Finally, I am getting everything right on how to make the Japanese sponge cake after many attempts.

The cake is bouncy like a sponge, with the soft and delicate texture resemble cotton when you tear it apart.

I also add the cake batter to the dough of the chocolate Japanese milk bread. Here is the result- my delectable bread-cake that I missed so much after the nearby bakery decided to stop producing it.

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How to make Japanese sponge cake in twenty minutes

This article is all about how to make the Japanese sponge cake. Please refer to this article to find out how to make the Japanese milk buns that are incredibly soft.

The process of making the Japanese cotton sponge cake is similar to most of the sponge cake recipes. Nevertheless, there are some fine details which I will explain in detail in the following sections.

1. Measure the flour and butter correctly

The importance of sieving the flour

Measure 100g of plain flour and sieve at least once. What I mean by plain flour is any wheat flour that is label as cake flour or all-purpose flour. The percentage of gluten in these type of flours is relatively low, about eight to ten percent, which is ideal for making sponge cakes.

I sieve the flour not because it is dirty. The flour that I get locally are very clean, but I want to ensure that it is free from any lumps and large particles. The fineness of the flour is critical to get the cottony texture. If you happen to get any superfine cake flour, go for it. It will significantly improve the texture of the cake. Since I have not been able to purchase it this time, I have to sieve the flour to make sure the cake will turn out well.

Use melted butter to mix with the flour

Place 75g of unsalted butter in a pan/pot over low heat until it melts. You can melt the butter in the microwave oven by using low heat for a minute. Keep an eye to the butter and do not brown it as it will alter the flavor and smell of the butter.

You may want to substitute the melted butter with corn oil. However, a sponge cake made with good quality butter has a better flavor.

Add the flour to the melted butter after it is cooled. We do not want to add the flour to the hot butter to avoid the flour being cooked at this time. We are not here to make choux pastry!

Do not worry if the flour and the butter forms a sticky mass at this point of time. It will turn into a smooth batter after adding milk and the egg yolks subsequently.

Note: This is not a gluten-free formula. I have not tried to make a sponge cake with any gluten-free recipe so far.

2. Add the milk

Add 60ml (4 tablespoons) of milk to the flour-butter mixture. You may pour all the milk into the mixture or add in batches. It will not make any difference to the result.

The milk will dilute the flour-butter mixture to form a thick paste.

3. Separate the egg yokes from the egg whites carefully

We need to add the egg yolks to the above flour-butter-milk paste to form the batter.

So far the process is relatively straight forward. There is quite easy and does not involve much technique. However, please pay attention when you separate the egg yolks from the white. It can be the make or break step for this recipe.

Do not even let a trace of egg yolks contaminate the egg whites. We need pure egg whites to prepare meringue, and it has to be free from oil to be successful. Egg yolks are oily, and that is why it has to be very careful not to break the yolks.

Here are my recommended steps:

  • Use a clean stainless steel bowl to keep the egg whites. Wipe the bowl with paper towels to make sure that it is free of oil. The bowl must be large enough as we will use it to beat up the egg whites to form the meringue.
  • Use the egg yolk separator to remove the egg white from the yolk. I always crack the egg in a separate bowl to make sure any broken eggs will not contaminate the bulk of the whites.
  • It is not possible to separate all the whites from the yolks. However, there should not be even a trace of yolk in the white as it will hinder the expansion while making the meringue.

4. Making the batter

Lightly beat the egg yolks and add to the flour-butter-milk mixture.  Again I have tried to add the egg yolks in batches to the mixture, but it makes no difference compare to pouring all the yolks at one go.

The egg yolks will dilute the paste further into a batter. It is at this time that you need to mix it thoroughly. I mean to mix it, not to beat it as beating will create bubbles that are not a welcome inclusion to the cotton-like texture.

Mix it in one direction until it is free from any visible lumps. The final batter should have a very smooth texture.

Once you have done that, you have won half of the battle. Let’s move on to prepare the meringue.

5. Beat the egg whites until it forms stiff peaks

The egg white should be at room temperature while making the meringue. Remove the eggs from the refrigerator and wait for it to return to the room temperature before cracking them.

Beat the egg whites with a hand-held mixer at low speed. If the room temperature is too low during winter, place the bowl of egg whites on a hot water bath. Warm egg whites can trap more air in its structure and expand its volume rapidly during the beating process.

  • Add 80g of castor sugar or fine sugar into the egg white after fifteen seconds of beating.
  • Continue beating the egg whites until the volume triple. The egg white will change gradually from transparent to pure white, and become thicker.
  • Eventually, the egg whites become so thick that when you switch off the electric beater and turn it upside down, the egg white that sticks onto the beater blade will become so stiff that it will firmly stand without drooping. Beat the egg whites until it can form a stiff peak.

Nevertheless, some bakers prefer to beat the egg whites to form a soft peak, which means that the peak will droop a little when you overturn the beater blade.

How to maintain the best volume for the meringue

If the meringue forms only until the stage of the soft peak, it will lose volume rather quickly while you start to fold since it is less stable. In contrary, meringue that forms stiff peak stage is firmer and need more folding until it can incorporate uniformly with the batter. The longer you fold, the batter will deflate more.

My preference is first to beat it until it forms a soft peak, then beat further by stopping every twenty seconds to check if it achieves the stage of stiff peak. I do not want to overbeat it because the meringue is hard to combine with the batter once it becomes too stiff.

I will dilute the batter with a quarter of the meringue so that it is easier to mix, then add the diluted batter back to the bulk of the meringue. Fold the meringue into the batter slowly until it is almost homogenous.

The batter will deflate beyond the optimum level if you fold the meringue until the batter is homogenous.

Then I will pour the cake mix into the cake pan. The pouring action will finish up the last bit of mixing which will eventually produce a homogenous cake mix in the pan.

Japanese sponge cake is bouncy like a piece of sponge, with the soft and delicate texture resemble cotton when you tear it open. This articles will show you every detail of how to make Japanese cotton sponge cake. (with video).

6. Line the cake pan with baking paper

Line the cake pan with a large piece of baking paper enough to cover the sides of the square cake pan. Brush the paper with some melted butter.

Since I am using a cake pan with a detachable base, I have to wrap the exterior of the pan with aluminum foil to avoid the water from the water bath from seeping into the pan.

After pouring the cake mix into the pan, you will notice there will be some bubbles on the surface. These bubbles will create little craters on the surface if you do not get rid of them. You can do this by:

  • Gently tap the cake pan a few times to break the large bubbles.
  • Use a bamboo skewer or toothpick to break the smaller bubbles.

7. Baking at the right temperature

Place the cake in the hot water bath. Once the oven is heated, bake at 150°C/300°F for sixty minutes.

But it may not be right sometimes!

The recommended temperature and baking time is one of the most unreliable measurements in any recipes for cakes. Most of the ovens do not have a very accurate temperature indicator. The heat distribution and the size of the oven is another factor that affects the final result.

My suggestion is to take a quick look at the cake after baking for forty minutes. If the cake has already expanded, then it should be fine. Otherwise, increase the temperature by 10°C to make sure the air trapped in the batter expands and push up the cake.

When the cake is nearly done, you can open the oven door more often without worrying the sudden drop of temperature will cause the cake to deflate. Check the color of the cake. The actual baking time will depend on the color of the cake. You need to check. It is not possible to set the temperature precisely each time unless the oven has a digital control panel.

8. Do not cut the cake immediately after baking

Remove the cake from the oven and water bath and let it cools on the table for fifteen minutes. The cake will shrink a little and detached from the sides of the pan.

Overturn it onto a wire rack and remove the paper. Then, place a cake board on it and revert the cake again. Now you have Japanese sponge cake ready to cut and serve.

Variation: How to make Japanese sponge “cake-bread”

I also combine this recipe with the Japanese milk bread published in this blog to create a cake-bread loaf. You can refer to the bread recipe article to make the bread. I have added a teaspoon of cocoa powder to change the bread to a chocolate color.

To do this. Place a small dough of the bread into a loaf pan. Pour the sponge cake mix on the dough after it doubles in size. Bake as the same temperature and duration in the sponge cake recipe. 

Yield: 1 cake cut to 9 portions

Japanese Sponge Cake

Japanese Sponge Cake

Japanese sponge cake is bouncy like a piece of sponge, with the soft and delicate texture resemble cotton when you tear it open.

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


  • 100g cake flour
  • 75g melted butter
  • 60ml milk
  • Vanilla extract (optional)
  • 6 large eggs
  • 80g castor sugar


  1. Measure the plain flour and sieve a least once. 
  2. Add the flour to the melted butter after the butter is cooled. Mixed well.
  3. Add the milk. Mix well.
  4. Lightly beat the egg yolks and add to the flour-butter-milk mixture. Mix it thoroughly. 
  5. Beat the egg whites with a hand-held mixer at low speed. 
  6. Add the sugar into the egg white after about fifteen seconds of beating.
  7. Continue beating the egg whites until it can form a stiff peak.
  8. Add a quarter of the meringue to the batter to dilute the batter so that it is easier to mix, then add the diluted batter back to the bulk of the meringue. Fold the meringue into the batter slowly until it is almost homogenous. 
  9. Line the cake pan with a large piece of baking paper. Brush the paper with some melted butter.
  10. Pour the cake mix into the pan.
  11. Gently tap the cake pan a few times to break the large bubbles.
  12. Place the cake in the hot water bath. Bake at 150°C/300°F for sixty minutes.


If you encounter any audio / visual problem of viewing this video, you can view it from YouTube by clicking this link, which will open in a new tab.

Nutrition Information:



Serving Size:

1 cake cut to 9 portions

Amount Per Serving: Calories: 187 Total Fat: 10g Saturated Fat: 5g Trans Fat: 0g Unsaturated Fat: 4g Cholesterol: 142mg Sodium: 105mg Carbohydrates: 18g Fiber: 0g Sugar: 9g Protein: 5g

Japanese Sponge Cake

Items you may need for this recipe.

Klee Premium mixing bowls Set of 6 - stainless steel mixing bowls - Polished Mirror kitchen bowls - Set Includes ¾, 1.5, 3, 4, 5, 8 Quart - Ideal For Cooking & Serving - Easy to clean - Perfect gift

Photo Credit:

Resistant to dents and rust, these mixing bowls are durably crafted of high-quality, heavy-gauge stainless steel to provide long-term strength and ensure you get extensive use out of them for years to come.

Hamilton Beach 62682RZ Hand Mixer with Snap-On Case, White

Photo Credit:

Snap-on storage case,
250 Watts peak power,
Bowl Rest feature,
Six speeds with QuickBurst button,
Traditional beaters and whisk.

Hiware 9 Inch Non-stick Cheesecake Pan Springform Pan with Removable Bottom/Leakproof Cake Pan Bakeware with Cleaning Cloth

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Perfect for cheesecake, mousse, quiche and more, this 9" springform pan is an essential item in any baker’s kitchen

Ultra Cuisine 100% Stainless Steel Wire Cooling Rack for Baking fits Half Sheet Pans Cool Cookies, Cakes, Breads - Oven Safe for Cooking, Roasting, Grilling - Heavy Duty Commercial Quality

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HEAVY DUTY STRONG WIRE GRID - with small holes, smooth no-snag edges, and a full 1-inch height resulting in greater all-around air flow and even cooking and cooling every time

    17 replies to "Japanese sponge cake – How to make the most cottony and bouncy cake"

    • 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 glad to reply to any questions and comments as soon as possible.

      • Gbemi

        Cant wait to make this,but first, what is a hot bath & secindly what if j dont have a hand held beater? Can it come out the same? Pls help,thanks

        • KP Kwan

          Hi Gbemi,
          1. Put the cake pan in another larger container, which contains some hot water before baking. (Please watch the embedded video at 5.06 minute).
          2. Handheld beater in basic equipment that you need to purchase to make the cake. Please buy one.
          KP Kwan

    • Lily

      Hi Kwan, may I know the dimension of your square cake pan?

      • KP Kwan

        I am using 8×8 inches cake pan.

    • Gloria

      Can you list the amounts in cups, tsp, tblsp etc?

      • KP Kwan

        Hi Gloria,

        Thanks for your comment.

        Since each ingredient has different density, it turns out there’s no standard conversion.

        The reason for me to use grammage is because that’s the most accurate measurement. However, you can convert all the ingredients by using the following conversion service :

        Hope you this is useful to you.

        KP Kwan

      • Saheefa Nadeem

        Could i use ghee instead of butter?

        • KP Kwan

          You can, but the difference is minimal.

    • Rupnarayan

      It looks so yummy. I will try to make this Japanese sponge cake.

      • KP Kwan

        Rupnarayan you are welcome. Enjoy the cake 🙂

    • Ritika

      AMAZING! it looks delicious and mouth-watering cake recipe. I will surely try this recipe on my father’s birthday. and I’m sure he would really like it a lot.

      • KP Kwan

        Hi Ritika,
        Thanks so much for trying the recipe 🙂
        KP Kwan

    • Bui

      How many eggs please?

      • KP Kwan

        6 Eggs. You can find this in the recipe.

    • Cirilo Howard

      i will try this at home, thank you.
      it is interesting how the cake rises without any baking powder or leavening.

      • KP Kwan

        Yes. That is how the sponge cake is. It depends on the air trapped in the egg white to raise the cake. If you add a small amount of baking powder, it will enhance it further, and that is called chiffon cake.

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