Baking & Pastry > Basic Baking Principles > Mixing Methods > Whisking Method (Sponge Cakes)

Japanese Sponge Cake (Castella)

Explore the unique and delightful texture of Japanese Castella cake, a sponge cake known for its moistness and subtle sweetness. This recipe adapts the whisking method to create a truly special treat.

Prep Time
25 minutes
Cook Time
40-45 minutes
Servings
6-8
Ingredients
  • 4 Large Eggs
  • 120g Granulated Sugar
  • 120g Cake Flour
  • 2 tbsp Honey
  • 2 tbsp Milk

Preparing the Ingredients & Pan

Preheat oven to 320°F (160°C). Line a square or rectangular baking pan (approximately 7x7 inches or 8x6 inches) with parchment paper, allowing it to overhang on the sides. This makes it easier to remove the cake. Combine honey and milk in a small bowl and warm slightly (microwave for 10 seconds) to make it easier to mix.

Whisking Eggs and Sugar (Hot Bath Method)

Place the eggs and sugar in a heatproof bowl. Set the bowl over a saucepan of simmering water (double boiler/bain-marie), making sure the bottom of the bowl doesn't touch the water. Whisk constantly until the mixture reaches about 104°F (40°C). This warming process helps to create a more stable and voluminous meringue.

Achieving Ribbon Stage

Remove the bowl from the heat and continue whisking with an electric mixer on high speed for 8-10 minutes, or until the mixture is pale, thick, and forms a stable ribbon when the whisk is lifted. This is crucial for the cake's texture.

Folding in the Flour

Sift the cake flour into the egg mixture in two additions. Gently fold the flour in using a spatula, being careful not to deflate the mixture. Mix just until the flour disappears; avoid overmixing.

Adding Honey-Milk Mixture

Take a small amount of the batter (about 1/4 cup) and mix it with the warmed honey-milk mixture. Gently fold this mixture back into the remaining batter. This helps to incorporate the moisture evenly and contributes to the cake's signature moistness.

Baking

Pour the batter into the prepared pan and gently tap the pan on the counter a few times to release any large air bubbles. Bake for 40-45 minutes, or until a toothpick inserted into the center comes out clean. The top should be a deep golden brown.

Cooling and Cutting

Remove the cake from the oven and let it cool completely in the pan. Once cooled, use the parchment paper overhangs to lift the cake out of the pan. Wrap the cake tightly in plastic wrap and refrigerate for at least 3 hours, or preferably overnight. This allows the flavors to meld and the texture to improve. Before serving, cut the cake into rectangular slices.

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FAQ

  • Why is Castella so moist compared to other sponge cakes?

    The addition of honey and milk, along with the overnight refrigeration, contributes to Castella's exceptional moistness.
  • What is the purpose of the hot bath (bain-marie) method?

    The hot bath helps to stabilize the egg whites and sugar, allowing them to be whisked to a greater volume and create a more stable meringue.
  • Can I use a different type of flour?

    While cake flour is recommended for the best texture, you can substitute it with all-purpose flour, but the texture may be slightly different. If using all-purpose flour, consider adding a tablespoon of cornstarch to help tenderize the cake.