Kanom Tan (ขนมตาล)

The Cake That Ferments Itself

ขนมตาล splits into its parts: ขนม (a sweet) and ตาล — the toddy palm, a word Thai borrowed from Pali and Sanskrit tāla, the tree Thais once called โตนด. Ripe fruit from the female palm, mashed and sieved, goes into rice-flour batter with coconut milk; the batter is steamed in little cups and finished with grated coconut. No eggs, no wheat — Thai Wikipedia counts it among the few genuinely native Thai sweets, untouched by the western influence that reshaped most of the dessert table.

It is a Sukhothai-era sweet, and its home is Phetchaburi — the dessert town, ขนมเมืองเพชร — where the traditional version (ขนมตาลโบราณ, locally ปุ or ตะโหนดเต้า) is still wrapped in palm leaf. Its signature is the smell: faintly boozy, like fermenting wine. The original recipe used no raising agent at all. The fruit's own yeasts did the work, fermenting while the mashed flesh dripped in a cloth bag hung from the rafters — the step Phetchaburi cooks call เกรอะตาล.

Modern recipes shortcut that step. Wongnai and Kapook reach for baking powder and a ten-minute rest. Aroifin kneads in dry yeast and waits four hours. A Cookpad grandmother forbids the powder outright — mix and wait, she says, it rises by itself. Wikipedia notes why the original matters: market versions that skimp on the fruit and fake the yellow with dye come out hard and scentless — the exact failure the old way was built to avoid.

The Recipe (baking-powder home version, from Kapook — makes about 10)

The yeast route (Aroifin): same fruit, but 250 g rice flour plus 200 g tapioca starch, 1 kg coconut cream and thin coconut milk, 2 tsp dry yeast, baking powder dissolved in the thin milk only at the end, and a 4–5 hour rest. The traditional route (Krua): no raising agent — the mashed fruit is sieved, hung to drip about 8 hours (เกรอะตาล) while its natural yeast ferments it, and the flour is kneaded with coconut cream for a full 30–60 minutes. Wongnai's half batch: 200 g fruit, 250 g rice flour, 320 ml coconut milk, 200 g sugar — 5 servings, 300 kcal each.

The Method

1. The fruit. If you have fresh ripe palm fruit: peel it, mash the yellow flesh with a little water and a pinch of salt — the salt cuts the raw, astringent edge, per Krua's Phetchaburi cooks — scrape it through a sieve to shed the fibres, then squeeze it in cheesecloth and hang it to drip, up to 8 hours or overnight. From a tin: drain and mash; the work is done.
2. The batter. Dissolve the sugar in the coconut milk, then stir in the fruit. Add the rice flour and baking powder and stir smooth, then pass through a sieve. Rest 10 minutes — just long enough for the batter to set.
3. The long rest — the yeast way. For the fermented version, skip the powder: knead the flour with the coconut milk well (Krua insists the kneading is what makes the cake tender — at least 30 minutes), add the fruit and sugar, cover, and leave 3–4 hours until the batter foams on its own. Cookpad's grandmother is right: no powder, just patience.
4. The cups. Arrange your little cups in the steamer — banana-leaf cups (กระทงใบตอง) or the Thai clay cups called ถ้วยตะไล — and steam them empty for one minute first. Aroifin and Wongnai both use this trick so the cakes will not stick.
5. The coconut. Fill each cup to the top. Kapook and Cookpad sprinkle the salted grated coconut on before steaming so it bakes in; Aroifin and Wongnai scatter it on the finished cakes. Either way, the coconut is not optional.
6. The steam. Steam over boiling water on high heat for 15–20 minutes, then cool and unmould. Serve warm or at room temperature — the cake should be springy, not wet.

Where Thai Sources Disagree

How Western Versions Get It Wrong

• Eggs, butter, and the oven. Kanom tan is steamed, rice-flour, and eggless — Wikipedia's whole point is that it is one of the few Thai sweets with no western influence. Baking it as a sponge muffin is a different dessert wearing the name.
• Wheat flour. The batter is แป้งข้าวเจ้า — rice flour, not glutinous, not wheat. Swap in plain flour and you get a steamed scone.
• Yellow colouring instead of fruit. This is the exact sin Wikipedia scolds market vendors for: skimping on palm fruit and dyeing the batter yellow. The colour should come from the fruit, and the aroma is the point of the dish.
• Pumpkin, mango or pandan stand-ins. Palm fruit is not replaceable with a puree of something else. The fruit's fermenting yeasts — the thing that makes the traditional version rise — live in the palm fruit, not in a pumpkin.
• Skipping the rest. Powder-only batters need their ten minutes; yeast and natural batters need their hours. Stir-and-steam immediately gives a dense, flat puck — the thing Krua says modern shortcuts were invented to produce.
• Custard texture. The finished cake should be springy — Thai writers reach for เด้ง and หนุบหนับ, bouncy and chewy-soft. A wet, custardy centre means under-steaming or an overload of coconut milk.

UK Ingredient Notes

• Palm fruit: fresh toddy palm fruit is not sold in the UK — buy tinned palm fruit in syrup (ลูกตาลในน้ำเชื่อม) from Thai and Southeast Asian grocers or online Thai supermarkets, drain it, and mash. Tinned fruit sits in syrup, so cut the added sugar by a third to a half and taste the batter.
• Rice flour: regular white rice flour (แป้งข้าวเจ้า) — the free-from aisle of any UK supermarket stocks it. Not glutinous rice flour, not the gluten-free blend.
• Coconut milk: canned full-fat, 400 ml; one can plus a splash covers the three cups.
• Grated coconut: fresh mature coconut for the topping is rare here — frozen grated coconut from an Asian grocer is the closest match; desiccated works but needs a few minutes in water first.
• The cups: Thai clay ถ้วยตะไล are online, but small ramekins, dariole moulds or silicone cupcake liners steam identically. Banana leaves come frozen at Asian grocers if you want to make the leaf cups.
• Plan around the rest: the powder version is done in under an hour; the fermented version needs its 3–4 hours, so start the batter before lunch and steam after.

Sources

This recipe is translated from the following Thai-language sources. Where they disagree, we've said so.