Kue Putu — pandan rice cakes steamed in bamboo tubes

i. Origin & history

Kue putu belongs to the broad family of Indonesian kue, the snacks and sweets bought from markets and street vendors, and it is especially tied to Java, where it has been sold for generations. The vendor pushes a cart or carries a pole with a small charcoal or gas steamer on which the bamboo tubes stand upright over vents; steam escaping through a narrow pipe produces the whistle that announces the seller through residential streets, usually in the evening.

The name is generally connected with puttu, the steamed rice-flour and coconut dish of South India and Sri Lanka, which is also steamed in cylinders. The similarity of name, method and ingredients has led many food historians to suggest that the technique travelled with the long trade between southern India and the Indonesian archipelago, though the Indonesian version, with its palm-sugar centre and pandan colour, has long been entirely its own.

Across the Malay world the same idea appears with local variations. In Malaysia the bamboo version is called putu bambu. In Singapore and parts of Malaysia, putu piring is made in shallow round moulds covered with cloth, giving a flat, disc-shaped cake with the same gula Melaka filling. Putu mayam, despite the shared word, is a different dish — fine rice-flour noodles pressed into nests, of Tamil origin, eaten with coconut and sugar.

Kue putu often shares a cart with klepon, its closest relative in flavour: both combine pandan rice dough, molten palm sugar and grated coconut, but klepon is a boiled glutinous-rice ball while putu is a steamed, crumbly cake.

ii. Why the flour is damp, not a batter

Unlike most steamed cakes, kue putu is not made from a batter. The rice flour is moistened only until it looks like damp sand and clumps when squeezed, then rubbed through a sieve to make it fine and even. It is this loose, crumbly mixture that goes into the tube, so the steam can pass through it.

In the steamer, each grain of moistened flour gelatinises at its surface and bonds lightly to its neighbours, without the starch ever forming a continuous dense mass. The result is a tender, slightly crumbly cake that holds together when pushed out but falls apart pleasingly in the mouth. Too much water and the flour turns into a solid, sticky paste that steams into a rubbery plug; too little and it does not bind at all.

The palm sugar sits in the middle as a separate pocket. As the cake steams, the sugar melts into a syrup that is held in place by the surrounding flour — which is why the flour must be packed lightly but evenly, with no channels for the syrup to escape. When the cake is bitten, the hot syrup runs out.

Traditional vendors use rice flour made from soaked, pounded rice, which is slightly damp and coarser than dry supermarket flour. Many home cooks imitate it by briefly steaming or toasting dry rice flour before moistening, which gives a better texture than raw flour. Bamboo tubes add a faint woody aroma, but small metal or silicone moulds work well at home.

iii. Ingredients

Makes 12 servings · scroll the side panel to adjust

• 250 g rice flour (not glutinous)
• 8 pandan leaves, cut up
• 150 ml water
• ½ tsp salt
• 120 g palm sugar (gula Jawa or gula Melaka), finely chopped
• 150 g fresh or frozen grated coconut
• ¼ tsp salt, for the coconut

Use plain rice flour, not glutinous rice flour, which would steam into a sticky, chewy mass. Asian grocers' rice flour is finer and more consistent than most health-food-shop versions. Pandan gives both colour and scent; if you have only pandan paste, use ½ tsp in plain water. The traditional palm sugar is gula Jawa (Javanese coconut or arenga palm sugar); gula Melaka or Thai palm sugar are equivalent. It must be finely chopped or grated so it melts fully in 10 minutes. Fresh grated coconut, steamed briefly with salt, is essential — desiccated coconut is too dry and sweet; if you must use it, moisten it with a little warm water first.

iv. Method

1. Spread the rice flour in a heatproof dish and steam it for 10 minutes, or toast it in a dry pan over low heat for 5 minutes without colouring. Cool completely and break up any lumps.
2. Blend the pandan leaves with the water and squeeze through a fine sieve or cloth to get about 120 ml of green juice. Stir in the ½ tsp salt.
3. Sprinkle the pandan juice over the flour a little at a time, rubbing it in with your fingertips, until it looks like damp sand and holds together when squeezed but crumbles when poked. You may not need all the juice. Push the mixture through a coarse sieve to make it fine and even.
4. Mix the grated coconut with the ¼ tsp salt and steam it for 5 minutes. Keep warm.
5. Bring a steamer to a full boil. Lightly fill each bamboo tube or small mould one-third full with the flour mixture, add 1 tsp palm sugar in the centre, then fill to the top with more flour and level it without pressing.
6. Steam the filled moulds for 8–10 minutes over high heat, until the colour has deepened and the top looks set and slightly translucent. Work in batches.
7. Push each cake out with a chopstick or the back of a teaspoon onto a piece of banana leaf. Top or roll in the warm coconut and serve immediately.

v. Tips & common mistakes

• Add the water slowly. The line between damp sand and paste is narrow; the mixture should never look wet. If it does, rub in a spoonful of extra flour.
• Always sieve the moistened flour. Lumps steam into hard nuggets. Sieving also aerates the mixture so the cake is light.
• Fill loosely and level, never pack. Pressed flour steams into a dense plug that the steam cannot penetrate evenly.
• Keep the sugar in the centre. Sugar touching the side of the mould leaks out and caramelises onto it, leaving a hollow cake.
• Steam on a fierce heat. The steam must pass up through the flour quickly; on a gentle heat the cakes turn soggy.
• Serve straight from the steamer. As kue putu cools, the sugar sets and the crumb dries — they are made to be eaten within minutes.

vi. Variations

Putu bambu in Malaysia is essentially the same cake. Putu piring from Singapore and Johor is steamed in shallow round moulds and served on a square of pandan leaf. Kue putu mangkok is a related Indonesian steamed cake made in small bowls, often coloured and with a coconut-sugar filling. Modern carts sell cocoa and other flavoured versions, and some fill the centre with cheese or chocolate.

The combination of pandan, palm sugar and coconut runs through many Indonesian and Malaysian sweets: klepon and onde-onde are filled rice balls, dadar gulung rolls palm-sugar coconut inside a pandan crêpe, and kue lapis is a steamed layered cake. The South Indian puttu is the steamed rice-flour cousin, usually eaten for breakfast.

vii. Serving & storage

Kue putu is an evening snack, sold hot and eaten from a piece of banana leaf or paper, often several at a time. Serve it straight from the steamer, in small batches, with tea or coffee.

It does not keep well. The flour mixture can be prepared a few hours ahead and kept covered so it does not dry out, and the coconut can be steamed in advance and kept chilled for a day. Cooked kue putu turns hard and dry as it cools; if you have leftovers, re-steam them for 3–4 minutes to soften the crumb and remelt the sugar, and eat them that day.

ix. More from Indonesian & Malaysian

• Klepon — pandan palm-sugar balls
• Kue Lapis — layered steamed rice cake
• Dadar Gulung — pandan crêpes with coconut
• Kue Apem — steamed rice-flour cakes
• Onde-Onde — sesame balls
• Puto — Filipino steamed rice cakes