Create a beautiful canvas for your buttercream flowers and decorations. This crusting buttercream frosting recipe makes it easy to add finishing touches to your cake.

cake frosted with a crusting buttercream frosting and decorated with blue buttercream flowers

Want to know the secret to getting that nice, smooth finish on your cake? It’s all in the frosting! Crusting buttercream (or frosting that lightly sets) is perfect if you need your frosting to keep its shape. You can use it for cake decorating, piping swirls on cupcakes or for making buttercream flowers.

What is Crusting Buttercream?

When a frosting crusts, it means the top layer of frosting has set. At this point, it can be lightly touched and decorated without leaving a mark. However, not all frostings possess this power.

Traditional buttercream frosting (what some call American buttercream) is a great choice if you’re looking for a frosting that crusts. It has the perfect ratio of fat to sugar, which is essential for crusting. If there’s too much fat or moisture, the frosting will never form a crust.

Whipped cream frosting, cream cheese frosting and most meringue-based buttercreams are more delicate than traditional buttercream and will not crust easily. If you’re making a cake that will be intricately decorated with piping techniques, you’re better off using our standard traditional buttercream recipe.

How to Make Crusting Buttercream Frosting

Making a crusting buttercream is actually very simple! For a buttercream to crust, you need the right ratio of fat to sugar. Our Easy Vanilla Buttercream recipe is a great go-to, plus it tastes delicious!

Crusting Buttercream Recipe


  • ½ cup unsalted butter, softened
  • ½ cup solid vegetable shortening
  • 1 teaspoon vanilla extract
  • 4 cups sifted confectioners’ sugar
  • 2 tablespoons milk, heavy cream or water
  • Pinch of salt (optional)

Step 1: Using a hand mixer (or an electric mixer with the paddle attachment) cream the butter and the shortening together on medium speed until it’s light and fluffy. This should take about 1 minute.

butter inside of a mixing bowl

Step 2: Add the vanilla, scraping down the sides of the bowl as needed.

mixing ingredients into crusting buttercream frosting

Step 3: ​Turn the mixer to low speed. Gradually add the confectioners’ sugar, 1 cup at a time, then beating well on medium speed. Scrape down the sides of the bowl as needed to help everything incorporate!

mixing ingredients into crusting buttercream frosting

Step 4: ​Once all the sugar has been mixed in, your frosting may appear dry and stiff…that’s okay! We’re going to fix that next.

mixing ingredients into crusting buttercream frosting

Step 5: ​Gradually add milk (or heavy cream or water), a little at a time until the desired consistency is reached. Continue to beat at medium speed until light and fluffy. If your frosting is too sweet for your liking, you can add a pinch of salt to help even out the sweetness.

mixing ingredients into crusting buttercream frosting

Step 6: ​And now you’re ready to decorate!

frosting cake with crusting buttercream frosting

How Much Frosting Does this Recipe Make?

This recipe yields about 2 cups of buttercream, enough to cover a 2-layer cake or frost about 24 cupcakes. This recipe can easily be divided in half if you only need a small amount of frosting. On the other hand, it can be doubled if you have a lot of treats to decorate!

How Long Does it Take for Buttercream to Crust?

The amount of time it takes for the buttercream to crust depends on a couple factors, especially the temperature and humidity inside your kitchen.

Generally, it will take your buttercream anywhere from 10 to 30 minutes to develop a crust. If it’s a particularly warm and humid day, it may take longer. You will know it’s ready when you can very lightly touch the surface of the buttercream and it does not leave a mark.

Is Buttercream Better with Butter or Shortening?

Actually, it’s best with both! Our buttercream uses a combination of the two fats. The butter gives the frosting flavor while the shortening provides structure.

If you’d rather not use shortening, you can replace it with all butter. However, it will take longer for your frosting to crust.

For a super white frosting that will hold its shape well (like for a wedding cake), you can also replace the butter with all shortening.

In the end it all comes down to personal preference and how you’re planning to use your buttercream.

Why is My Buttercream Not Crusting?

If your buttercream isn’t developing a crust, it may be too humid in your kitchen. Try placing your cake somewhere cool to help the crust form.

Another reason your buttercream may not be crusting is that there’s too much moisture in the frosting itself. If your frosting is too wet or soft, keep adding confectioners’ sugar until the consistency improves.

It’s also important that your cake is at room temperature before you start decorating. If your cake is too warm, the buttercream will melt and the frosting won’t set. If your cake is chilled, it can create condensation between the frosting and the cake. That moisture will prevent a crust from forming.

Why is my Buttercream Not Firm?

If your buttercream is too soft or is drooping after you pipe it, try adding more confectioners’ sugar. Weather plays a big part in making buttercream. If there’s a lot of moisture in the air, you may need to add more sugar than usual.

If your frosting is too dry, you can thin it out with milk or water. Be sure to start small, though. Even a teaspoon goes a long way!

Can I Use High Ratio Shortening?

High ratio shortening is 100% fat that many professional bakers use in their buttercream. It behaves a little differently than traditional store-bought shortening, so it needs to be used differently in recipes.

Our buttercream recipe was developed using traditional solid vegetable shortening. It was not tested using a high ratio; therefore, we do not recommend using it as a replacement in this recipe.

How Do You Store Crusting Buttercream?

Buttercream can be stored in the refrigerator in an airtight container. Be sure to bring it up to room temperature and re-whip it again before using it.

You can also freeze buttercream for up to 6 weeks. Check out our post on How to Store Buttercream Frosting for more hints and tips!

Do you have any time-tested buttercream tricks and techniques? Let us know in the comments below or tag us on Instagram @Wiltoncakes.

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