Why Did My Cake Sink?

Have you ever baked a cake only to have it sink in the middle when you pulled it out of the oven? Here are 7 common reasons why cakes sink.

It can feel like you’ve done everything right and then you take your beautiful cake out of the oven and it’s either sunken in the middle or it sinks as it cools.

Sometimes it still tastes fine and it’s more the look of the cake that’s upsetting. Other times it’s wet and underbaked in the middle, ruining the entire thing.

After coming across this problem in my own kitchen, I’ve done some research to find out the main reasons why cakes sink – so we can avoid sunken cakes in the future.

Here are 7 common reasons why cakes sink in the middle.

1 Your cake was underbaked

Almost 100% of the time in my own kitchen, the reason my cakes have sunk in the middle is because they weren’t fully cooked. 

Sometimes your cake might look cooked but after removing it from the oven and setting it aside to cool, it slowly sinks into a crater-like shape. 

In this case, you’ll usually find it’s moist, wet, doughy or in some cases, completely raw in the middle. This simply means it hadn’t finished cooking. Keep in mind, a cake will cook from the outside in, so the centre will be the last place to cook through.

Always make sure your cake is fully cooked before removing it from the oven. 

You can check for visual cues, such as an even browning on top, if the edges start to pull away from the pan and if it no longer wobbles in the middle. But the easiest way to check your cake is completely cooked is by inserting a skewer into the middle of the cake and seeing if it comes out clean. 

Every oven is different, so if a recipe states that your cake will be cooked in 40 minutes, don’t just take it out at the 40 minute mark. Check if it’s done first. Your cake might need longer and this is completely fine.

Cooking times can vary on the type of oven and settings used, the type and material of the cake pan, the ingredients, the placement of your cake in the oven – the list goes on. 

I always recommend using cooking times as a guide only.

Get to know your own cookware and oven and you’ll soon be able to better judge cooking times.

I also highly recommend investing in an oven thermometer.

It will tell you the exact temperature of your oven as the dial isn’t always accurate. It’s also a great way to know when your oven is correctly preheated. 

Your cakes may be underbaked because you are placing them in the oven before your oven has heated to the correct temperature.

2 You opened the oven door too early

While it’s important to check your cake is ready before removing it from the oven, you must make sure you don’t open the oven door too early. If you open the door before the cake is set, the shock of cold air may cause your cake to instantly sink. 

Try to ensure your cake is at least three-quarters of the way through baking before you consider opening the oven door to take a peep.

Likewise, if you shut the oven door too harshly, the sudden movement can also cause a fragile or not fully cooked cake to sink. Be gentle! 

3 Your raising agent has expired

If you don’t bake super regularly, you might find that your baking powder or baking soda has expired. These ingredients are extremely important in creating a cake that rises – and stays risen – so double check they aren’t past their use by date. 

I recommend buying new baking powder and baking soda at least every 6 months to avoid this problem. And make sure you store them tightly sealed at room temperature.

4 You over-mixed your cake batter

Many cake batters call for a light hand when mixing. Over-mixing may result in accidently incorporating too much air into your cake batter which will cause it to rise and then promptly sink when cooling. 

5 You let your cake batter sit before baking

We know that baking a cake is essentially a chemical reaction. Raising agents like baking powder and baking soda can start working as soon as you create your cake batter, and if you don’t bake it straight away, they may not work as intended.

It’s important to preheat your oven to the correct temperature before your cake batter is ready.

Once you pour your batter into your cake pan, place it straight in the oven (unless the recipe specifies otherwise). 

6 You incorrectly measured your ingredients

Make sure you carefully measure out ALL your ingredients when baking. 

I recommend using a baking scale as cup measurements can be wildly inaccurate, especially when measuring dry ingredients like flour.

When measuring out your raising agent/s, take care to use exactly what the recipe specifies. Unless otherwise stated, teaspoon measurements should be level – and not heaped.

If you accidentally add too much baking powder or baking soda, your cake will quickly rise and then promptly sink since the structure of the cake won’t be able to support itself. 

Also, don’t mix up the two. Baking soda is around three to four times more powerful than baking powder.

7 The ratio of ingredients is off

If you are certain you didn’t do any of the above, you may find your recipe doesn’t offer the correct ratio of ingredients. It may offer too much moisture (wet ingredients) and not enough dry ingredients (for structure) or too much raising agent. 

If you’re making a crumb cake, sometimes the crumb can be too heavy for the cake. There might be too many crumbs or the cake underneath is too light and tender to stand the weight.

Or you may have forgotten an ingredient (it happens to the best of us) or measured an ingredient incorrectly. 

how to stop your cake from sinking

1. Make sure your oven is correctly preheated
2. Check your raising agents are fresh and stored correctly
3. Take care when measuring all your ingredients
4. Don’t open the oven door too early
5. Always gently open and shut your oven door
6. Double check your cake is fully cooked before removing it from the oven

more baking tips

• Why Are My Cookies Flat?
• What Is Caster Sugar?
• Why Didn’t My Cookies Spread?
• How To Make Swiss Meringue Buttercream