Chocolate castella cake

Since this post that compares the different type of castella cakes, I have tried the standard recipe here. It came out mostly successful but the bottom was gummy. Y suggested that it was because my oil hadn't been heated up high enough, and I think it was because I didn't follow the steps correctly. 

I was making halfway when the electricity went out and so stalled after the flour had been beaten into the yolk. Luckily no ill effect.

That was a recipe for 7 eggs in a 8" square pan. I looked around and most other recipes were either 5 or 6 eggs in the same size and shape pan. I decided to adapt 3 recipes for this attempt, mostly based on how spongey the final product looked in the video. The methods were mostly the same except one added the egg yolks before milk, another added the milk before the yolks, and a third didn't even have any yolks. The baking temps and timings were mostly consistent at 150 deg C but I thought I'd increase by another 2 minutes given my experience with uncooked bottom the last time.

Sources: Laura's Kitchen, Apron, and Table Diary. This recipe largely follows the ingredients from Apron but the methods from Laura's Kitchen and Table Diary.

Ingredients (20cm or 8 inch square tin)

6 eggs, separated

70ml oil

28g cocoa powder

60g cake flour

90ml fresh milk, fridge cold

½ tsp vanilla

¼ tsp salt

75g sugar

splash of lemon juice

Method

1. Separate the eggs when cold. If possible, put the egg whites back into the fridge to chill.

2. Prepare the tin by lining outside with aluminium foil and the inside with parchment.

3. Bring the oil up to between 70 to 80 deg C. I found that heating it for about 1 minute on high already brought it up to 100 deg C (!) so heat on low fire for approx a minute and check with a thermometer. Don't guess cos you won't guess correctly!

4. Sift the flour, cocoa powder, and salt into the oil. Mix well with a spatula.

5. Add half of the cold mix and mix, follow by the other half. Ensure no lumps remain. The mixture may be claggy at this point, that's normal.

6. Add one egg yolk at a time and combine well. At the end of the all the yolks, the mixture should be silky smooth. Set aside.

7. At speed 2, beat the egg whites with lemon juice until foamy. Add the sugar in 3 batches and turn up to speed 4. Once all the sugar has been added, increase the speed to between 6 to 8. Just before it reaches soft peaks stage, turn down to speed and beat for 1 minute to remove the big air bubbles.

8. Add ⅓ of the meringue into the chocolate batter. You can be rather rough and not worry about the air as  the point at this stage is to lighten the chocolate batter and to mix it well. 

9. Add the next ⅓ of the meringue and use either a whisk or spatula to fold well, taking slightly more care not to knock out all the air.

10. Pour the batter back into the remaining ⅓ of meringue and this time, slowly but carefully fold until no more white streaks remain.

11. Pour into the prepared tin. Drop the tin onto the countertop from about 5 cm heigh to knock out the air bubbles.

12. Place the tin into a larger tin, and pour hot water into the larger tin. (I didn't bother with this step because I had put the larger tin and room temp water in the tin to pre-heat in the oven, and sat a rack on the larger tin. So when the oven was sufficiently hot, I put the smaller tin on top of the rack of the larger tin) Ensure that your foil is above the water line so that no water goes into the cake tin.

13. Bake at 150 deg C for 62 minutes. Remove from oven and de-pan. Remove the parchment. Allow to cool down before carving.

Recipe feedback: 

- I could do with another say 10g of sugar as it wasn't as sweet as I'd like, but this is a Korean recipe and maybe they're less into sweet stuff? Who knows. I chose this recipe because it had the lower amount of sugar compared to the rest so I should have expected this. But I can live without the additional sugar.

- The recipe is perfect! The additional 2 minutes just EXACTLY dried out the cake without making it dry.