Why do Buttercream Cakes Crack?
I’m convinced that you’ve also encountered this situation where you open the fridge and notice that the buttercream-covered cake you just made has small or large cracks on its surface, thus ruining your expectation of a perfect cake. It’s happened to me quite a few times, and I’ve wondered what I did wrong and how to fix it. So, let’s see what are the main reasons or answers to this question of why buttercream cracks on the surface of a cake.
- Unstable or soft buttercream – this is one of the main causes of cracks. This can occur due to a recipe mistake, short waiting time between different layers of buttercream, or incorrect whipping texture. You can correct the texture of the buttercream by either using a different recipe of making sure that the butter is at room temperature before using it.
2. Wrong proportion of sponge cakes and filling – a cake with too thin sponges and a lot of cream between them has a higher chance of cracking than one made in a medovik style, i.e.: equal layers of sponge cakes and cream. Ideally, the sponge cake and the filling should have about the same height, thus creating a more stable structure.
3. Too much syrup – yes, I know we love syrup, but too much moisture will alter the structure of a cake, leading to cracks.
4. Soft filling or a filling that has not had time to stabilize in the fridge – as much as I like a runny filling into a cake, it’s worth considering that anything liquid in a cake has a chance to ruin its structure and modify its shape. The same applies to inserts, especially those with pectin. Recently, I received a message from a student who used a different brand of pectin than usual and found that the jam didn’t set properly. Since the jam was frozen when she put it in the cake, she didn’t notice and, as a result, when she took the cake out of the fridge the next day, the filling started to leak on the sides, through the buttercream and the cake itself started to look lopsided.
5. Insufficient refrigeration time for the cake – I recommend at least 8 hours of refrigeration for any cake, sometimes more. This time is necessary to allow the sponge cake (the sponge is the main structural element, along with gelatin and cocoa butter) to absorb moisture, gelatin to work and butter to set, etc. The question that arises is “can we make a cake in just a few hours?” Yes, we can do it, but we take into consideration that some things might not turn out as planned!
6. Temperature shock – sometimes, in an effort to speed up the process, we put the cake in the freezer, right? The surprise comes when we take it out and see cracks on the surface of the buttercream coating. Temperature shock is responsible here – butter or chocolate contracts rapidly under negative temperatures, causing cracks.
7. The cake was covered when it was frozen or semi-frozen – this reason is closely related to temperature shock discussed above because it’s all about sudden changes in temperature. The rule is that a cake should be refrigerated before being covered in cream, never frozen!
8. The cake board was too thin – I intentionally left this particular reason at the end of this article because it is also very common. Imagine a cake where everything is perfect in terms of structure, but it’s placed on a thin cake disc/board. When you manipulate it, take it out of the fridge, place it on your work surface repeatedly, you probably lift one part of the disc. What happens when you lift only one part of a fully set cake? It cracks because you force it to change its shape. Therefore, I recommend using thick cake boards!