Why Is My Buttercream Cracking?
Understanding the Two Most Common Types of Buttercream Cracks
There’s nothing more frustrating than achieving a beautifully smooth buttercream finish, only to notice cracks appearing later.
Many decorators assume the buttercream recipe is to blame.
In reality, the location of the crack often tells you exactly what’s causing the problem.
Over the years, I’ve found that the two most common buttercream crack patterns are:
- Vertical cracks that run up the side of the cake.
- Horizontal cracks that appear near the cake board.
While buttercream can crack for other reasons, these two patterns usually point to very different underlying problems.
Understanding the difference makes troubleshooting much easier – and helps you prevent the cracks from happening in the first place.
Type 1: Vertical Buttercream Cracks
Vertical cracks usually run up the side of the cake.
These cracks usually indicate movement within the cake itself.
One of the most common causes is decorating a cake that is still partially frozen.
Why It Happens
One of the most common causes of vertical buttercream cracks is decorating a cake that is still partially frozen.
As the cake gradually thaws, it naturally expands ever so slightly. If the buttercream has already set before the cake has finished thawing, that movement places stress on the surface, often resulting in a vertical crack.
This is one of the reasons I recommend decorating cakes that are cold, but not frozen.
Vertical cracks can also be caused by movement inside the cake for other reasons, including:
- Cake layers settling after stacking
- Air pockets trapped between layers
- Soft or unstable fillings
- Decorating before the cake has fully settled
- Tall cakes without adequate internal support
With FunkyBattercream, this is especially important because it sets up quickly – much like ganache. That quick-setting nature is what creates smooth finishes and sharp edges, but it also means the buttercream becomes firm sooner. If the cake is still expanding as it warms, the buttercream is less able to accommodate that movement, making vertical cracks more likely.
If your cake also develops tiny water droplets as it warms, that’s a completely different issue called condensation. You can learn more about that in my article Why Is My Buttercream Sweating?
How to Prevent Vertical Cracks
- Decorate cakes that are cold, but not frozen.
- Allow stacked cakes to settle before applying the final coat.
- Remove trapped air pockets while stacking.
- Use stable fillings.
- Properly support tall cakes.
Type 2: Horizontal Buttercream Cracks
Horizontal cracks usually appear close to the cake board.
Unlike vertical cracks, these are less likely to be caused by movement inside the cake.
Instead, they’re often caused by movement in the cake board.
Why It Happens
Thin cake boards flex.
When you pick up the cake, transport it, or even lift one side slightly, the board bends.
That movement transfers stress directly into the buttercream around the base of the cake.
Since the buttercream has already set, it can’t stretch enough to absorb that movement, resulting in a horizontal crack near the bottom edge of the cake.
Unlike vertical cracks, horizontal cracks don’t always form a complete ring around the cake. They often appear as short cracks near the cake board, particularly in the area where the board has flexed the most.
How to Prevent Horizontal Cracks
The easiest solution is to use a cake drum instead of a thin cake board.
A sturdy cake drum is much more rigid, helping to minimize flexing while lifting, transporting or handling the cake.
I also recommend:
- Supporting the cake from underneath when lifting.
- Avoiding lifting the cake by one edge.
- Allowing the buttercream to set before transporting.
- Choosing a cake board that’s strong enough for the size and weight of your cake.
Does the Buttercream Recipe Cause Cracks?
In most cases, no.
Any buttercream can crack if the cake underneath moves.
The real cause is usually the cake itself – whether that’s a frozen cake expanding as it thaws, layers settling after stacking, trapped air pockets, or movement from a flexible cake board.
A good buttercream should complement a well-built cake, not compensate for poor structure.
If you’re looking for a smooth, stable buttercream that’s designed for cake decorating, you can find my FunkyBattercream Recipe here. The recipe includes a detailed video tutorial, success manual and troubleshooting guide to help you achieve consistent results.
What Is the Crack Telling You?
What the crack looks like
What it usually means
Running up the side of the cake.
This may be caused by the cake thawing, layers settling, trapped air pockets or unstable fillings.
Near the cake board.
The board bends slightly while the cake is lifted, handled or transported, placing stress on the buttercream near the base.
Frequently Asked Questions
Why did my buttercream crack after refrigeration?
If your cake was still frozen when you decorated it, the cake may have expanded slightly as it thawed, putting stress on the buttercream.
If you also notice moisture forming on the surface, read my article Why Is My Buttercream Sweating? to learn why condensation happens and how to reduce it.
Can buttercream crack if the cake is frozen?
Yes.
Decorating a partially frozen cake is one of the most common causes of vertical buttercream cracks because the buttercream sets before the cake has completely thawed.
Why did my buttercream crack around the bottom of the cake?
A crack near the cake board is usually caused by movement in a thin cake board.
Switching to a sturdy cake drum is one of the simplest ways to prevent this.
Does buttercream crack while transporting a cake?
It can.
Transporting a cake on a thin or flexible cake board allows the board to bend slightly, transferring stress into the buttercream around the base of the cake.
Does It Happen to Any Frosting?
Yes.
Every frosting behaves a little differently, but American buttercream, Swiss meringue buttercream, Italian meringue buttercream, French buttercream, Russian buttercream, Ermine buttercream, cream cheese buttercream, whipped cream and ganache can all develop cracks under the right conditions.
In most cases, however, the frosting itself isn’t the problem.
Cracks are usually caused by movement underneath the frosting—whether that’s a cake that’s still thawing, layers settling, trapped air pockets or a thin cake board flexing during handling or transport.
Choosing the right frosting for your project is still important, as each one has different strengths, stability and decorating characteristics. If you’re unsure whether to use buttercream, whipped cream or ganache, take a look at my guide Whipped Cream vs Ganache vs Buttercream – Which Should You Choose?
Final Thoughts
Most buttercream cracks don’t begin during decorating.
They begin much earlier – with cake temperature, stacking, settling, support and the cake board underneath.
Once you understand what’s causing the crack, preventing it becomes much easier.
Building a stable cake foundation doesn’t just make decorating easier – it helps your finished cake stay beautiful from the moment it’s frosted until it’s served.
That’s exactly why Cake Foundations is the first month inside the Funky Batter Club. Before we dive into buttercream colors, decorative techniques and advanced designs, we start by building the skills that prevent common problems like cracking, bulging and unstable cakes. Because once you have a solid foundation, everything else becomes easier.
Ready to Build Better Cakes?
If you’re ready to move beyond fixing problems and start preventing them, I’d love to welcome you inside the Funky Batter Club.
We’ll begin with Cake Foundations, where you’ll learn the techniques that create stable cakes, smooth buttercream finishes and the confidence to tackle more advanced decorating projects.
