How To Thicken Frosting in 5 Simple Ways – From Runny to Fluffy

Find out how to Thicken Frosting fro cake and cupcakes

I am up for baking cupcakes for my daughter’s birthday. I have made frosting for some birthday cakes before, but this time I want it to be a bit fancier. My little one loves cupcakes with swirling colorful frosting on top. Hence, I need to make a denser frosting to make it easy for me to think of a design.

Do you know how to thicken frosting? I have five simple ways to do it and solve the problem of runny or soggy frosting. I bet you are now thinking about how to make cupcakes fun for the kids, and the kids at heart!

5 Simple Ways to Thicken Frosting

You do not need to be an expert in decorating cupcakes to do the frosting. How was your first try of making these sweet and yummy delights? Mine was a little soggy at first, but as I learned the tricks on how to make it firm, there is no limit on what I would like to create.

As soon as I have managed to perfect my consistency, making it is indeed a piece of cake!

1. Thicken your frosting with cornstarch

As my kids would say, “Cupcakes aren’t real without frosting!” Therefore, I tried hard to come up with a smooth, thick, and spreadable kind of icing. Do you know that powdered sugar already has cornstarch with it? When the end result is too thin, you can thicken it with the use of additional cornstarch.

What you will need:

  • Cornstarch
  • Electric Grinder
  • Teaspoon
  • Whisk or Mixer

What to do?

  • Pour 2 teaspoons of cornstarch into your electric grinder and pulse to grind until it appears like soft powder.
  • When it is ready, scoop a ½ teaspoon of the cornstarch to your runny icing, before whisking it. Using an electric mixer is convenient too.
  • While mixing, you can add ½ teaspoon gradually until all the cornstarch dissolves.

Two teaspoons of cornstarch is a good start. As long as you mix it gradually to your frosting, it will be fine. However, the amount of cornstarch will depend on how much frosting you made. If you made plenty, two spoons of cornstarch might not be enough.

Make sure to add cornstarch slowly, ½ tsp. at a time, until you reach the icing consistency, you desire.

2. Thicken your frosting with sugar

frosting with sugar

A cake with a runny frosting is never appealing. In fact, it is lifeless. Cake decorators can suggest different ways to fix it. Adding sugar to thicken a naughty frosting is one of them. I usually do this either with a mixer or just a bowl and spatula.

What you will need:

  • Sugar
  • Bowl
  • Electronic Mixer
  • Spatula

What to do?

  • Using a mixer is the quickest way to fix a soggy frosting. Just put all of it inside the mixer and add in the sugar. I suggest adding it in gradually, pulsing the mixer every after each addition. Do the same step until it reaches the consistency you need. This method is suitable when you are in a hurry, and you have made a huge batch of soggy frosting.
  • Since I started using it for our daily cake cravings, I only make a batch good enough for the day’s consumption. Hence, a bowl and spatula are practical. Just put it inside the bowl and add the sugar bit by bit while mixing it well using the spatula. Do the same until you observe the icing beginning to look firm.

3. Thicken your frosting with heavy cream

Cream Frosting

Since frosting is already sweet, adding sugar may be effective to thicken the frosting. For the health conscious who controls sugar intake for kids, and for those that are at risk of high sugar level, they should look for other alternatives. Therefore, I suggest using heavy whipping cream instead.

What you will need:

  • Heavy cream
  • Measuring spoon
  • Mixer
  • Whisk

What to do?

  • Pour your frosting inside a mixer.
  • Add 4 tablespoons of heavy cream and whip it until it appears thick and frothy. If needed, you may add the heavy cream one tbsp. at a time for easier monitoring of consistency.

Using a whisk is much easier for me though (for a small amount of icing), and I believe that it is more effective considering that I can closely monitor the consistency than using a mixer. Just beat by hand, until it is thicker than before. Do you know that the heavy whipping cream will not only thicken it but also makes it lighter, softer, and fluffier?

4. Thicken your frosting with gelatin

Thicken Your Frosting With Gelatin

Do you know that gelatin is a thickening agent? You can find it inside marshmallows and jelly sweets you buy at the stores. They are usually in packs with different flavors and may come instant or needs boiling. I suggest using the clear (or plain) gelatin so that it will not affect the color of your frosting.

If you have not tried making gelatins, here is a video showing you how.

What you will need:

  • Newly mixed gelatin (make sure it hasn’t set yet) still in a liquid state

What to do?

  • After making the gelatin (as the video shows), pour it into the frosting that you made. Stir it well until both are thoroughly mixed.
  • Chill the frosting into the fridge to thicken.

Using instant gelatin (the type that only needs cold water) is a lot easier. You can mix a small amount with cold water bit by bit, and gradually mix it with the frosting. This way, you can see the change of the consistency closely. I advise doing this quick before the rest of your gelatin solidify.

5. Thicken it with shredded coconut

Coconut Cake

Take note that this method is only applicable if your frosting is coconut flavor. Otherwise, the coconut taste and aroma will conflict with your existing flavor.

What you will need:

  • A pack of shredded coconut

What to do?

  • Just add a tablespoon of shredded coconut to your bowl of frosting, gradually. Make sure to mix well every after addition. Do this until it thickens.

Here is a video about how to make cooked flour frosting:

Different Variants

You have learned different ways on how to thicken the frosting. At least, next time you make it runny, there is no need to worry. It’s fine to be thin when all you have to do is glazing.

Nevertheless, cakes and cupcakes are more tempting when looking colorful and fancy. That is why thickness is necessary. Therefore, the consistency depends on the type you mean to make. The weather and the ingredients are the common reasons why frosting comes out runny.

Here are the different types of frosting that you may make for every occasion.

  • Cream Cheese: The method of adding sugar to thicken is applicable. You may have over-softened your cream cheese resulting in it being
  • Whipped Cream: Adding cornstarch to thicken it would work. Ensure to chill the whipping cream before you whip it.
  • American Buttercream: The usual cause of a runny American buttercream is too much milk. Add sugar to thicken it.
  • Royal Icing: Do you find your royal icing too thin? The trick is to add sugar to make it thick. You may want to add more meringue powder if you do not like the icingto become very sweet.

Some points to remember:

  • The newly made icingis usually runny especially if it is still a bit hot. Give it time to set. When after some time it is still the same, then you can start finding a way to thicken it.
  • Butter base and whip cream, it will become runny if exposed to heat. It is advisable to keep it in the fridge.
  • Wait for the cornstarch to cool down before mixing it to the frosting. Otherwise, it will melt the butter and make your problem worse.
  • The trick there is to add gradually the ingredient to reach the consistency you need for your icing.


What do I do if my frosting is too runny?

If your frosting is too runny, there are several ways to thicken it without using powdered sugar:

  • Chill: Place the runny frosting in the refrigerator for 15-30 minutes, checking and stirring it occasionally. The cold temperature will help it to firm up. Be cautious not to leave it in the fridge for too long, as it may become too stiff.
  • Add cornstarch: Cornstarch can help thicken without altering the flavor too much. Start by adding 1 teaspoon of cornstarch per cup of icing, and mix well. If needed, add more cornstarch in small increments until the desired consistency is reached.
  • Use cream cheese: Adding cream cheese can help thicken it while also adding a rich, creamy flavor. Start by adding 2-3 tablespoons of softened cream cheese per cup of frosting and mix well. Adjust the amount of cream cheese as needed to achieve the desired thickness.
  • Add more butter or shortening: If it is buttercream-based, adding more butter or shortening can help thicken it. Make sure the additional butter or shortening is at room temperature and mix it into the frosting a tablespoon at a time until the desired consistency is achieved.

Can I use instant pudding mix to thicken frosting?

Yes, you can use instant pudding mix to thicken your frosting. Choose a flavor that complements it and mix in a small amount, starting with a tablespoon per cup. Mix well and add more if needed, until the desired consistency is reached. This method not only thickens the icing but also adds flavor.

Can I use cocoa powder to thicken chocolate frosting?

Yes, you can use unsweetened cocoa powder to thicken chocolate frosting. Start by adding a tablespoon of cocoa powder per cup, and mix well. Add more cocoa powder in small increments until you achieve the desired consistency. Keep in mind that adding cocoa powder will intensify the chocolate flavor.

How can I prevent my frosting from becoming runny in the first place?

To prevent your frosting from becoming runny, follow these tips:

  • Measure ingredients accurately to ensure the correct ratio of liquid to dry ingredients.
  • Use room temperature butter for buttercream, as melted butter can cause a runny consistency.
  • Avoid overmixing, as this can introduce too much air and cause it to become thin.
  • When using cream cheese, make sure it’s not over-softened or melted, as this can lead to a runny frosting.

How long does it take for it to set?

How Long Does It Take For Frosting To Set

The time it takes for frosting to set depends on the type of frosting and the environmental conditions. Generally, buttercream and cream cheese frostings set in about 30 minutes to 1 hour at room temperature.

Royal icing may take longer, anywhere from 1-3 hours, or even overnight for thicker applications. If you’re in a hurry, you can speed up the process by placing the frosted item in the refrigerator for 15-30 minutes.

Can I freeze it to thicken it?

Freezing is not recommended for thickening, as it can cause the frosting to become too stiff and difficult to spread. Additionally, the texture and consistency may change when the frosting thaws. It’s best to use one of the methods mentioned earlier in the text to thicken your frosting without affecting its quality.

Can I use flour to thicken frosting?

Flour can be used to thicken frosting, but it is not recommended, as it can give the icing a gritty texture and a raw flour taste. If you decide to use flour, make sure to cook it first by making a roux with equal parts flour and butter, cooking it until the raw flour taste is gone, and then cooling it completely before incorporating it.

My Final Thoughts

After experimenting with various methods to thicken frosting, I’ve come to realize that achieving the perfect consistency is both an art and a science. From incorporating powdered sugar to chilling the mixture, each technique has its unique impact on the texture and flavor.

While some methods are quick fixes, others require a bit more patience. It’s essential to understand the type of frosting you’re working with and the desired outcome you’re aiming for. In my journey, I’ve discovered that sometimes the simplest tweaks can make a world of difference.

So, the next time your frosting feels a bit runny or thin, remember these five techniques. With a little practice and patience, you’ll master the art of perfect frosting in no time!

Picture of Mary J. Lynch

Mary J. Lynch

As a mom of two angels, I credit myself in making meals with high concentration yet the balance of nutrition. I pay good care about the health of my family and everyone. Thus, you will find most of my recipes focus on healthy ingredients.
Related Posts