Khao Tom Mud — banana and sticky rice tied in banana leaf

i. Origin & history

Wrapping rice in leaves for cooking and carrying is one of the oldest food techniques in mainland Southeast Asia, and khao tom mud is the Thai form of a regional tradition. Khao means rice, tom means boiled, and mat (often spelled mud in English) means tied — describing the leaf parcels bound with strips of bamboo or string. Similar sweets are made in Laos (khao tom), Cambodia (num ansom chek) and Vietnam (bánh tét chuối).

Khao tom mud has a strong place in Thai Buddhist life. It is prepared in large quantities for Ok Phansa, the end of the three-month Buddhist Lent in October, and the Tak Bat Devo merit-making ceremony that follows, when people give food to monks. The parcels are easy to carry, keep for a day or two without refrigeration and can be eaten without utensils — practical qualities for an offering. It is also made for Songkran, weddings and other ceremonies.

The parcels are traditionally tied together in pairs. The practical reason is that pairs are easier to hang, carry and give; the symbolic one, often mentioned, is that the joined pair stands for togetherness, which makes khao tom mud a fitting gift at weddings.

The banana is usually kluai nam wa, a short, plump, starchy Thai banana that becomes soft, sweet and slightly pink when cooked. Black beans (thua dam) are often mixed into the rice for colour and earthiness, and some versions use taro, pumpkin or sweet potato. The rice may be white or tinted blue with butterfly pea flowers.

ii. Why the rice is part-cooked in coconut milk

Khao tom mud uses a two-stage method. First, soaked glutinous rice is stirred in hot coconut milk with sugar and salt over low heat until it absorbs all the liquid and becomes thick and sticky but is still firm in the centre. This seasons every grain, coats it in coconut fat and makes it sticky enough to wrap. Then the wrapped parcels are steamed for an hour to finish cooking the rice and banana together.

Stopping the first stage at the right point is crucial. If the rice is cooked through in the pan, it turns mushy and pasty after steaming. If the liquid has not been fully absorbed, the rice is too wet to shape and leaks from the leaves.

Glutinous rice is essential: its starch is almost all amylopectin, which makes the grains stick together into a solid, chewy parcel. Soaking it for at least four hours makes sure the grains cook evenly.

The banana leaf is more than a wrapper. It keeps the parcels moist, prevents them sticking and releases a subtle, tea-like, grassy aroma during steaming that is part of the dish's flavour. Softening the leaves over a flame or in hot water first makes them pliable so they fold without splitting.

iii. Ingredients

Makes 10 servings · scroll the side panel to adjust

• 400 g Thai glutinous rice
• 50 g dried black beans (optional)
• 500 ml coconut milk
• 100 g sugar
• 1 tsp salt
• 2 pandan leaves, knotted
• 5 ripe kluai nam wa or small bananas, peeled and halved lengthwise
• 10 pieces banana leaf, about 25 × 20 cm, plus strips for tying

Glutinous rice (sticky rice) is essential. Kluai nam wa bananas are sold in Thai and Asian shops; small ripe dessert bananas, or plantains cut into chunks, work as substitutes. Black beans must be soaked overnight and boiled until tender before using; canned black beans, rinsed, work too. Banana leaves are sold frozen; thaw, wipe and soften over a flame. Kitchen string can replace banana-leaf ties.

iv. Method

1. Rinse the rice until the water runs nearly clear and soak for at least 4 hours, or overnight. If using black beans, soak them overnight separately, then simmer for 30–40 minutes until just tender. Drain both.
2. In a wide pan, heat the coconut milk with the sugar, salt and pandan until the sugar dissolves. Add the drained rice and stir over low heat for 10–15 minutes, until all the liquid is absorbed and the rice is thick and sticky but still firm in the centre. Stir in the beans and remove the pandan. Cool slightly.
3. Soften the banana leaves over a flame or in hot water until glossy and pliable. Wipe dry.
4. Lay a leaf shiny side up. Spread 2 tablespoons of rice in a rectangle in the centre, lay a banana half on top, and cover with another 2 tablespoons of rice, pressing it round the banana.
5. Fold the long sides of the leaf over the rice, then fold the ends under to make a neat rectangular parcel. Repeat with the rest.
6. Place two parcels together, folded sides facing, and tie them firmly with banana-leaf strips or string.
7. Steam over boiling water for 50–60 minutes, topping up the water as needed, until the rice is translucent and soft and the banana is tender.
8. Cool slightly before unwrapping. Serve warm or at room temperature.

v. Tips & common mistakes

• Soak the rice well. Unsoaked rice stays hard in the centre after steaming.
• Do not fully cook the rice in the pan. It finishes in the steamer; overcooking makes it pasty.
• Stir constantly over low heat. Coconut milk and sticky rice scorch easily.
• Use ripe bananas. Underripe bananas stay starchy and astringent; ripe ones turn soft and sweet.
• Wrap and tie firmly. Loose parcels let steam in unevenly and can come apart.
• Season the coconut milk with salt. The salty-sweet balance is essential to Thai sweets.

vi. Variations

Khao tom mud sai thua dam mixes black beans into the rice; blue khao tom mud uses butterfly pea flowers to colour the rice. Fillings may include taro, pumpkin or sweet potato. A savoury version, khao tom mud sai mu, fills the rice with seasoned pork and mung beans.

For other Thai sticky rice desserts, see coconut rice cake and sticky rice with durian. Across Asia, compare Filipino suman, Chinese sticky rice dumplings and Vietnamese bánh chuối.

vii. Serving & storage

Khao tom mud is served warm or at room temperature, unwrapped at the table, as a snack or dessert. It is eaten by hand and goes well with hot tea or coffee. Some people sprinkle it with grated coconut or a little sugar.

The parcels keep for a day at room temperature and up to 3 days in the fridge, still wrapped. Re-steam for 10–15 minutes to soften the rice before serving. They freeze well for up to a month; steam from frozen for 20–25 minutes.

ix. More from Thai

• Coconut Rice Cake — Thai coconut sticky rice
• Sticky Rice with Durian — coconut rice and durian
• Sankaya — pumpkin custard
• Khanom Chan — nine-layer cake
• Suman — Filipino rice in banana leaf
• Sticky Rice Dumplings — Chinese zongzi