no opaque white dot. Drain the pearls and rinse them briefly in cool water to stop them sticking.
10. Simmer the 60 g brown sugar and 60 ml water for 2 minutes until slightly thick, add the pearls and stir to coat. Use them in drinks while they are still warm or at room temperature.

Tips for success

• Pearls swell by roughly half as they cook, so a raw 8 mm pearl becomes a standard boba size that fits through a wide boba straw.
• Freeze extra uncooked pearls on a starch-dusted tray, then bag them. Cook them straight from frozen, adding 3 to 5 minutes to the simmer.
• Use plenty of boiling water. A crowded pot drops below a boil and the pearls stick together and turn gummy.

Substitutions

Dark brown sugar in the dough

Plain white sugar works and gives pale pearls with a milder flavor. A teaspoon of cocoa powder or black cocoa darkens them if you want the classic black color.

Brown sugar syrup

Honey thinned with an equal amount of hot water coats the pearls nicely and suits green and jasmine teas.

Tapioca starch

There is no good substitute. Cornstarch or potato starch will not give the bouncy chew and fall apart when boiled.

Variations

Matcha pearls

Replace 1 teaspoon of the starch with sifted matcha and use white sugar in the dough for green pearls.

Mini pearls

Roll the dough into 4 to 5 mm balls and cut the simmer to about 10 minutes, followed by a 10-minute rest.

Troubleshooting

The dough crumbles and will not hold together

The starter paste was not gelatinized because the water cooled before the starch went in. Add a tablespoon of boiling water at a time and knead until smooth.

The pearls dissolved into a cloudy mess in the pot

The water was not boiling when they went in, or they were not stirred. Always add pearls to a hard boil and stir for the first 30 seconds.

The centers are still white and hard

Simmer for 5 more minutes and rest them covered again. Larger pearls need more time, so roll them smaller next batch.

Storage

Cooked pearls are meant for the same day; serve them within about 2 hours and do not leave them out longer, since the texture fades and they are a moist, sugary food. Refrigerated pearls turn hard and chalky. Uncooked pearls keep frozen in a sealed bag for about 1 month.