What is castella?
Castella is prepared with simple ingredients: flour, eggs, and sugar, in equal quantities. However, the particular consistency of castella is due to a secret ingredient: thick malt syrup (mizuame).
A castella cake is authentic if it has the consistency of a damp sponge and has a light texture. Also, it is traditional to cut the sides of the cake to expose its soft, almost elastic crumb. The upper and lower surfaces of castella are preserved and are brown in color.
Some castella recipes use more egg yolks, which gives the crumb of the cake a much more pronounced yellow color. But all traditional castella cakes feature a clear contrast between the crumb of the cake and its upper and lower sides.
Also, the Portuguese recipe has evolved over the centuries: since the Edo period (isolationist period), malt syrup was used as a sweetener because sugar was scarce and expensive.
Nagasaki confectioners then developed the recipe of castella and adapted it to the taste of the Japanese. It is the introduction of malt syrup that gave this cake that refined touch that is not found in the Portuguese castella. This thick malt syrup is known in Japanese as mizuame.
Also, the real castella is very similar to the Portuguese pão de ló cake: it does not contain yeast or baking soda.
Moreover, castella does not contain any fat. Castella or kasutera owes its lightness to the presence of beaten egg whites, which gives it its typical sponge texture.
Castella (or kasutera), emblem of traditional Japanese pastry
Kasutera is a traditional Japanese pastry. It is a traditional Japanese wagashi type (和菓子) dessert.
The term wagashi was coined from the contraction of two Japanese words: wa, which means “Japanese” and kashi, which refers to a “candy” or “cake”.
Wagashi, traditional Japanese pastries, are different from Western pastries, known as yōgashi (洋菓子).
In Japan, it is common to eat wagashi with green tea. Wagashi are even very popular during the tea ceremony. Wagashi are classified according to their water content.
Many wagashi are made with rice flour and red beans. This is the case with the famous mochis, which are very popular today.
How to consume castella?
This cake is generally eaten in the form of rectangular slices. The difficulty lies in cutting regular slices. To be able to cut it into slices without difficulty, it is essential to place it in the fridge and make sure that the cake is completely cold.
Another tip to cut castella evenly: wipe the blade of a serrated knife with a damp cloth before cutting the slices.
The traditional castella of Nagasaki city is about 10 inches long. It is sold in a transparent and rectangular plastic box. But it can be in a smaller form: it is then called Iwamura castella.
Iwamura castella is not in the form of rectangular slices but in the form of small cakes baked in individual molds. Also, unlike the traditional castella, the edges of individual cakes are not removed with a knife.
What is the origin of castella (or kasutera)?
There are many controversies and legends about the origins of kasutera. However, it may well have its origins in a Portuguese recipe: pão de castela.
Indeed, the recipe for this Portuguese cake was reportedly spread by Portuguese missionaries in the city of Nagasaki at the end of the Muromashi period in the 16th century.
Nagasaki is a Japanese city located on the northwest coast of Kyushu Island. It is an emblematic port city that was the victim of the Allies nuclear attack in August 1945 during the Second World War.
Fukusaya (福砂屋) is one of the big pastry houses that started producing castella in Japan. This pastry shop was founded in 1624 in Nagasaki.
Over time, Fukusaya has improved its recipe to adapt it to the taste of the Japanese. Sugar being an extremely expensive and rare commodity during the Edo period (an isolationist period during which trade with foreign countries was prohibited), castella was once considered a luxury product in Japan.
To this day, it remains a prized dessert, and some major confectionery companies have perpetuated the recipe.
The Muromashi Era
In Japan, the Muromachi era (室町時代, Muromachi jidai) extended from 1336 to 1573. It marked the reign of the Shoguns Ashikaga dynasty. The term Shogun means “general” and refers to the military leaders in power.
The Muromachi period extends over two centuries and marks a period of transition from medieval Japan to the beginning of modern Japan. This period was also marked by recurring military conflicts and latency in political break-up. It was probably at this time that Portuguese Christian missionaries introduced castella to Japan.
What are the variants of castella?
Castella is found in different forms and variants in Japan. Indeed, sugar can be replaced by brown sugar. The most common version substitutes honey for the original malt syrup. Sometimes, cheese is even added.
The most exotic version of castella is green in color: it is called matcha castella. Indeed, green tea powder is introduced into the cake recipe. It then takes a light green-brown coloring, typical of matcha. This green tea powder is used in many desserts such as green tea ice cream, mochi, or even mochi ice cream.
Another version of this cake is also very popular in Japan: the chocolate castella. Cocoa powder is usually introduced into the recipe.
We hope that you will love this light sponge cake recipe. Malt syrup is undoubtedly an essential part of the recipe because it gives the cake its moist consistency.
- 6 eggs
- 1¾ cup sifted
- 1⅓ cup caster sugar
- ½ cup crystal sugar
- 5 tablespoons mizuame malt syrup + 3 tablespoons hot water
- Vegetable oil
- Separate the eggs.
- Melt the mizuame in 3 tablespoons of hot water.
- Line a 14-inch square pan (2-inch depth) with parchment paper, and sprinkle sugar on it.
- Preheat a convection oven to 320 F.
- In the bowl of a stand mixer, beat the egg whites at medium speed.
- Once the whites are firm, add the caster sugar in 4 times to make a meringue.
- Reduce the speed a little and, using the flat beater, incorporate the egg yolks one by one. Add the mizuame and mix.
- Add all the flour, and gently stir it with a spatula, without breaking the eggs.
- Filter the dough with a sieve.
- Pour the dough into the mold.
- Bake at 320 F for 40 to 45 minutes.
- At the end of baking, poke the cake with a toothpick. If the toothpick comes out clean, the cake is fully baked.
- Let cool without removing from the pan.
- When the cake has cooled slightly, cover it with an oiled parchment paper cut to the same dimensions as the cake.
- Turn the cake over onto a large serving dish.
- When it has completely cooled, remove the parchment paper and cut slices.