Red Rubies Dessert (Tub Tim Krob)

Red Rubies dessert, or Tub Tim Krob, is a beautiful Thai dessert consisting of tapioca-coated red water chestnuts in chilled coconut milk. It’s a refreshing dessert that’s perfect for summertime!

The red rubbies have a chewy tapioca coating, similar to boba, and a crunchy center made from water chestnuts. The sweet coconut milk and ice combine to create a refreshing dessert.

Growing up, I loved eating Tub Tim Grob and Ruam Mit, especially during the hot summer months in Texas. I always asked my mom for extra crushed ice.

Ingredients Needed

There are just a few ingredients you’ll need to make this dessert, and most of them can be found at an Asian market; however, I’ve also linked them on Amazon.

• Coconut Cream Powder– I prefer using this powder over canned coconut cream because it has a smoother texture. You can adjust the consistency by adding more or less water.
• Sugar- Regular white sugar is fine. This will add sweetness to the coconut cream. You’ll want the cream to be on the sweeter side since the ice will dilute the taste when serving.
• Water Chestnuts– Use canned whole water chestnuts and slice them into bite-sized pieces. I’ve seen some people use Jicama as an alternative, but after testing it, I wasn’t a fan.
• Red Food Coloring– I used a natural food coloring, which has a deeper hue. You can use regular food coloring if you like.
• Tapioca Starch– I’ve only tested this recipe with the Asian brand of tapioca starch. However, this is essential for creating the chewy outside coating.

Making the coconut milk

In a large bowl, add the coconut powder, water, sugar, and salt. Use a whisk and mix until there’s no more powder. Taste for sweetness, keep in mind you want it to be sweeter since the dessert is served with crushed ice. Also, add a few ice cubes to the coconut milk once its done to keep it chilled.

Making the Red Rubies

Bring a pot of water to a boil, large enough to fit all the water chestnuts. Use whole canned water chestnuts, drain them, and slice each one into bite-size pieces.

Now add a few drops of red food coloring or more if you are using a natural food dye. Ensure each water chestnut piece is coated in dye.

In a large bag, add ¼ cup of tapioca starch, then add the red water chestnuts. If there is any liquid, drain the water chestnuts before adding them to the bag. Then add the remaining tapioca starch to the bag.

Twist the bag tightly at the top, ensuring some air remains in the bag. Shake the bag vigorously to ensure each water chestnut piece gets evenly coated. Empty the bag into a strainer to sift out any excess flour. Now add the water chestnuts to the pot of boiling water.

Once the red rubies float to the top, they are done. Use a skimmer and place it into a bowl of cold water. After a minute, drain the water and rinse them with cool water, then return them to the bowl filled with cool water. Repeat these steps one more time.

After the final rinse with cool water, add the water chestnuts to the bowl of coconut milk.

To serve, add some crushed ice to a bowl and ladle the coconut milk and red rubies on top. This dessert is best served on the day it is made. You can make it a few hours ahead of time and allow it to chill in the refrigerator.

The tapioca coating will expand the longer it sits in the milk, and it will start to become soggy instead of chewy. Therefore, I don’t recommend keeping leftovers for more than a day.

More Thai Desserts