Matcha Castella - Japanese Sponge Cake

I have to admit that I am not a big fan of the Castella Cake but I have been really inspired by Ju's (Little Teochew) pictures that I decided to give this a try.

I had eaten the Castella a few times more than 10 years ago. I can no longer remember the taste nor the texture of the cake possibly because I was not really partial towards it. I vaguely remember that it was too sweet for my liking. In fact, when I was in Tokyo in Feb last year, I had contemplated whether to buy some home ( they do look really elegant) but decided against it for I was afraid of the sweetness. I am very mindful about the level of sweetness in the cakes and cookies I bake because my family generally do not take well to sweets. My mum is diabetic and my vegetarian sister, who would talk to me about biodynamic food, continues to pester me to use wholemeal flour and eliminate sugar altogether.    (She just does not understand that cooking is Science, you just can't eliminate certain ingredients without affecting the stability, texture and taste of the final product!)

I made 2 attempts at baking the castella with Makiko San's recipe posted in Just Hungry. My first attempt used her exact recipe with Honey, which is the traditional Castella flavour. I took the cake out of the oven 20 mins too early. The positive part about this was, it yielded a very soft and moist texture but the surface layer was somewhat soggy especially after I had brushed the honey water syrup over it. And... it was too sweet for my taste.

In my second attempt, I decided to modify Makiko's recipe by cutting the sugar by 30% and adding matcha powder to it. Hence, by doing this, I was actually eliminating 30% of the sweetness from the sugar and the sweetness from the honey as well. This time, I also made sure that I baked the cake for 50mins as recommended by Maki.

The end result is a fragrant sponge cake which is not too sweet but I think if I were to repeat this again, I would bake the cake for 40mins to get a more tender texture. My matcha castella tastes suspiciously like steamed egg sponge. (???) I wonder if the texture will become finer if I were to use a mixture of bread flour and plain four. I feel there is too much 'gluteny' feel to the cake. Also as I scrutinised Castella maker, Fukusaya's website (link kindly provided by Ju), I noted that their process called for beating the egg white and egg yolk separately.

A note of appreciation - both Ju and Maki's emphasis on being patient and diligent cannot be overstressed. I never liked to work with whole egg sponge because when I tried to do these in the past, the texture would invariably end up coarse and dry. For the Castella, I had deliberately willed myself to be patient (no credit to being diligent. My stand alone mixer did all the whisking for me) and whisked the egg and sugar at low speed until a firm foam is achieved. I am really pleased with the texture of the cake. I am already contemplating about baking my next swiss roll using the same method.

I guess, what remains now is for me to get a block of Castella during my next trip to Japan in order to understand how it should really taste like.

I am posting my modified recipe here. But I would strongly recommend anyone interested in giving this a go to refer to Maki's detailed instructions. Of course, Ju's lovely pictures will provide the extra motivation should you choose to dither...:-)

Recipe :
(I halved the recipe featured in Maki's blog)

4        eggs
100g  brown sugar ( original recipe featured 150g of cane sugar)
50ml  milk

100g  bread flour
10g    green tea powder

For detailed baking instructions, please refer to Just Hungry's blog.