What Taiwanese sponge cake is
Taiwanese sponge cake, often sold as Taiwanese castella or “ancient-style” cake, is a very soft, mildly sweet egg cake with a delicate jiggle. It is made by folding an egg-yolk batter into a stiff meringue, then baking it gently in a hot water bath so it stays moist and fine-textured. There is no frosting: it is eaten plain, sometimes warm, sometimes chilled.
Castella itself has Portuguese roots in the Nagasaki region of Japan. Castella also shows up in our Japanese banana cake. Taiwanese versions are generally described as lighter, softer and less sweet than the Japanese original, but recipes differ from baker to baker.
Castella vs sponge cake
A Western sponge such as a Victoria sponge is usually baked at a higher temperature, has a defined golden crust and a springy crumb, and is filled with jam or cream. Castella-style cakes differ in a few ways:
- They are baked at a lower temperature, often with a water bath, for a gentle, even bake.
- The batter includes a little milk and butter or oil warmed into the flour.
- The texture is wetter and more “melting” rather than airy and crumbly.
- They are usually served plain rather than filled.
If you want the more traditional style, see our jam sponge cake recipes.
Ingredients
A small batch for roughly a 15 cm (6 inch) round or square mold, based on commonly published ratios:
- 40 g cake flour
- 35 g butter
- 30 g whole milk
- 30 g granulated sugar
- 2 eggs, separated, at room temperature
- 1/4 teaspoon vanilla extract
- 1/4 teaspoon cream of tartar (or a few drops of lemon juice)
Multiply the amounts for a larger mold. These quantities are small, so use scales and a deep mold lined with baking paper on the bottom and sides.
Method
- Prepare. Line the mold, and set up a roasting pan large enough to hold it with room for hot water. Heat the oven to about 150°C (300°F).
- Warm the butter and milk. Heat gently until the butter melts. It should be warm, not boiling.
- Make the yolk batter. Sift the flour into a bowl, pour in the warm milk and butter, and whisk to a thick, smooth paste. Whisk in the yolks and vanilla. Avoid beating in extra air bubbles.
- Whip the meringue. Beat the whites with the cream of tartar, adding the sugar gradually, until you have a fine, glossy meringue with medium to stiff peaks. This step determines the softness of the cake.
- Fold. Add the yolk batter to the meringue in two or three parts, folding from the edge with a spatula until no streaks remain, while keeping the batter light.
- Fill the mold. Pour in the batter, tap the mold on the counter, and pop any large bubbles with a skewer.
- Bake in a water bath. Set the mold in the roasting pan, pour in hot water to come part-way up the sides, and bake for about an hour. A final 7 to 10 minutes out of the water, as some bakers do, helps dry the surface slightly. Baking times vary by oven and mold size, so check that the top is set and a skewer comes out clean.
- Cool. Remove from the mold and paper soon after baking, which helps avoid a wet or shrunken cake. Serve warm or cooled.
Troubleshooting
- Cake shrinks or sinks. Often caused by an under-whipped meringue, an overly hot oven, or leaving the cake in the mold too long after baking.
- Cracked top. The oven may be too hot. Lower the temperature slightly and make sure the water bath stays hot.
- Dense or rubbery layer at the bottom. Usually the batter was not folded evenly, or the yolk mixture was too cool and thick.
- Wet texture. Bake a little longer, or finish out of the water bath.
Storing and serving
Store covered in the refrigerator for a few days. Many people like it slightly warmed or at room temperature. A dusting of powdered sugar, a little honey or fresh fruit is a simple finish. Honey-forward baking in another style is covered in our Portuguese honey cake article.
FAQ
What is the difference between castella and sponge cake? Castella is baked low and slow, often in a water bath, and has a moist, dense-yet-soft texture, whereas regular sponge is lighter, drier and usually filled.
Why is pineapple cake famous in Taiwan? Taiwanese pineapple cakes are small shortcrust-style pastries with a pineapple filling, widely sold as gifts and souvenirs. They are a different dessert from sponge cake.
What was Queen Elizabeth’s favourite cake? Reports often say a chocolate biscuit cake, which is a no-bake dessert, not a sponge.
How do I make a basic sponge? You need eggs, sugar and flour, plus fat in creamed versions. The key is trapping air and folding gently.