Diced water chestnuts dyed ruby red and coated in tapioca flour, boiled until they turn into jewel-like beads with a crunchy core, then served in chilled, pandan-scented coconut milk over crushed ice. A glittering, textural Thai dessert.
Tub tim krob — 'crisp rubies' — are water chestnuts coated in red-tinted tapioca so they glint like pomegranate jewels, served in sweetened coconut milk over ice. The jewel-like look is half the joy of this beloved Thai dessert.
Each ruby gives a soft, slippery chew like boba before your teeth meet the crisp snap of water chestnut inside. The coconut milk is cool, lightly sweet and floral with pandan, the crushed ice making it a refreshing antidote to the heat.
Tapioca flour gelatinizes into a translucent, chewy shell when boiled, encasing the water chestnut so it keeps its signature crunch; an ice bath sets the coating firm and prevents the pieces from sticking together.
Variations
With jackfruit or palm seeds added, jasmine-scented syrup, mixed colored rubies, served with a scoop of coconut ice cream
On the Palate
Where Tub Tim Krob sits in the Thai flavor cloud
Ingredients
Serves 4
How it's made
8 steps · 40 min
- 110 min
Dice peeled water chestnuts into small, even cubes.
- 25 min
Toss the cubes in red food coloring or syrup until evenly stained.
- 38 min
Coat them thoroughly in tapioca flour, shaking off excess.
Watch outCoat each cube in a dry, even shell of tapioca and shake off the loose flour, or the excess turns gummy in the water.
- 45 min
Boil the coated cubes until they float and the coating turns clear.
Watch outThey're done the moment they float and the white coating turns glassy and clear — pull them before the crunch cooks out.
- 53 min
Scoop into iced water to set the chewy coating and stop cooking.
Watch outDrop them straight into ice water — the cold snaps the coating firm and springy and keeps the rubies from clumping.
- 610 min
Simmer coconut milk with sugar, salt and pandan leaf, then cool.
- 71 min
Spoon the rubies into bowls and pour over the coconut milk.
- 81 min
Add crushed ice and serve cold.
