Castella (Kasutera カステラ) catches my attention when I realize that it is a cake made with bread flour. 

So is it a cake or bread? 

The Portuguese merchants introduced castella to Japan in the 16th century. It is derived from a Portuguese recipe Pão de Ló. Since it is also called Pão de Castela, meaning “bread from Castile”, the Japanese just called it kasutera. 

Although it is called “Pão’ in Portuguese, which means bread, it is more like a sponge cake than bread. 

When I dug deeper into how to make castella, I realized that there are various methods to prepare it. It was in fact quite confusing to me. 

So I decided to do some research on how this Japanese cake is made. 

Castella (Kasutera カステラ) catches my attention when I realize that it is a cake made with bread flour. In this article, I want to show you my journey to develop my castella recipe, highlighting some mistakes I made, and offer the solutions.

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Simple castella recipe, intricate techniques 

In this article, I would like to tell you my journey to develop my castella recipe, highlighting some mistakes I made, and offer solutions. 

I include my recipe at the end of this article, which I think is the best. However, there are still unanswered questions that I will explore and provide an update when I have found the answer. 

For now, this is the stable recipe that yields the best result, which took me many rounds of testing. 

This post has two sections. The first section is the nitty-gritty of how I prepare the Castella. The second section is all the mistakes I made and the solution so that you don’t make the same mistake again like me.

The difference between the Japanese castella and the Taiwanese castella 

The main difference between the Japanese and Taiwanese castella is the Japanese version includes bread flour in the recipe instead of regular flour, without butter and baking powder. Therefore, unlike the jiggly Taiwanese-style castella, it is springy, slightly gooey, and with a dark crust. You only need a few simple ingredients to get this attractive texture.

How to make the Japanese castella 

Castella has soft and tighter crumbs, more sturdy, slightly gooey, and bouncy thanks to the use of bread flour. The origin formula uses Mizuame, a Japanese starch syrup made from malt and rice. I substitute it with honey as mizuame is hard to get outside Japan. 

1. Make the meringue

There are two methods to deal with the eggs. You can beat the egg yolks and whites together, or beat them separately. Curious to know the outcome of these methods, I have made two batches of castella and compare the results. 

It turns out the castella prepared with meringue (beat separately) has a finer texture and smoother. Although I do not know precisely the reason, I suspect beating separately the egg whites yields a more stable meringue. 

Here are the steps: 

  • Separate the egg whites from the egg yolks. You can do it by your clean hands or with a yolk separator. Place the egg whites in a clean, oil-free large mixing bowl. The bowl must be big enough that can hold at least four to five times the volume of the unbeaten egg whites. There was once I underestimated the volume of the meringue expanded, and ended up overflown and had to abandon the meringue.
  • The bowl must be free from oil and without any trace of egg yolks, which can affect the volume of the meringue. 
  • Place the mixing bowl over a hot water bath to keep the egg whites warm. It is best when they reach about 40°C/100°F. The volume of the egg mixture will increase faster if the egg/sugar mixture is warm.
  • Beat the egg whites with an electric mixer at low to medium speed. Low speed is better than high speed as it yields a smoother meringue, although it takes slightly longer. 
  • When the volume of the egg whites increases, add the castor sugar slowly. 
  • The egg whites and sugar will eventually gain volume and turn into a white cream. The cream (now called meringue) will become thicker with continuous whisking. 
  • When the meringue is about to form soft peaks, pause every twenty seconds to avoid over whisking. 
  • Stop beating when the meringue forms soft peaks when you lift the beater. Under whisked meringue is unstable and will cause the cake to collapse. On the contrary, over whisked meringue will make the cake dense. Therefore, getting the right texture of the meringue is critical to the success of the castella cake. 

2. Add the egg yolks 

  • Add the egg yolks to the meringue one by one. I switch off the electric mixer and mix it manually with the attached mixing blade, but you can change it to a handheld beater. Whisk the egg yolk thoroughly until homogeneous before adding the next egg yolk. The meringue tends to deflate if you add all the egg yolks at one go. 
  • It is best to whisk in one direction to minimize forming large bubbles and deflate the egg white. 

3. Add the honey 

Next, add the honey and continue mixing in one direction until homogeneous. The amount of honey required is small, just enough to let the castella have the taste without making it too sticky. 

4. Add the bread flour 

Sieve the bread flour. Then add half of it to the batter.

Combine the flour with the batter by mixing it gently in one direction until there are no more lumps. 

Add the remaining flour and continue mixing. Try to pick up all the flour sticking on the mixing bowl until it becomes a smooth batter without lumps

5.  Add the milk 

Add the milk to the batter and mix evenly. Some Japanese recipes used sake instead.

Once it is smooth, stop mixing as over mix will deflate the batter further, causes the cake to have a dense texture. 

Scrape the mixing bowl with a silicone spatula to ensure all the flour has incorporated evenly with the batter. 

Slam the bowl onto the table whenever you detect any large bubbles. Slamming helps to break the bubbles to achieve a very fine texture. 

You can reduce the bubbles by forming smooth meringue with low-speed whisking and gentle mixing. 

Have a few more slams to get rid of any noticeable bubbles. 

6. Pour the castella batter from a high point

Line the base and the side of the cake pan with baking paper. 

Pour the batter into the pan slowly from the position one foot above the base. The impact of the batter onto the pan and the slow pouring action helps to break the bubbles. 

Fill the pan only up to sixty percent full to let the castella enough space to rise in the oven. 

Slam the cake a few more times to break any bubbles that you see. Break the smaller bubbles with the tip of a bamboo skewer or toothpick. 

6. Insulate the cake pan with cardboards 

Traditionally Castella is baked within a bottomless wooden frame. The cake will rise evenly when the sides are insulated.

Since I do not have the wooden frame, I wrap the corrugated cardboard with aluminum foil (to prevent the cardboard from catching fire) to form a frame that insulates the cake. You can see how it looks in the video. 

Another method is to form a square cake pan (disposable) by using old newspapers. Newspapers and cardboard act as an insulator, just like the wooden frame. Please watch the video in this post. 

I made the cardboard frame since it is troublesome to construct the cake pan with newspapers. 

7. Bake the castella to perfection

Preheat the oven to 160°C/320°F.

Before putting the cake into the oven, make sure there are no large bubbles in the batter. Leave up the cake pan and slam on the tables a few times to break those large bubbles. (Don’t be afraid to do this. it will not deflate the batter. ) Drawing some lines on the surface of the batter with a wooden skewer helps to break the smaller bubbles. 

Place the castella on the lower rack of the oven. Bake at 160°C/320°F uncovered for about 50 minutes

The actual baking time depends on many factors, notably the size of the castella and the position of the heating element. You need to make adjustments because every oven behaves differently. 

You can increase the top temperature to 200°C/390°F in the final ten minutes if the surface has not turned to the beautiful dark brown color.

Remove the cake from the oven when the surface changes to dark brown, and the wooden skewer comes out clean after inserting it into the cake. Another way to check the doneness is to press the surface lightly with your finger. It should bounce back like a sponge.

8. Unmold the cake

Lift the cake pan and drop a few times to the table. This method helps to minimize shrinkage. I experienced a more severe shrinkage if I do not bang it a few times right after removing it from the oven. The image below shows what happened. I do not have the answer to why this step is working. If anyone knows the reason behind, please let me know by leaving the comment below.

Got the answer! Thanks to our reader Nikhil and Christian, for providing the answer. You can read the explanation in the comment section.
Nikhil’s answer is on September 1, 2020, and Christian’s reply is on October 28, 2020.

The castella shrink badly if I DO NOT drop (bang) it a few time on the tabe right after baking.

The cake will start to deflate a little and forms some wrinkle lines after a minute. Overturn the castella on a cake board and let it be upended for a minute. This method helps to create a flat surface. 

Now turn back the cake. 

Shrink-wrapped the castella while it’s still warm. Place it in the refrigerator. Be careful not to let the cling wrap touching the surface. It will stick and ruin the surface. This storage method helps to retain the moisture. 

To serve, trim all the sides of the castella to make it a perfect rectangle. Cut into slices and serve.  

9. Storage 

You can keep the castella in the fridge for up to 5 days and freeze well up to a month. 

Other related cake recipes

If you like the castella, you may also want to check out another Japanese sponge cake recipe on this blog. Castella is very eggy and without butter. For those who like more buttery cakes, our butter cake is one of the popular evergreen recipes. Do also try the marble cake for a change!

Common mistakes in making castella (and how to avoid it) 

Here is a summary of all the mistakes I make before getting it right, every time. I want to share with you so that you will not make the same mistakes again. 

Problem #1: The mixing bowl is too small.

If you use a small bowl, the volume of the meringue will swell and overflow. Since changing the bowl halfway during whisking the meringue will cause it to deflate, I have to discard it and make a new batch. It is a messy experience. 

Remember, do not underestimate the volume.

Problem #2 The meringue is not smooth 

You need to be patient while whisking the meringue. You can speed up by using a higher speed, but that will churn out large bubbles that you do not want. 

If you whisk the egg whites with low speed, the meringue will be smooth and silky. There will be less large bubbles and only form microfoams that are stable, which is less likely to deflate during mixing and baking. 

Since the speed of my electric mixer is high even set to the minimum, I only attach one beater to whisk the meringue. 

Problem #3 The batter is not smooth 

You will not get a smooth texture if the flour is not mixed well. The final appearance of the batter must be completely smooth, without any lumps. I did not get the smooth texture initially because I am too concerned that mixing the flour longer will deflate the batter. 

Yes. Prolonged mixing will deflate the batter, but I would rather have a less spongy cake than a coarse texture, which affects the mouthfeel and appearance. 

If you prepare the meringue with patience, whisk at low speed, it will not deflate much even after mixing-in the flour thoroughly. 

Problem #4 The batter has too many bubbles 

Whisking the meringue at high speed and mixing-in the remaining items vigorously will create large bubbles. Avoid doing that. 

You can destroy the bubbles by:

  • Slam the cake pan onto the table.
  • Use a wooden skewer to break the smaller one. 
  • Pour the batter into the cake pan from one foot above. 

Problem #5 The cake collapse at the center

Underbaked castella will collapse at the center. Another reason is the meringue is not stable, and the large bubbles break during baking. 

Problem #6 The surface color is too light 

If you want to get the immaculate, caramelized dark crust like those crafted by the professional bakers, increase the top temperature of the oven in the last five to ten minutes to darken it quickly. The color changes quite fast, so you need to keep an eye on it regularly.

I have mentioned everything that I can tell you about my journey to make the castella. 

Now it is your turn to bake.

Good luck! 

Yield: 16 slices

Castella Recipe - How to make (with detailed instruction)

Castella recipe

Castella (Kasutera カステラ) catches my attention when I realize that it is a cake made with bread flour. In this article, I want to show you my journey to develop my castella recipe, highlighting some mistakes I made, and offer the solutions.

Prep Time 30 minutes
Cook Time 50 minutes
Total Time 1 hour 20 minutes



  1. Beat the egg whites over a hot water bath with the electric mixer.
  2. Add the castor sugar to the egg white in batches.
  3. Stop beating when the meringue forms soft peaks.Castella - meringue peak
  4. Add the egg yolks, one by one into the meringue. Mix well.Castella - egg yolks
  5. Add the honey, mix well.Castella - honey
  6. Add the sieved bread flour to the batter in two batches. Combine thoroughly.Castella - flour
  7. Add the milk and mix well.
  8. Use the silicone spatula to scrape the side of the mixing bowl to capture all the possible flour that has mixed well. Castella - spatula
  9. Prepare the cake pan lined with baking paper, and surrounded with corrugated cardboards wrapped with aluminum foil at all the sides. Pour the batter into the cake pan slowly from the position about one foot above the base. Slam the cake pan (with batter) onto the table to break the large bubbles. Use a wooden skewer to break the smaller bubbles on the surface.Castella - break bubbles
  10. Bake at 160°C/320°F uncovered for about 50 minutes. Castella - baking
  11. Remove from the oven and slam it on the table to reduce shrinkage. Overturn the cake upended for one minute to flatten the surface. Wrap with cling film and leave it in the refrigerator for half a day.
  12. Trim off the sides to make it a perfect rectangle. Cut it into slices and serve.

Nutrition Information:



Serving Size:


Amount Per Serving: Calories: 115Total Fat: 3gSaturated Fat: 1gTrans Fat: 0gUnsaturated Fat: 2gCholesterol: 108mgSodium: 39mgCarbohydrates: 17gFiber: 0gSugar: 11gProtein: 5g

This data was provided and calculated by Nutritionix on 5/9/2020

    31 replies to "Castella Cake – How to make (with detailed instruction)"

    • KP Kwan

      Hi, this is KP Kwan. I am happy to see you in this comment area, as you have read through my recipe. I am pleased to reply to any questions and comments as soon as possible.

      • Peck

        May I know why need to have water bath when bearing egg white?

        What is the reason of wraping the mould with aluminium foil ?

        • KP Kwan

          Hi Peck,
          1. The egg white will expand faster if it is warm and take a longer time to rise if it is cold. Therefore, I put a hot water bath beneath the egg white.
          2. I wrap the cardboard with aluminum foil for safety reasons, i.e., to avoid it catches fire in the oven.
          Thanks, and have a wonderful weekend.
          KP Kwan

          • Aj

            I am not a very experienced baker but I have a question.
            Do you know of any substitutions for cling rap? I try to avoid plastic usage.

            • Aj

              Also, is it fine for me to use brown sugar instead of white sugar. I’m sorry if that was a dumb question, I’m really not an experienced baker.

              Looking forward to hearing from you,


            • KP Kwan

              Hi Aj,
              I do not see the problem of using brown sugar. I think it will add more flavor! Just make sure to use the fine brown sugar, not those with large granules.
              KP Kwan

            • KP Kwan

              Hi Aj,
              The idea of using the cling wrap is to keep the moisture within.
              It will work the same if you can put the castella in large glassware and cover tightly. I hope that will work well.
              KP Kwan

    • Flora

      It looks so delicious… I think I will cook it for our anniversary in the morning to the coffee…

      • KP Kwan

        Thanks for using this recipe, and all the best!

    • Jennifer Tan

      May I know the reason of using bread flour instead of cake flour? I have tried many times on different recipes which using cake flour and even all purpose flour but never able to get a good rise. Every time, it will collapse after I removed it from the oven and slam it on the table. The bottom will usually end up dense even I tried to prolong the baking time to more than 90mins at 150 degrees Celsius. Your recipe seems to be different from the rest I saw so far. But I really scare to deflate the egg white by slowing adding the egg yolk and the rest of the ingredient to the meringue. And may I know how long you usually beat your egg white if you use the lowest speed? As I realised the lowest speed is quite slow. Thanks in advance for your advice on my queries.

      • KP Kwan

        Hi Jennifer,
        Bread flour is used in the Japanese version of castella. It has a more stretchy and bouncy texture with tighter crumbs. When you bite into it, you can feel some resistance like eating bread.
        If you use cake flour with lower protein content, the texture is more open and light. When you bite into it, it feels more like sponge cake rather than cake. That is used in the Taiwanese version. Both types of flour will result in a different texture.
        As for the egg white, I find that using low speed and longer time yields a more stable meringue. (than high speed and shorter time). If the meringue is stable, it can withstand slow pouring from a high position, and mix the rest of the ingredients.
        If your lowest speed is too slow, use the second-lowest.
        If the lower part of the cake is denser than the top section, try to put it on the lowest rack, or increase the bottom temperature a bit. Each oven behaves differently, so the temperature suggested in the recipe is only act as a guideline.
        I hope this information is useful.
        KP Kwan

        • Jennifer

          Thanks for your advice. I have been using the lowest rack to bake. And also unfortunately my oven doesn’t hv different setting for top and bottom temp. I hv done a research and someone said can use a lower temp and prolong the baking time. Or I actually thinking maybe for the last 10mins, I switch to bottom heat only. Juz need to try it out to make it works .

          • KP Kwan

            Hi Jennifer,
            That is a little tricky without the full control provided by the oven. I hope your perseverance in making it happens will solve the problem. Good luck, and enjoy the process.
            KP Kwan

    • doris

      May I know the dimensions of the cake pan you used for this?

      • KP Kwan

        Hi Doris,
        The size of the cake pan I used is 8″x8″ square.
        KP Kwan

        • Nikhil

          Hey, this is Nikhil
          Can you please tell me that how does dropping the tin after the cake is baked helps in reduction of shrinkage of it

          • KP Kwan

            Hi Nikhil,
            This step is based on my observation. Not a food scientist, but try to rationalize it. I think the impact causes the large bubbles within the batter to break. As a result, it removes the large empty air pocket inside to form a uniform and compact texture. The cake then becomes more stable during baking.
            KP Kwan

            • Nikhil

              Sorry, but i dint get you.
              I was asking you about the cake dropping after its baked and not the batter.
              About this statement of yours –

              “Remove from the oven and slam it on the table to reduce shrinkage. Overturn the cake upended for one minute to flatten the surface. Wrap with cling film and leave it in the refrigerator for half a day.”

              Thank you

            • KP Kwan

              Hi Nikhil,
              Sorry I misread your previous comment.
              I made one castella today without banging it after baking to see the result.
              It shrinks more than if I do not bang it a few times. I do not know the exact reason, but since this action is useful, so I keep doing it.
              I have added the images of this result in the article, in the section ‘Unmold the cake.’
              KP Kwan

            • Nikhil

              Thank you Kwan,
              I just got the answer while reading some blog and thought of sharing the answer.It goes like this –

              In “The Science of Cooking,” (available on Amazon) that Peter Barham claims to prevent a cake from collapsing as it cools, you have to drop it on the counter. He writes that cakes collapse as they cool because steam condenses in the cake bubbles.

              The cake bubbles shrink because air can’t get into those cake bubbles to replace the volume lost. Shrinking bubbles means shrinking cake, basically, and the shrinking occurs most towards the middle of the cake because the centre of the cake is softer, while the crust is too dry and stiff to contract.

              Barham goes on to offer a way of preventing cake collapse, specifically stating that “Dropping the cake, from a height of about 30 cm on to a hard surface, passes a shock through the bubble walls and allows some of them to break, converting the cake from a closed to an open cell structure. Now air is able to get into the broken bubbles and the cake will not collapse.”)

              Hope you find this useful.

            • KP Kwan

              Hi Nikhil,
              Thank you so much for getting the answer for me. I have been searching for the reason for some time. I will certain take a look at the book you recommend.
              KP Kwan

    • Christian Gross

      You asked why you need to slam the cake after the oven to avoid a shrinkage of the cake. I think I have an answer for you. I used to work in the foam industry (car seats). When foam seats are poured, they need to cure, and then after curing they are run through rollers to crush the seats. The reason is simple, foam is soft because the strands between the foam bubbles are broken. If you don’t do that the heated air bubbles will contract and pull the foam into a block.

      I am guessing the same thing is happening with the cake. The slam breaks the cake and allows the hot air to escape and keep the form.

      • KP Kwan

        Hi Christian,
        Thank you so much for providing the answer. Your answer confirms that the explanation given by another reader, who quotes an explanation from the book. You can read this in the comment section. Roll down to September 1, 2020, by Nikhil.
        KP Kwan

    • Elizabeth

      Your recipe is so detailed, so I found it more helpful than others i have tried. However, every time I make Castella, I can never get the meringue texture with soft peaks. It usually is more foamy and results it lots of bubbles and a more liquid consistency than it should be.
      Do you have any tips on how to fix this? Thanks so much.

      • KP Kwan

        I would try to use low speed to high speed as it yields a smoother meringue, although it takes slightly longer. Also, make sure the bowl is free from oil. I hope this is helpful.

    • kbdta

      ilove this Vlog about Castella! THank you KP Kwan and the commentors relies..I felt , I hve learned from the best professionals.. Thanks guys! Keep helping and rockin!!! Sharing idea from your experiences can make the world beautifuly awesome.

      • KP Kwan

        Thank you!

    • Mei

      Thank you so much for the advise. I will try your methods to see if it is successful. I want to bake cake for my mum.

      • KP Kwan

        All the best!

    • Pham Le

      Hi KP Kwan,
      Thank you very much for such good and detail instructions. I think the slamming tip does keep the cake from over shrinking. I baked this cake once couple weeks ago follow another recipe and would like to contribute some small tips in the final steps in hope that it would be helpful for everyone here.
      Just after removed from the oven, brush the surface with a honey wash (a little honey dissolve in warm water). Then immediately flip the cake upside down onto a nylon film, wrap it tightly while it still hot and place it in the fridge upside down at least 8-12 hours before serving. The heat trapped inside the nylon wrap will keep the cake moist, the honey wash not only give the cake surface a really nice deep brown color, but also protect the surface from the nylon film. Lastly, the upside down placing will keep the cake from being too dense at the bottom. They called this the “cake aging procedure” and said that the cake would definitely taste a lot better after aging.
      Hope those would contribute some nice tips to our bakers community here. : )

      • KP Kwan

        Hi Pham,
        Thank you so much for your generous sharing of your experience. I hope all the readers here will read your comment.
        KP Kwan

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