How To Thicken Buttercream Frosting

Buttercream frosting is a delicious treat that adds flavor and richness to cakes.

However, it can get runny after being left out in a warm kitchen for too long. This makes it difficult to pipe or spread onto cake layers.

So, how can you thicken buttercream frosting?

In this article, we will provide you with a step-by-step guide on how to thicken frosting and achieve the right consistency when making buttercream. 

Let’s get started.

Buttercream frosting can be too thin for a variety of reasons, such as adding too much milk, too much liquid, or leaving it out in a hot kitchen.

Thickening frosting is easy once you know how, and can be achieved with different thickening agents.

How To Thicken Buttercream Frosting

To thicken frosting, all you will need is:

• 1/2 cup powdered sugar

• 2 tablespoons corn starch

• 3 cups heavy cream

Step One – Mix together the powdered sugar and cornstarch in a medium bowl until smooth.

Step Two – Add the cream gradually while whisking constantly. Continue to mix until the mixture thickens slightly.

Step Three – If necessary, add more powdered sugar to achieve desired consistency.

Step Four – Use immediately or leave the frosting in the fridge for up to 5 days.

Other Methods To Thicken Frosting

There are many different types of ingredients that can be used to thicken icing. Some of which include:

• Agar Agar

• Gelatin

• Pectin

You may want to experiment with these options to see what works best for your favorite cake recipe.

How To Thicken Buttercream Frosting With Gelatin

Gelatin is a useful thickening agent that can make a runny buttercream icing the perfect consistency.

For this recipe, you will need:

• 1 envelope unflavored gelatin

• 1 cup cold water

• 3 cups heavy whipping cream

Step One – Sprinkle the gelatin over the cold water in a small bowl. Let stand for 10 minutes.

Step Two – Heat the cream gently in a large saucepan over low heat until bubbles form around the edges of the pan. Do not let the cream boil.

Step Three – Remove the cream from heat and pour into the gelatin. Stir well.

Step Four – Refrigerate the cream mixture until firm, about 4 hours.

Step Five – Beat the chilled cream with an electric mixer at high speed until soft peaks form.

Step Six – Fold the whipped cream into the gelatin mixture to form the desired consistency.

Step Seven – Use immediately or refrigerated for up to 5 days

How To Thicken Buttercream With Pectin

Pectin is a natural substance found in fruits and vegetables that works as a thickening agent and helps to set jams and preserves.

For this recipe, you will need:

• 1 tablespoon powdered pectin

• 3 cups heavy creams

Step One – Combine the pectin and cream in a medium saucepan and bring to a simmer over medium heat.

Step Two – Cook, stirring occasionally until the mixture reaches 220 degrees F.

Step Three – Cool completely before using.

Step Four – Refrigerate for up to 5 days.

How To Thicken Buttercream With Agar Agar

When it comes to thickening agents, agar agar is another good one. For this recipe, you will need:

• 2 teaspoons agar agar powder

• 1/2 teaspoon salt

• 1/2 gallon whole milk

• 1/2 pound unsalted butter

• 3 cups powdered sugar

• 1/2 vanilla bean

How To Thicken Buttercream Frosting

Step One – In a small saucepan, combine the agar agar and the salt. Bring to a boil over medium heat and cook for 1 minute.

Step Two – Pour the hot liquid into a blender and blend until it becomes a paste. Set aside.

Step Three – Place the milk in a medium saucepan over medium heat. Whisk and allow to come to a boil.

Turn off the heat and cover the pan. Allow the milk to sit for 30 minutes.

Step Four – Strain the milk through a cheesecloth or a fine-mesh strainer. Discard the solids left on top.

Step Five – Return the strained milk to the saucepan and place over medium heat.

When it begins to bubble, turn down the heat and allow it to simmer for 15 minutes.

Step Six – Melt the butter in a microwave oven or by placing it in a double boiler over medium heat. Once melted, remove from heat.

Step Seven – Add the agar agar paste to the milk and whisk vigorously until combined.

Step Eight – Transfer the mixture back to the saucepan and continue cooking over medium heat, whisking frequently, until the mixture thickens enough to coat the back of a spoon, about 20 minutes.

Step Nine – Remove from heat and stir in the powdered sugar.

Step Ten – Stir in the vanilla bean seeds.

Step Eleven – You’ll be left with a thick icing that you can use immediately or refrigerate for up to 5 days.

Will Buttercream Frosting Thicken In The Refrigerator?

Yes! The lower temperature in the refrigerator will thicken the frosting. Warm frosting can become over softened, making it harder to pipe out of a piping nozzle.

In addition to this, it is safe for you to store your buttercream frosting in the refrigerator for up to five days without any problems.

However, if you want to keep it longer than five days, make sure to bring it back to room temperature in a hot kitchen before using it again.

This will slightly loosen the buttercream frosting and make it easier to work with when it comes to icing your beautiful cake.

How To Store Buttercream Frosting For Long Term Storage

If you plan to store your buttercreams for several weeks, then you should follow these steps:

Step One – Place your buttercream frosting into an airtight container such as Tupperware.

Step Two – Cover the top tightly with plastic wrap so that no moisture can seep through.

Step Three – Make sure that there are no holes in the plastic wrap.

Step Four – Label the container clearly with the date and contents.

Step Five – Keep the container in the fridge.

Step Six – Once you’re ready to use the buttercream frosting, remove it from the fridge and let it come to room temperature before spreading it on your cake.

Can You Freeze Buttercream Frosting?

You may also freeze your buttercream frosting for later use.

Simply place the buttercream frosting into a freezer bag and seal them tightly.

When you’re ready to use it, simply defrost the buttercream frosting at room temperature.

In Summary 

Buttercream frosting is easy to thicken once you know how.

We hope after reading this article you have a better idea of how to thicken buttercream!

Good luck and happy baking!

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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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