Why Do Cupcakes Sink Or Overflow? | CoachSweetTooth

Cupcakes are the most versatile and delicious desserts. However, one of the most common questions that beginner bakers ask is why do cupcakes sink or overflow.

When you are learning how to bake, it is important to follow the recipe to the letter. However, even bakers who do that often struggle with creating the perfect cupcakes because even a single ingredient that has gone off or a one tiny step that was skipped can lead to big repercussions for your cake.

What makes baking so tricky is that cupcakes can sink or overflow for several reasons, including using expired or incorrect amounts of leavening agents, overmixing the batter, butter, or eggs, not following the correct oven temperature, underbaking, overfilling the cupcake liners, and more.

Making sure your cupcakes do not sink or overflow is an important step in getting perfectly turned-out cupcakes. In this guide, we will help you explore the most common reasons why cupcakes can sink or overflow, how to prevent these mistakes, and how to fix sunken or domed cupcakes.

As a person who loves to bake, I have experienced cupcake disasters way more than I have been able to bake successful cupcakes. It has been several years since I have started baking, but I still experience sunken, dense, overcooked, and domed cupcakes from time to time. However, each time is an opportunity to learn from my mistakes and become a better baker.

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Why Do My Cupcakes Sink or Overflow?

This is the million-dollar question, isn’t it. Even master bakers are sometimes flummoxed to see cakes they have been expecting to turn out perfectly come out as a perfect disaster. Even a tiny mistake can lead to a cake mess and can make your dessert unsalvageable. I can help you identify the few most common ones that I believe all bakers experience when they are learning how to bake.

Expired Leavening Agent

If your cupcake is not rising properly or has sunk in the middle, one of the most common reasons may be that your leavening agent is not doing an adequate job of lifting it up. This could be because of expired baking soda, baking powder, yeast, or other agents.

When these ingredients are kept too long, they lose their potency over time. When the leavening agent is unable to trigger the chemical reactions necessary for the lift, it will lead to a sunken and sometimes dense cupcake.

The biggest culprit of a leavening agent losing its potency is moisture and exposure to the air, which will weaken it. Therefore , it is important that you store your baking soda in an air-tight jar.

To make sure your leavening agent hasn’t gone bad, pour some vinegar, lemon juice, or other acidic ingredients on a small amount of baking soda. If the mixture immediately starts to bubble and fizz, then your baking soda or baking powder is good enough to use. If the mixture does not react, then you should throw the baking soda/powder out.


Incorrect Amounts of Leavening

Baking soda and baking powder are responsible for making your cupcake rise properly. If you add an incorrect amount to your recipe, it can make your cupcake overflow or not rise at all.

If you add too much baking powder or soda, it can make your batter overflow uncontrollably when hot and then deflate when the cupcake cools down. It also makes your cake taste bitter and unpalatable.

On the other hand, if you have added too little leavening to your recipe, it will not allow your cake to rise properly and it will become flat and dense.

Therefore, it is important to ensure that you always add the correct amount of leavening to your recipe. Beginner bakers should also avoid swapping leavening ingredients with substitutes like swapping baking powder with baking soda, as this can be very tricky and can ruin your entire recipe.

Over Creaming the Butter

Creaming the butter with the sugar is a very important step when it comes to getting the right rise on your cupcakes. If you end up beating your butter and sugar mixture too much, though, you will incorporate too many air bubbles into the batter. When the cake is baking, the air bubbles will release quickly, making your cake rise rapidly and then sinking when it cools.

To prevent over creaming, you should beat your butter and sugar together for approximately two minutes on medium or medium-high speed or until your mixture is light and fluffy. My recommendation is not to go beyond the 2.5 to 3 minute mark ever.

Overbeating the Eggs

Just like overbeating the butter, overbeating your eggs will incorporate way more air bubbles than you need in your mixture. As a result, the cake will inflate quickly when cooking, and then sink in the middle once the air bubbles have all escaped.

To prevent overheating, you should take care to add in the eggs one at a time to make sure one egg has been mixed well with the sugar before you add another. Once you have added the last egg to the mixture, beat it for just a few seconds until it has been incorporated and then stop mixing.

Overmixing the Batter

When learning how to bake, you must have been told time and again to not overmix your batter. The reason is that you do not want your cupcakes to sink.

Now we understand that mixing ingredients helps to incorporate air into the batter. This air is important for helping the cupcakes rise well and deliver the fluffiness, softness, and volume that everyone loves. However, make sure you do not over do this.

Mixing any component of your batter or the entire batter for too long can add in extra air bubbles. This will make your cupcake less likely to rise and make them tough.

To get a beautifully mixed batter, simply stop folding the dry ingredient as soon as the batter becomes lump-free and smooth and looks homogenous. Immediately stop folding after that.


Using Cocoa Powder

When baking cupcakes, you cannot just use any type of cocoa powder you get your hands on. Make sure you understand what kind of cocoa powder the recipe is calling for.

Dutch process cocoa powder (or cocoa powder that has been neutralized) does not react with baking soda and will prevent your cake from rising. This means that you should never use this cocoa powder for cakes and cupcakes recipes that use baking soda.

Typically, it is a good idea to simply use natural cocoa powder, unless your recipe specifically calls for  Dutch process cocoa powder.


Letting the Batter Sit Out

Once all the ingredients have been incorporated in the mixture, you need to set the cake into the oven. If you let the batter sit out, the leavening agents will not be able to give rise to the cake.

The baking powder you use at home reacts with the cake mix by first getting it hydrated and then releasing carbon dioxide when the cake is baking to make it soft and fluffy.

So, the leavening agents will start reacting with your mixture as soon as you put them in the batter, rather than once the batter starts to bake.

This means that if you allow your cake to sit out too long, the reactions will already have happened and your cake will come out deflated, dense, and dry.

This is the reason why you need to bake your cake immediately after the batter has been mixed.

Oven Temperature Too Low

Baking is as science – which means even a single parameter will determine how your cupcake turns out.

One very important parameter in science is temperature. If your oven temperature is set too low, it can spell disaster for your cake. Some bakers turn down their ovens from the standard 350 degree Fahrenheit to 325 degree Fahrenheit if they want flat-topped but perfectly cooked cakes. However, for cupcakes, you want to ensure your oven is set at 350 degrees.

If your oven temperature is too low (lower than 325 degrees), your cupcakes will collapse as it cools. In addition, it can also lead to heavy, dense, brick-like cupcakes which are impossible to bite.

If your cupcakes are simply sunken but cooked through, you can serve them hiding the depression in the center with extra filling, frosting, or fruit. However, if your cupcakes remain uncooked in the center, it might not be possible to salvage them. You can only shave off the pieces from the outer edge and cobble them together to make a dessert and throw out the uncooked center.

Oven Temperature Too High

IF your oven temperature is too high, it will cause the sides of your cupcakes to rise too rapidly. This means that the center part will not have enough time to cook. This will cause the center to collapse inward.

However, if you wait for your cupcake to cook in the middle, the outer edge will become scorched and dry.

To prevent this from happening, make sure your oven is set at the right temperature. Many home ovens are not the best at keeping the correct temperature so it is a good idea to keep an oven thermometer which will give you the correct temperature reading and allow you to adjust the temperature.

To make sure all sides of the cupcake have been cooked, poke a toothpick in the center to see if it comes out clean. If it doesn’t, give the cupcake a few more minutes in the oven under the right temperature.



Underbaking also results in the same type of cake disaster as baking at too low temperatures. If you pull out your cupcakes from the oven before the recommended time, they will not be cooked all the way through, particularly in the middle. This will result in the middle of the cupcakes to sink since it did not have the chance to rise and set properly.

To find out whether the cupcake is baked fully, press the top of the cupcake gently with your finger. If it springs back up, it means the cupcake is done baking. You can also do the toothpaste test to make sure the cupcake is cooked in the middle.

One thing to keep in mind when baking is not to repeatedly open your oven door to check on the cupcake, particularly in the initial 15 minutes. This can fluctuate the temperature in the oven and make your cake bake unevenly or sink.

Not Following the Recipe

For beginner bakers, it is important to follow the recipe to the T rather than try experimenting. Expert bakers can experiment with their cupcakes since they have an in-depth understanding of how every ingredient will react and what outcome every step in the procedure will produce.

If you add too many wet ingredients and too little dry ingredients, your cake will not rise enough. Adding more ingredients into your recipe later on at the incorrect stage or using substitute ingredients can also lead to your cupcakes sinking or overflowing. If you are adding more ingredients to your recipe, you will also need to adjust the amount of the leavening agent properly so that your cupcakes rise perfectly.

Do not try to improvise too much as it can lead to unpredictable results and waste expensive ingredients.

Overfilled Cupcake Liners

The most obvious reason for overflowing cupcakes is that you have filled your cupcake liners to the tops. Many people do this hoping to get giant-sized cupcakes.

It is true that if you add more batter to the cupcake tin, they will produce bigger cupcakes – however, this logic is only true to an extent. Don’t forget that your cupcakes will expand as they bake and if you have filled the liners to the top, they will either overflow from the side or will become misshapen and lumpy. Plus, when the cupcake cools down, the batter may have a sunken look.

To make sure this doesn't happen, only fill your cupcake liner no more than two-thirds of the way, leaving sufficient space for your cupcake to rise. There are some recipes that call for filling your cupcake liner only halfway and you should always heed those.

How Do You Prevent Your Cupcakes From Sinking

You can avoid a sunken cupcake by paying attention to the tips above – by making sure you follow the recipe, making sure your leavening agents are effective, your batter is perfectly mixed, and your oven temperature is set correctly.

To get the best results, make sure to bake only a single tray of cupcakes at a time in the oven. If you force two trays at the same time, the cupcakes will not get the right amount of airflow and heat and will not rise well.

If you think you are saving time by putting in two cupcake trays, think again. Baking more than one cupcake tray will increase your bake time by 15%, which will ensure that the temperature reaches the top and the bottom of your batter evenly. You might also have to rotate the trays or switch their places to ensure even baking. For beginner bakers, I advise that you master baking a single pan of cupcakes first before you get down to baking multiple trays in the oven simultaneously.

How Do You Prevent Your Cupcake From Doming?

Overmixing cupcakes can cause them to become domed and even flatten out once they cool. When you overmix, you will add too many air bubbles into the batter which will cause the mixture to rise too early and by far too much. Instead of becoming deflated, some cupcakes will overflow and make a dome.

Leaving your batter to sit out on the counter will also cause the baking powder or baking soda to react while the mixture is still in the bowl. This can also cause your cupcakes to dome in the oven.

The wrong temperature in the oven can also cause your cupcakes to rise over much.


How Do You Salvage Sunken Cupcakes?

If your cupcakes appear to be sunken, do not give up hope and take them out of the oven. Keep baking until they are baked all the way through as you may still be able to eat them. Do the toothpick test and if the toothpick comes out clean, your cupcakes are ready to come out of the oven.

Although they may have sunk and may not look as perfect, they may still taste good. If the center is not too depressed, you can easily disguise it by piling on the frosting, fruit, and candy on top of it. Once you eat the cake, you won’t even notice the sunken center.

If your cupcakes have sunk in too much and piling on frosting may still not be able to hide your error, you can still use them. Just let them cool off, peel off the liner, and then break the cupcake into chunks. You can then make a separate deconstructed dessert out of them by layering the cake chunks with fresh cream, custard, and fruit.

How Do You Salvage Overflowing Cupcakes?

Although you cannot fix overflow cupcakes while they are in the oven, you can still save them once you have them out. Make sure you cool your cupcakes for at least 10 minutes before removing them from the rack. Allow the cupcakes to completely cool for about an hour.

Cover the cupcakes with lots of frosting to hide the imperfections and the distorted shape. If you do not feel comfortable doing this, you may try to shave off the excess part and then coat the cupcakes with icing. They should still be good to eat.

If you are very unlucky, then your sunken or overflown cupcake will have bigger problems than just the shape. A lot of time, beginner bakers also experience cakes that are ridiculously dry, dense, scorched, or bitter in taste. If any of these things have happened to your cupcake, it is best to shave off any edible parts that you can and throw away the rest.

It is a sad waste but eating such cupcakes can only lead to a stomach ache, so it is best to be rid of them and learn from the experience.


Lori Gilmore

Lori Gilmore

Lori has been a Culinary Arts instructor for twenty years. She has taught in the public school setting, at the collegiate level and through adult continuing education as well as running several cooking and baking camps for children. She has participated in several cooking, cake & chocolate contests and has been well recognized. She has raised thousands of dollars for charities using the byline “Saving the World one Cupcake at a Time”. Additionally, she has had several articles regarding food published in various magazines.

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