Fixing Lumpy Buttercream Frosting

Nothing ruins a beautifully baked cake like lumpy buttercream frosting.  For many cakes, the buttercream frosting is the main treat that brings finesse to the cake. 

It can be frustrating when your buttercream doesn’t turn out the way that you want it to.  In fact, you can be left wondering where you went wrong and how to fix it. 

In this article, we will look at what causes broken buttercream, and how to fix lumpy buttercream frosting. 

What Causes Lumpy Buttercream Frosting?

The first thing we need to look at is what causes lumpy buttercream frosting.  As a general rule, there are two main reasons why your buttercream might end up being lumpy. 

Either you are using butter that is too cold to make your frosting, or you haven’t properly sifted your powdered sugar. 

Both of these things can lead to curdled buttercream. 

What Causes Broken Buttercream?

Broken buttercream is another way in which buttercream frosting can turn out wrong. 

The main causes of broken buttercream are using butter that is too hot, which can cause the dreaded buttercream split and look greasy because of too much liquid, the butter can also be too cold which can cause curdling. 

To fix broken buttercream you need to make sure that you are using butter that is the correct temperature. 

How To Fix Lumpy Buttercream Frosting

The first thing that you will do if your buttercream ends up being lumpy is to panic, especially if you are working to a time limit. 

However, with these tips, you can skip that step and get straight to an easy fix.  Below, we will detail the three main fixes to save your buttercream. 

Fixing Lumpy Buttercream Frosting

Heat It

One of the most common ways you can fix lumpy buttercream frosting is to heat it slightly.  One main cause of lumpy buttercream is using butter that is too cold. 

When the butter is too cold, it is more difficult for it to combine properly with the icing sugar in the frosting. 

If cold butter is the cause of your lumpy icing, you can remedy the problem by warming the buttercream slightly.  

Place the lumpy buttercream in a microwave-safe bowl and gently heat the mixture for around 20-seconds.  The defrost setting on your microwave should be enough to soften the butter. 

Once you have heated the buttercream slightly, stir the frosting to remove the lumps and help the ingredients incorporate. 

If there are still some lumps, you can heat the buttercream again for 10-20 seconds and stir again.  

The heating method can also be used for lumps caused by unsifted powdered sugar.  The heat helps the unsifted sugar incorporate more easily into the butter. 

Beat It

While it is important to not overbeat your buttercream as this can cause splitting, sometimes beating the buttercream can help remove the lumps. 

Sometimes lumps can be the result of the mixture not being mixed for long enough for the ingredients to properly combine.  

Removing lumps that are caused by a lack of mixing is more easily done with a stand mixer than a hand mixer.  Put the frosting in a mixing bowl and set the mixer on medium to high speed. 

Leave the mixer running until any small clumps that were in the icing have disappeared, this should take about 2 minutes.  

Add More Liquid

If your buttercream icing is lumpy because the mixture is too dry, you can add more liquid.  You shouldn’t add more buttercream as this can change the volume of buttercream that you make. 

Instead, you can add liquid, such as water or milk, one tablespoon at a time until the frosting is smooth.  Sugar syrup can also be used. Add the liquid while mixing the frosting at a low speed.

Make sure to allow the liquid time to properly absorb before adding more to prevent runny frosting. 

How To Prevent Lumpy Buttercream Icing

Fixing Lumpy Buttercream Frosting

You will have heard the saying, prevention is better than cure, which also applies to lumpy frosting. 

While it is great to be able to fix buttercream that comes out lumpy, it is better to prevent it from happening in the first place. 

There are two main ways in which you can prevent lumps in your buttercream and get smooth results.  

Use Softened Butter

When butter is cold, it doesn’t like to mix with other substances smoothly. 

To make sure that your butter is primed to be mixed into a velvety smooth buttercream, you should allow it to get to room temperature before using it in your frosting. 

If you normally keep your butter in your refrigerator, it is best to leave it out overnight or at least for 6 hours.  

If you are on a time limit and don’t have time to leave your butter out for hours to reach room temperature, you can cheat a bit. 

Place a microwave-safe bowl in the microwave and heat it for 20 seconds.  Once the bowl is warm, remove it from the microwave and place it upside down over the butter. 

This trick can bring your butter to room temperature in as little as 10 minutes.  

Sift Your Powdered Sugar

Another way to prevent lumpy icing is to sift your powdered sugar before mixing it with the butter. 

When you add powdered sugar to the fat to create buttercream without sifting it, all the clumps of sugar are mixed into the frosting. 

As a result, you will end up with frosting that has pockets of powdered sugar in it.  No one wants to bite into a cake and end up with a mouth full of powdered sugar.  

To successfully remove the lumps that form in icing sugar or confectioners sugar, measure out the amount that you need for your icing. 

Then transfer the sugar to a sieve above your mixing bowl.  Gently tap the side of the sieve to encourage it to fall through the holes into your stand mixer bowl. 

You are likely to end up with some icing sugar on your work surface unless you are a trained chef, but that is the nature of confectioners sugar. 

Sifted powdered sugar will help you create soft, delicious icing.

Final Thoughts

Lumps in buttercream can be a common problem for many bakers, however, there are some easy fixes to help you avoid the issue. 

Thankfully, plenty of recipes will also include these tips to make sure you don’t forget them.

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Kathryn Sewell

Hi! I'm Kate and I have been baking and cooking for as long as I can remember. I like to share the most interesting tips and recipes I try here on What Kate Baked for you to enjoy. If you have a favorite recipe you'd like to share send it over on social.

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