Why is My Buttercream Runny?

I’ll be honest – I have a pretty strong sweet tooth, and it’s hard for me to say “No” to desserts. It gets trickier when a dessert, such as a cake or a cupcake, is slathered with buttercream frosting. It’s my absolute favorite, as the taste is rich and the texture is creamy.

But that’s just the thing – buttercream is supposed to be creamy and smooth. So what if you’re left with a bowl of buttercream “soup?” What went wrong here?

Many things can cause the buttercream to be runny, from a too-hot kitchen to too much liquid. The good news is that runny buttercream can easily be fixed – and that’s exactly what we’re discussing today.

Let’s fix that runny buttercream!

Why is My Buttercream Runny? 5 Reasons

Nobody wants to drizzle runny buttercream over their freshly-baked treat. And if you keep getting stuck with a soupy mess, it’s essential to know what’s causing it.

Here are the top five reasons you’re getting runny, messy, and undesirable results.

1. Too Much Liquid

The main culprit of runny buttercream is too much liquid (especially milk).

That’s why it is imperative to follow your recipe closely. If it calls for two tablespoons of milk, use two tablespoons and not an inkling more. If you need to use 1 ½ teaspoon of pure vanilla extract, then do just that.

That said, you should make sure you have some high-quality measuring spoons and measuring cups on-hand at all times. “Eye-balling” your ingredients will lead to disaster, especially when it comes to the somewhat finicky buttercream. 

2. Too-Hot Kitchen

To be honest, I can’t imagine this ever happening. I can’t stand baking in a kitchen that is too hot, and I would assume that you don’t, either. But I get it – things happen. Maybe your air conditioner is broken, or it’s just an extra humid day. 

You need to be mindful of your kitchen’s temperature and humidity levels, though. Since buttercream frosting is made of mostly butter (and sugar), it can quickly melt at undesirable temperatures.

3. Overbeating

Beating is a critical part of creating buttercream and should be done by an electric mixer (either handheld or countertop stand mixer). However, overbeating is a crucial cause of buttercream becoming a runny mess. 

4. Warm Ingredients

Remember – heat and humidity are big no-nos for buttercream. But that doesn’t just reflect the kitchen temperature. You must also pay attention to the temperature of your ingredients, as warm components will be more prone to runniness.

Buttercream Too Runny? Here’s How to Fix It

Runny buttercream just won’t work. But wait! Before you toss out that fresh batch of soupy buttercream, you should know that there are easy ways to “bring it back to life.” Check it out!

1. Add More Powdered Sugar

The simplest way to fix runny buttercream is to add more powdered sugar and mix, one tablespoon at a time until it’s reached the desired consistency.

Powdered sugar works wonders because it can act as a thickening agent yet has a delightfully sugary taste that won’t overpower the flavor of your frosting. 

If you don’t have any more powdered sugar on hand, you can also opt for cornstarch. But you need to be careful with cornstarch. Too much will cause an unpleasant starchy taste that may ruin your buttercream.

2. Chill it in the Refrigerator

Another quick trick is to stash it in the fridge for around 10 to 15 minutes. Some or all of the buttercream should thicken in the chilly environment. 

Sometimes, chilling in the fridge will cause the outer portion of the buttercream to stiffen while the inner section stays runny. That’s okay! Scrape off the thickened sides and use it as normal. 

You can also try mixing the runny and thickened parts together as long as there isn’t too much liquid.

How to Avoid Runny Buttercream

Now that you know how to properly fix your runny buttercream, it’s time to discuss how to avoid it in the first place. After all, prevention is always better than a cure. 

1. Measure Ingredients

Following a recipe instruction by instruction is vital for buttercream success. 

Make sure you’re measuring out all of the ingredients, liquid ones especially, and add them when called for. 

But don’t forget the importance of adding the right amount of butter, either. Butter is a solid fat that produces the desired thickness of the frosting. So, while you can get it by adding a pinch more butter, it’s best to be precise with the measurements.

2. Cool Down Your Kitchen

Heat and humidity are two big enemies of buttercream. And let’s face it – you deserve to be baking in a pleasant and cool kitchen, anyway.

Do yourself and your buttercream a favor and turn on the air conditioner. If nothing else, at least use a couple of fans pointed into the kitchen to help it cool down.

3. Don’t Overmix

You will want to beat the buttercream until soft peaks begin to form and thickens, typically 3-5 minutes on medium-high or high power (follow the instructions of the recipe you’re using). Once you see the peaks and thickness, stop beating immediately.

Overbeating will cause the buttercream to “deflate” and become runny, and the heat from the mixer can also contribute to soupy buttercream. Be peculiar about how long you’re beating your buttercream for better success. 

4. Use Cold Ingredients

I would never suggest using warm or even room-temperature ingredients, especially when it comes to the butter and liquid element. Make sure these ingredients are chilled in the fridge before whipping together your buttercream, and it should create the preferred texture.


Runny buttercream is a messy situation – literally – but that doesn’t mean it can’t be fixed with the proper steps. If you want to learn more about why your buttercream is runny and some other fantastic info, check out these FAQs.

How can I thicken buttercream without powdered sugar?

The second best option is to stash it in the fridge for 10 to 15 minutes. If you don’t want to wait that long, the third choice is to add shortening and flour to the frosting. The shortening will add much-needed thickness, and the flour will create the right consistency.

Can you over-mix buttercream?

You can overmix buttercream, which will essentially cause it to deflate and become runny. Following the recipe, step-by-step is the best way to ensure that this does not happen. And, always make sure to stop mixing once you see stiff peaks and thickness.

How do I fix runny cream cheese frosting?

Runny cream cheese frosting can be saved the same way buttercream frosting is. The best solution is to add some powdered sugar or cornstarch. You can also refrigerate it to stiffen it up. Some have also used icing sugar, meringue powder, and arrowroot powder successfully.

Final Words

Your buttercream is likely runny because you added too much liquid. However, the temperature of your kitchen and/or the ingredients you’re using may also be the culprit. Last but not least, overbeating can cause deflation and runniness. The good news is, whatever causes your soupy buttercream, you can simply add powdered sugar or chill it to improve the consistency.

Have you ever dealt with runny buttercream? How did you fix it? Comment below!

About Michelle
I have been a lover of sweets since day one. This led me on a self-taught baking journey starting at the age of 13. It's been over 10 years since the start of my baking adventures, and I’ve learned a lot along the way. Now, people rave about my delectable treats, whether it’s a chocolate cake or a strawberry crepe.

Leave a Reply

Your email address will not be published. Required fields are marked *