Ingredients
Batter
- 6eggs, at room temperature
- 200 gcaster sugar
- 60 ghoney
- 30 mlwarm water
- 180 gbread flour, sifted twice
- 1 tbspmirin
For the tin
- a deep 20 cm square tin
- brown paper
- parchment
- granulated sugar, for the base
Directions
- Line a deep square tin with parchment and wrap the outside of it in brown paper. Castella bakes long and slow, and the paper insulates the sides so the edges do not set before the middle has finished rising.
- Scatter a thin, even layer of granulated sugar over the base, which becomes the characteristic gritty sugar layer on the bottom of a Nagasaki castella.
- Dissolve the honey in the warm water and set it aside.
- Whisk the eggs and sugar together over a pan of hot water until they reach about 40°C (105°F), then take the bowl off and whisk on high for 8 to 10 minutes, until the batter falls in a thick ribbon that holds its shape for a slow count of five.
- Whisk in the honey water and the mirin.
- Sift the bread flour in over three additions, folding it through with a whisk in a J-shaped motion.
- Bread flour, not cake flour. The higher gluten is exactly what gives castella its fine, close, faintly chewy crumb instead of the light airy one a sponge would have.
- Pour the batter into the tin from a height to break the largest bubbles on the way in.
- Tap the tin firmly on the worktop a dozen times, then drag a chopstick through the batter in a slow zigzag across and back.
- This debubbling is the whole difference between castella and an ordinary sponge. Uneven bubbles give a coarse crumb, and castella is prized for having no visible holes at all.
- Bake at 160°C (320°F) for 50 minutes to 1 hour, until deep brown on top and springy to the touch.
- Drop the tin once from a few centimetres onto the worktop to stop it shrinking back, then turn it out immediately onto cling film, top side down.
- Wrap it tightly while it is still hot and refrigerate overnight. This is not optional: the moisture redistributes and the crumb turns dense and moist. Eaten warm the same day, castella is dry and disappointing.
- Trim all four sides square and cut into thick slices.
Technique
- Bread flour, tapped-out bubbles, wrapped hot, rested overnight. Skip any of the four and it is a sponge cake instead.
- There is no butter or oil in it at all. The moisture comes entirely from the eggs and the honey.
- It arrived with Portuguese traders at Nagasaki in the sixteenth century as bolo de Castela, and Fukusaya has been baking it there since 1624.
Substitutions
- A wooden castella frame, which is what professionals use and which insulates better than paper.
- Golden syrup for honey, accepting that honey is most of the flavour and the substitution shows.
Variations
- Matcha castella, with 2 tbsp of matcha sifted in with the flour.
- Zarame castella, with coarse brown sugar crystals on the base.
- Made in a loaf tin as a smaller domestic version.
History
Brought by Portuguese traders to Nagasaki in the sixteenth century as bolo de Castela; Fukusaya has baked it there since 1624.
Frequently asked questions
What is Castella?
Castella is a bread & pastry from Japan: fine-crumbed honeyed sponge baked in a square loaf, Nagasaki’s souvenir cake. Brought by Portuguese traders to Nagasaki in the sixteenth century as bolo de Castela; Fukusaya has baked it there since 1624.
How long does Castella take to make?
Castella takes 30 min plus overnight resting of preparation and 1 hr of cooking. The recipe makes 1 loaf. It is rated hard to make.
What can I substitute in Castella?
Yes, within limits. A wooden castella frame, which is what professionals use and which insulates better than paper. Golden syrup for honey, accepting that honey is most of the flavour and the substitution shows.
What is the most important thing to get right in Castella?
Line a deep square tin with parchment and wrap the outside of it in brown paper. Castella bakes long and slow, and the paper insulates the sides so the edges do not set before the middle has finished rising.
