I recently tried my hand at making a Thai dessert called Tub Tim Grob, and I was surprised by how harmonious the crunch of the ruby pearls was when paired with the sweet, creamy coconut milk. Preparing it was a delightful process, from the fun of turning water chestnuts into vibrant gems to the gratifying taste of the dish’s complex layers of flavor and texture.

I really enjoy making a light and cheerful dessert such as Tub Tim Grob. This dish presents a delightful contrast in texture, featuring the crunchy cubes of water chestnut coated in tapioca flour, with the decadent richness of coconut milk.
It is a dessert that is way too easy to consume, as you feel you’re indulging in something so silky and luscious, yet not heavy at all. Its bright and vibrant color—thanks to a drop of red food coloring—makes it visually interesting, as well.
Tub Tim Grob Recipe Ingredients

- Water Chestnuts: Low in calories, rich in fiber, adds a crunchy texture.
- Tapioca Flour: Provides starchiness, creates a chewy coating, gluten-free.
- Coconut Milk: Creamy base, rich in healthy fats, adds a subtle sweetness.
- Granulated Sugar: Sweetens the dessert, enhances flavors, energy source.
- Pandan Leaves (Optional): Adds a fragrant aroma, subtle vanilla flavor, natural scent.
Tub Tim Grob Recipe Ingredient Quantities
- 1 cup water chestnuts, peeled and diced
- 1 cup tapioca flour
- 1 cup coconut milk
- 1/4 cup granulated sugar
- 1/4 teaspoon salt
- 1-2 drops red food coloring
- 1-2 cups crushed ice
- Water for boiling
- Pandan leaves (optional, for infusion)
How to Make this Tub Tim Grob Recipe
1. Mix the diced water chestnuts with red food coloring in a bowl, using anywhere from 1-2 drops per batch.
2. Put the tapioca flour in a bowl apart from the others. Roll each piece of the colored water chestnut in the tapioca flour; make sure each piece is well-coated and shake off any excess flour.
3. In a saucepan, bring water to a boil. Carefully lower the coated water chestnuts into the boiling water. Stir to keep them from clumping together. Allow to boil until they have all risen to the top, about 2-3 minutes.
4. After they float, take a slotted spoon to extract the water chestnuts and swiftly move them to a bowl of ice-cold water. Allow them to sit for roughly 5-10 minutes to set the coating.
5. Set aside the water chestnuts after draining them.
6. In another saucepan, mix the coconut milk, sugar, and salt. If you are using pandan leaves, add them now. Heat the mixture over medium heat, stirring almost continuously until the mixture is uniform and the sugar has dissolved completely. See that it does not come to a boil. If you used pandan leaves, remove them before serving.
7. Get the bowls ready for serving by putting crushed ice in them.
8. Place the dry-fried water chestnuts, also known as “ruby pearls”, in each bowl. Spoon the savory sauce over the water chestnuts in each bowl.
9. Sweetened coconut milk is poured over the ice and ruby pearls.
10. Serve directly after preparing for a dessert that will refresh. The main elements of the crunch come from the water chestnuts that offset the sweet and cool elements of the coconut milk.
Tub Tim Grob Recipe Equipment Needed
1. Mixing bowls (2)
2. Measuring cups and spoons
3. Saucepan (2)
4. Slotted spoon
5. Stirring spoon
6. Ice water bath (large bowl)
7. Serving bowls
8. Cutting board
9. Chef’s knife
FAQ
- What is Tub Tim Grob?Tim Grob is a well-liked dessert in Thailand. It consists of crunchy, water chestnut “rubies” that are coated in tapioca flour and served in sweetened coconut milk with crushed ice. The heat and humidity of Thailand make this dessert a particularly refreshing one to consume.
- Can I use something other than red food coloring?Certainly! You have the option of using natural substitutes, like beet juice or hibiscus powder, to tint the water chestnuts.
- What does the pandan leaf do?Pandan leaves are not required but offer a fragrant, aromatic flavor to the coconut milk, which lifts the overall taste of the dessert.
- Why is tapioca flour used in this recipe?The water chestnuts are coated with tapioca flour, resulting in a chewy, jelly-like texture when cooked.
- How long can I store Tub Tim Grob?You can store the coated water chestnuts in the refrigerator for up to two days. This makes it easier to serve your guests just before the eatery’s curtain goes up. But they are so much better fresh! Enjoy!
- Can I substitute another type of milk for coconut milk?The dessert gets its signature essence from coconut milk, yet you can substitute other plant-based milks with success. The flavor profile, however, will not be the same.
Tub Tim Grob Recipe Substitutions and Variations
For a similar crunch, water chestnuts can be substituted with jicama.
Substitute cornstarch or potato starch for tapioca flour.
Replacing coconut milk with almond milk makes for a different flavor profile.
Instead of using granulated sugar, you can use honey or agave syrup.
For a natural coloring alternative, beet juice can substitute red food coloring.
Pro Tips
1. Enhance Color and Flavor For an extra burst of color and slight hint of fragrance, consider using natural beet juice instead of red food coloring. This will give the water chestnuts a vibrant red hue and a subtle earthy sweetness.
2. Pandan Infusion When infusing the coconut milk with pandan leaves, lightly crush the leaves before adding them to release more of their aromatic oils. This will deepen the flavor of the coconut milk, adding an authentic Southeast Asian touch.
3. Tapioca Flour Coating To ensure a thicker, more even coating on the water chestnuts, double-coat them. After the first roll in tapioca flour, let them rest for a few minutes before rolling them again. This creates a thicker layer that remains chewy after cooking.
4. Ice Bath Timing Be precise with the timing in the ice bath; leaving the chestnuts in for exactly 5-10 minutes ensures the coating sets properly without becoming too hard. This step is crucial for the right texture contrast.
5. Chill Coconut Milk For an even more refreshing dessert, chill the coconut milk mixture before assembling the dish. This enhances the overall cooling effect and contrasts with the chewy texture of the “ruby pearls” and the crunchy ice.

Tub Tim Grob Recipe
My favorite Tub Tim Grob Recipe
Equipment Needed:
1. Mixing bowls (2)
2. Measuring cups and spoons
3. Saucepan (2)
4. Slotted spoon
5. Stirring spoon
6. Ice water bath (large bowl)
7. Serving bowls
8. Cutting board
9. Chef’s knife
Ingredients:
- 1 cup water chestnuts, peeled and diced
- 1 cup tapioca flour
- 1 cup coconut milk
- 1/4 cup granulated sugar
- 1/4 teaspoon salt
- 1-2 drops red food coloring
- 1-2 cups crushed ice
- Water for boiling
- Pandan leaves (optional, for infusion)
Instructions:
1. Mix the diced water chestnuts with red food coloring in a bowl, using anywhere from 1-2 drops per batch.
2. Put the tapioca flour in a bowl apart from the others. Roll each piece of the colored water chestnut in the tapioca flour; make sure each piece is well-coated and shake off any excess flour.
3. In a saucepan, bring water to a boil. Carefully lower the coated water chestnuts into the boiling water. Stir to keep them from clumping together. Allow to boil until they have all risen to the top, about 2-3 minutes.
4. After they float, take a slotted spoon to extract the water chestnuts and swiftly move them to a bowl of ice-cold water. Allow them to sit for roughly 5-10 minutes to set the coating.
5. Set aside the water chestnuts after draining them.
6. In another saucepan, mix the coconut milk, sugar, and salt. If you are using pandan leaves, add them now. Heat the mixture over medium heat, stirring almost continuously until the mixture is uniform and the sugar has dissolved completely. See that it does not come to a boil. If you used pandan leaves, remove them before serving.
7. Get the bowls ready for serving by putting crushed ice in them.
8. Place the dry-fried water chestnuts, also known as “ruby pearls”, in each bowl. Spoon the savory sauce over the water chestnuts in each bowl.
9. Sweetened coconut milk is poured over the ice and ruby pearls.
10. Serve directly after preparing for a dessert that will refresh. The main elements of the crunch come from the water chestnuts that offset the sweet and cool elements of the coconut milk.







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