🍰 Fluffy Castella Sponge Cake – A Classic Refined
🧁 Introduction
Castella (Kasutera) is a delicately sweet, soft sponge cake known for its finely textured, bouncy crumb and shiny golden crust. Unlike airy Western sponge cakes, Castella is moist and slightly chewy, offering a satisfying bite with subtle richness. Our fluffy version brings a modern touch to this traditional treat—keeping its signature smoothness while boosting its lightness and height.
📜 Origin and Cultural Significance
Castella was introduced to Japan by Portuguese missionaries in the 16th century. The name comes from “Pão de Castela,” meaning “bread from Castile.” It quickly adapted to Japanese tastes and became a celebrated sweet in regions like Nagasaki, where it’s now a local specialty.
In Japan, Castella is more than just a cake—it’s a gift, a symbol of hospitality, and often enjoyed with tea or given on formal occasions. Its minimalist ingredient list reflects wabi-sabi aesthetics: elegance through simplicity.
🧾 Ingredients & Quantity
| Ingredient | Quantity |
|---|---|
| Egg whites | 6 large |
| Egg yolks | 6 large |
| Granulated sugar | 85 g |
| Vegetable oil | 80 ml |
| Cake flour (or sponge flour) | 90 g |
| Milk (room temperature) | 70 ml |
| Salt | 1/4 tsp |
Note: Use cake flour for the best tender texture. All-purpose flour may result in a denser cake.
➕ Optional Additions
- 1 tsp vanilla extract or honey for extra aroma
- 1 tbsp mirin or corn syrup (adds shine and moisture)
- Matcha powder (1 tsp) for a green tea flavor
- Lemon or orange zest for a fresh citrus twist
- Brown sugar or honey instead of white sugar for a deeper taste
✅ Tips for Success
- Separate eggs carefully. No yolk should mix with the whites or they won’t whip properly.
- Room temperature ingredients help maintain emulsion and volume.
- Sift flour twice to ensure an ultra-fine, lump-free batter.
- Use a water bath when baking to prevent cracking and keep moisture.
- Bake slowly at low temperature for a smooth top and even rise.
- Avoid overmixing when folding in flour; use gentle strokes to keep the batter airy.
👩🍳 Instructions
- Preheat oven to 150°C (300°F). Line an 8×8-inch square or loaf pan with parchment paper. Optional: wrap pan in aluminum foil if using a water bath.
- Separate the eggs. Place whites in a large bowl (or stand mixer) and yolks in another.
- Whip egg whites until foamy. Gradually add sugar and beat until stiff, glossy peaks form (meringue stage).
- Whisk egg yolks briefly, then gently fold them into the meringue in 2–3 batches.
- Combine oil and milk, then warm slightly (lukewarm). Slowly pour this into the egg mixture while folding gently.
- Sift in flour and salt in 2–3 parts, folding carefully each time. Avoid deflating the batter.
- Pour batter into prepared pan. Tap lightly to release bubbles.
- Bake in water bath at 150°C (300°F) for 50–60 minutes or until golden and springy. A skewer should come out clean.
- Cool in pan for 10 minutes, then remove and cool completely on a rack. For the traditional texture, wrap the cooled cake and rest it overnight in the fridge.
✨ Description
This fluffy Castella cake is a symphony of texture: the top is shiny and golden-brown, the crumb is tight but airy, and the bite is soft, moist, and slightly elastic. It’s rich without being heavy and sweet without being cloying—perfect for refined palates.
🧮 Nutritional Information (Per Serving, 10 slices)
| Nutrient | Approx. Amount |
|---|---|
| Calories | ~160 kcal |
| Protein | 4g |
| Carbs | 14g |
| Sugar | 8g |
| Fat | 10g |
| Fiber | 0.2g |
These values are estimates and vary depending on specific ingredient brands.
📝 Conclusion
The Fluffy Castella Sponge Cake is a testament to simplicity done right. With just a few pantry staples and a bit of technique, you get a refined dessert that works for everyday enjoyment or formal tea gatherings. Its elegant crumb, soft bounce, and lightly sweet flavor set it apart from Western-style sponge or butter cakes.
🌟 Recommendation
Serve with:
- A cup of green tea or genmaicha
- Fresh strawberries or whipped cream
- A dusting of powdered sugar or matcha glaze
Let it rest overnight wrapped in plastic — it gets even moister and more flavorful.
💚 Embracing Healthful Indulgence
While indulgent in taste, Castella can be made healthier without compromising quality:
- Substitute whole wheat pastry flour for a fiber boost
- Use olive oil or avocado oil for healthier fats
- Reduce sugar slightly or swap with coconut sugar
- Add chia seeds or flaxmeal for omega-3s (only 1 tsp max to avoid texture issues)
