For cookbook author and writer Leela Punyaratabandhu, the scent of mangos still has the power to transport her back to springtime at her great-grandparents’ home in Bangkok. There, as the days grew warmer and longer, she and her family plucked the fruits from their garden’s trees, collected them in baskets, and organized them on their kitchen shelves. As the fruits grew softer and sweeter, their musky, floral perfume permeated the entire house. “It’s one of the olfactory memories from my childhood that I associate with warmth, happiness, and abundance,” Punyaratabandhu wrote in an email.
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Once a fruit had reached peak saccharine softness, it was time to make Thailand’s most famous dessert: khao niaow ma muang. Consisting of thick, golden slices of mango; subtly sweet, coconut-flavored sticky rice; a salty coconut sauce; and crunchy toasted mung beans, this dish is a delicate balancing act of flavors and textures. With a perfectly ripe mango, it’s downright harmonious, so from late March through early May, mango lovers flock to street stalls and restaurants across Thailand to take full advantage of the in-season fruit. “Whenever mango season arrives, it’s a must-have,” said Pailin Chongchitnant, blogger, YouTuber, and author of the cookbooks Hot Thai Kitchen (2016) and Sabai (2023).
Thai Mangos are Versatile
The 200-plus varieties of mangos grown in Thailand are essential to the country’s cuisine. Supremely versatile, mangos are eaten raw and cooked and used in both savory and sweet applications. Green, crunchy, and tart fruits are commonly served sliced with a sprinkle of salt, chili flakes, and sugar as a snack; shredded into a salad; or alongside the sweetened fish sauce dip nam pla waan. Others, such as the two favorites for khao niaow ma muang, Nam Dok Mai and Ok Rong, are only consumed fully ripe, boasting a candylike sweetness; velvety flesh; and distinct, floral musk.
The Waiting Game
Khao niaow ma muang comes together quickly in the kitchen from a short ingredient list, but some planning ahead is still necessary. Mangos in the United States are sold underripe, and the fruits must be given a few days to turn sweet and soft before you begin the recipe, or you risk disrupting the iconic dessert’s signature fusion of flavors. “The quality of the mango is everything,” Chongchitnant said. Punyaratabandhu concurred. “A perfect batch of sticky rice paired with a bad mango would be a big failure,” she said.
So, I bought a handful of Ataulfos, a Mexican variety available in the United States that comes close to replicating the Thai varieties best loved for this dish, and waited. Once they were soft and slightly wrinkly, it was time to cook.
Science: Sticky Starch
What gives sticky rice its signature cohesion? It’s all about amylopectin. Amylopectin and amylose are the two types of molecules that make up starch, and different varieties of rice contain different amounts and ratios of each molecule. When rice is cooked, its starch granules break apart and release amylose and amylopectin onto the surfaces of the grains of rice. Sticky rice contains high amounts of amylopectin, a bushy-shaped molecule with many branches. This shape makes the molecules stick to each other like Velcro. Rice varieties such as basmati and jasmine, on the other hand, contain more amylose, which is a straight chain rather than a sticky branching molecule. This makes these varieties cook up as distinct grains.
Full Steam Ahead
Shiny, glutinous, coconut-flavored grains of sticky rice form the foundation of khao niaow ma muang. I washed the pearly grains to remove their excess surface starch and then soaked them in cold water. Sticky rice is steamed (rather than cooked via absorption or boiling, which would break the delicate grains apart and render them mushy), so the grains must be adequately hydrated beforehand. This soaking period, while critical, can be brief: I found that rice soaked for just 1 hour took up nearly the same amount of water as batches soaked for 24 hours.
Traditionally, the rice is then covered and steamed in a cone-shaped bamboo vessel placed atop a metal pot of boiling water. This piece of equipment has drawbacks (the basket is quite large) and, according to Chongchitnant, even most commercial rice vendors use other steamer setups. I liked a bamboo steamer: I nestled the rice in a damp kitchen towel (to keep the cooked rice from sticking) and then flattened it in the steamer so that the rice would cook evenly. I set the steamer over a wok filled with 4 cups of water that I’d brought to boil, just enough to submerge the very bottom of the vessel, and then I adjusted the heat to gently steam the rice until it was tender and translucent but still had its characteristic chew, about 20 minutes.
Do the Ripe Thing
Ataulfo (also known by the name “Honey” or “Champagne”) mangos may need a few days to ripen on the countertop to reach peak sweetness. They are ready when they yield to gentle pressure and their skins start to wrinkle and spot.
As the rice cooked, I prepared a soak of rich, full‑fat coconut milk; sugar; and salt, heating the mixture on the stove until the sugar dissolved. This soak would subtly sweeten the rice, tipping it just into dessert territory without overpowering the mango. I poured the warm liquid over the top of the cooked sticky rice, and while the grains were swimming in the liquid at first, they absorbed it all after 15 minutes, becoming plump and glossy.
One Can, Sugared and Salted
Creamy, full-fat coconut milk transforms into two distinct components of khao niaow ma muang: a soak for the rice and a finishing sauce. For the soak, the coconut milk is sweetened with sugar and then poured warm over the top of the cooked sticky rice. The coconut sauce that is spooned over the top of the rice, in contrast, is salted, and brings a hint of savory to the finished dish.
A Study in Contrasts
On to the garnishes. A salty coconut sauce brings a savory edge to the sweet fruit and rice; I made one from the rest of my can of coconut milk, salt, and cornstarch. And toasted mung beans (see our recipe on page 29) contribute textural variety to the dessert’s plush profile, providing pops of crunchiness without adding any distracting flavor.
I eagerly assembled my dessert, mounding the rice onto plates and then arranging thick, golden slices of mango alongside. After drizzling with the coconut sauce and sprinkling with toasted mung beans, I took a bite. At once fresh, sweet, juicy, soft, smooth, creamy, chewy, and crunchy, the khao niaow ma muang was a jolt to my system, a rush of welcome warmth and brightness.