Why Do Cakes Sink?

We’ve got the answer to a big question that’s crossed all of our minds: why did my cake sink?

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We like to make sure that all Cake Decoration & Sugarcraft platforms are safe spaces to share all of your baking woes, so don’t worry, we’re not ashamed to admit that we’ve had a sunken cake disaster (or a few) in our time! Instead of throwing our spatulas out of the drawer, we realised it would be far more productive to find out exactly why cakes sink!

So if you’ve ever sat in despair in front of a sad, biscuit-like excuse for a cake, we’ve got a fabulous list of solutions on why cakes sink in the middle, around the edges and all over! 

Why Do Cakes Sink?


Temperature is incredibly important when it comes to preventing a cake sinking disaster. No matter how brand-spanking new, top of the range, Mercedes-of-the-appliance-world level your oven is, it will have its quirks. Ovens are just like that! They have hot and cold spots, which may not be too significant on your thermometer, but can have devastating consequences to your cakes. Test your oven before baking, checking areas with a thermometer at different angles to find the optimal areas of even temperature inside the oven. If you leave the cake to cook in a spot that is cooler than the recommended temperature, it can take too long to cook, meaning the raising agent you use will stop working. As the carbon dioxide bubbles will only last so long, so if the cake has cooked too slowly and hasn’t set before those bubbles run out, you will be left with a sunken cake. 

Top Tip! This is another reason why preheating the oven is always an instruction when baking. If the oven is still getting to temperature while the cake is inside, the cake won’t set before the raising agent runs its course and your cake will sink in the middle.

Cake temperature


Keep It Closed

“Don’t make me close… one more door… unless it’s the oven door, then please close it and keep it closed!” Now we’ve got a wonderful Whitney tune stuck in your head, it’s time to talk about keeping the oven door closed. If your oven has a nice window and a lovely little light built in, use them! Opening the oven door too early will let a blast of cold air into the oven, causing a devastating weather disruption and storm inside your oven, lightning, thunder, hail etc… We’re exaggerating of course, however the change in temperature before the cake has set will almost always cause your cake to sink in the middle. 

Top Tip! If you are baking something that needs to be turned in the oven, wait for around ¾ of the baking time before rotating, to give the cake the best opportunity to set before changing the temperature inside the oven. 

It’s also really important to be gentle with the door when opening and closing it too. A sharp closure can cause a drastic change in temperature and potentially upset the delicate aeration you will have stirred into the cake. So, be patient and if you have to open the door, be very careful!

Open oven door


Baking Powder

Baking powder can significantly change the amount of rise your cake achieves. As you will have (hopefully!) read in our blog post on Baking Science: How Does Baking Powder Work? baking powder is an essential element to help your cake rise. If you’re wondering why did my cake sink? then the culprit may just be a tiny, innocent-looking spoonful of powder. First things first, check the date on your baking powder! While it won’t go immediately mouldy or funny-tasting when out of date, the chemical reaction to create bubbles that help the cake rise will be far less effective. Less bubbles means less time to help the cake rise before it sets, resulting in a sad sunken cake! 

Measure your baking powder (in fact, all of your ingredients!) carefully. Not enough baking powder, the cake will not have adequate time to rise and set and it will sink. Too much baking powder has a double effect of making the cake taste bitter and nasty, as well as causing the batter to rise too quickly and then sink. Too much baking powder means the carbon dioxide reaction goes into overdrive, creating too many bubbles too quickly. The reaction then runs its course too quickly, hence the rapid rise and subsequent fall of the cake. 

Baking Powder


Batter Awareness

How your create your cake batter can also hugely contribute to why cakes sink. Overmixing your cake mix will result in the bubbles being stirred out of the mixture and the gluten in the flour will form elastic strands. This will leave you with a more dense and chewy textured cake. While it won’t cause a distinctive sinkhole in the middle of the cake, the cake will struggle to rise and stay risen, resulting in an all-around sinking that makes it so dense. 

It’s also really important not to leave your uncooked cake mixture sitting around for a long time (or any time!) before putting it into the oven.This is again to do with getting the best reaction from your raising agent and giving it the longest amount of time possible to work its magic. So once you have added your raising agent, get that mix into the oven as quickly as possible! 


Mixing cake batter



Fixing A Sunken Cake

Now, if you do end up with a sunken cake, have no fear - it is fixable! Instead of dejectedly staring at your sad sunken bake, bemoaning ‘why oh why did my cake sink in the middle?’ and preparing to either dramatically throw it in the bin or eat the whole thing yourself in protest, follow our top tips for rescuing a sunken cake! 


A Minor Cake Sink
Use your imagination and change up your decoration design a little! If there’s only a small depression, it just needs a smidgen of evening out. What’s important to note here is with a small sinkage your cake should still be fully cooked, so it’s safe to eat, just a little squashed! Simply add some form of filling, like buttercream, cream cheese, even a bit of jam! Just use enough to make the top even and you can cover the cake afterwards with sugarpaste meringue or buttercream, hiding all evidence!


Cake covered with meringue


A Major Cake Sink
If your cake has sunk in the middle and has a crater worthy of being smashed by an extinction-level meteor, you’ve got a little more repair work on your hands. However, it’s not the end of the world! You will first need to entirely remove the centre of the cake. The rest of the cake will be cooked and can stay, however the sunken bit will unfortunately still be mostly raw so it’s got to go! Use a large cookie cutter or chef’s ring to take out the centre, or simply scoop out the uncooked section with a spoon. Then get filling! Use whatever your like, such as frosting, fruit, icing or cream cheese. Once you have reached the top of the cake and have a lovely even top, cover it up and no one will ever know! 


very decorated cake


More Methods
As you may have guessed, filling a gigantic sinkhole with lots of icing may not create the right taste for your cake. If you’d rather not cover the hole and want to be even more creative, you could always turn the cooked parts of the cake into cake pops, or make a lovely trifle! Or, simply decorate the edges of the  inner hole and make a stylish cake ring instead! 


dDecorated cake ring


So now you know the answers to the dreaded question: why did my cake sink? It always helps to know why cakes sink, so you can learn how to stop it happening in the future! Whether you are wondering why do cakes sink in the middle or why is my cake so flat, you can check through our handy guide and make sure you bake the most unsinkable cake possible! 

If you’re looking for more handy hints like this, check out our blog post on How To Moisten A Dry Cake if you’re having any more baking dilemmas! 

For great tutorials, fabulous sugarcraft and cake decorating galore, pick up the latest issue of Cake Decoration & Sugarcraft magazine today! 

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