Taro Cake — sweet steamed taro and coconut cake

i. Origin & history

Taro (Colocasia esculenta) is one of the oldest cultivated crops in Asia, a starchy corm grown throughout southern China, Taiwan and Southeast Asia. Chinese cooks use it in both savoury and sweet dishes, from braised pork with taro to the Teochew taro paste dessert orh nee and the taro balls of Taiwanese dessert shops.

The name 'taro cake' covers two very different things, which causes confusion. The best known is the Cantonese wu tau gou (芋頭糕), a savoury steamed cake of taro and rice flour studded with Chinese sausage, dried shrimp and mushrooms, sliced and pan-fried at dim sum and especially at Lunar New Year. Like turnip cake and nian gao, it is one of the New Year gao, because gāo (糕, cake) sounds like gāo (高, high or rising) — a wish for advancement in the coming year.

The sweet taro cake on this page belongs more to the coconut-milk kitchens of the south and of Southeast Asia: Hainanese, Teochew and Hokkien communities, and Malaysian, Singaporean and Nyonya cooks, for whom it is a kuih — a small steamed teatime or market sweet. In Malaysia it is often called kuih keladi (keladi being Malay for taro); Thai cooks make similar sweets with taro and coconut cream. These cakes use tapioca starch or rice flour rather than wheat, and are rolled or topped with grated coconut.

It sits alongside other steamed kuih, like Indonesian kue lapis and Malaysian seri muka, and with other taro sweets, from Filipino ube desserts to the steamed Hong Kong cakes of the dim sum trolley.

ii. Handling taro, and how the starches set

Raw taro contains calcium oxalate crystals, which irritate the skin and the mouth. That is why taro is never eaten raw and why many cooks wear gloves to peel it, or oil their hands; the itch is harmless but unpleasant. Thorough cooking breaks down the crystals completely, so the cooked cake is perfectly safe.

Taro is very starchy, and cooking it until tender before mashing is the key step. Steamed taro mashes into a smooth, dry, fluffy purée that blends easily into the batter. Undercooked taro stays waxy and lumpy and can keep a slightly scratchy feel. Large Chinese 'betel nut' taro, with its purple-flecked flesh, mashes best and gives the characteristic lilac speckles.

The binding comes from starch. Tapioca starch gelatinises during steaming into a clear, springy gel that gives the cake its slight chew, while rice flour makes it softer and more tender. Coconut milk adds fat, richness and moisture. Steamed rather than baked, the cake sets evenly without a crust and stays moist.

Like most starch-based kuih, taro cake firms as it cools and must be completely cool before cutting, or it will be gummy. But it also hardens in the fridge as the starches retrograde, so it is best kept at room temperature and eaten within a day or two, or briefly re-steamed if it firms up.

iii. Ingredients

Makes 12 servings · scroll the side panel to adjust

• 500 g taro, peeled weight
• 400 ml coconut milk
• 150 g sugar
• ½ tsp salt
• 2 pandan leaves, knotted (optional)
• 120 g tapioca starch
• 60 g rice flour
• 100 ml water
• 1 tbsp neutral oil, for the tin
• 100 g freshly grated or desiccated coconut, to coat

Look for large taro with firm, dry, purple-speckled flesh, sold in Chinese and Southeast Asian shops; small 'eddoe' taro work but are slimier. Full-fat coconut milk gives the richest cake. Tapioca starch (sold as tapioca flour) gives chew and rice flour tenderness — not glutinous rice flour, which would make the cake gluey. Fresh grated coconut mixed with a pinch of salt and steamed for 5 minutes is the traditional coating; desiccated coconut lightly toasted is a good substitute. The cake is naturally vegan and gluten-free.

iv. Method

1. Wearing gloves, peel the taro and cut it into 2 cm cubes. Steam over boiling water for 20–25 minutes until a knife slides through with no resistance.
2. While hot, mash the taro until very smooth with a potato masher or fork.
3. Warm the coconut milk with the sugar, salt and pandan leaves, stirring until the sugar dissolves. Remove the pandan and mix the coconut milk into the mashed taro until smooth.
4. Whisk the tapioca starch and rice flour with the water until smooth, then stir into the taro mixture to a thick, smooth batter.
5. Oil a 20 cm square tin. Spread the batter in evenly and smooth the top with an oiled spatula. Cover the tin loosely with foil or wrap the steamer lid in a cloth.
6. Steam over high heat for 40–45 minutes, topping up with boiling water as needed, until the cake is firm and a skewer comes out clean.
7. Cool completely in the tin, at least 3 hours.
8. Turn out, cut into squares with an oiled knife and roll each piece in the coconut.

v. Tips & common mistakes

• Protect your hands. Gloves or oiled hands prevent the itch from raw taro.
• Cook the taro right through. Under-steamed taro gives a lumpy batter and a scratchy aftertaste.
• Mash while hot. Cold taro turns gluey and lumpy; hot taro mashes smooth and fluffy.
• Keep condensation off. Drips from the lid pit the surface; cover the tin or wrap the lid.
• Cool completely before cutting. Warm, the cake is sticky and will not cut cleanly.
• Don't refrigerate. Taro and starch harden in the fridge. Keep it covered at room temperature and eat within two days.

vi. Variations

Layered taro cake alternates taro and plain coconut layers. Taro and sweet potato cake uses half orange sweet potato for colour. Thai-style versions use more coconut cream and sometimes palm sugar. The savoury Cantonese wu tau gou uses rice flour with Chinese sausage, dried shrimp and spring onion, and is pan-fried to serve. Some cooks add steamed taro cubes to the batter for texture.

For other steamed sweets, see Filipino puto and kutsinta; for taro's purple cousin ube, try ube ice cream; and for the Lunar New Year rice cake, nian gao.

vii. Serving & storage

Serve at room temperature, as a snack with tea or coffee, or as part of a plate of mixed kuih. It also appears at Lunar New Year gatherings and family celebrations.

Keep covered at room temperature for up to 2 days. If it firms up, re-steam squares for 5 minutes (before coating) to soften them. Do not freeze; the texture becomes spongy and watery.

ix. More from Chinese

• Nian Gao — Lunar New Year rice cake
• Mung Bean Cake — pressed bean pastries
• Coconut Jelly — set in the coconut shell
• Agar-Agar Jelly — layered pandan and coconut
• Seri Muka — pandan custard on rice
• Ube Ice Cream — purple yam ice cream