Welcome to the Cake Decorators Q&A

asked February 13th 2021

White spots with buttercream

Hi, I made a cake today and the icing was buttercream with white chocolate ganache. I faced two problems and I have no idea what’s going wrong.

1) after having iced the cake white/yellow butter like spots have appeared all over the cake. Do you know what could be causing this?

2) having used the acrylic plates I iced the cake and popped it in the fridge for it to firm up before I could use the scraper to smooth it. When I went to smooth the cake the icing started to scrape off really weirdly like flaking completely rather than smoothing.

I have taken a photo of both after getting upset the cake is ruined and not my best work. It’s for an anniversary of a family member but I am very disappointed.


Hi aisha siddiq

This sounds like the oils in the buttercream/ganache mixture separated causing deposits of discolouration. It can happen if the ganache was slightly warm when combined with the buttercream or if it had split when made. The flakiness suggests perhaps the cake had set up too firm to smooth. Smoothing the cake with a hot scraper or palette knife will correct this issue.

If you still feel unhappy with it, a final fresh coat of icing will rescue any blemishes. 🙂


Hiya. How do you mean split when made?
I used a hot scraper to smooth but it was still causing that issue. I’ve taken pictures is there a way of sharing pictures?

Thanks for a quick response


The composition of white chocolate is mainly cocoa butter, it contains very few cocoa solids, which makes it vulnerable to splitting or burning if the ganache is made using boiling cream.

When the cocoa butter separates from the solids it becomes a yellow liquid resembling oil. Once this happens, the cream and chocolate do not emulsify into a smooth ganache, instead, it will resemble oily cottage cheese. The ganache can be rescued by adding to it a couple of tablespoons of cold cream and mixing it until it binds back together. Alternatively, pop it in the fridge until almost set and then whisk it on medium speed for a minute, to help bring it to a workable consistency. Don’t over mix as this makes the ganache become grainy and unworkable.

The broken ganache will not spread smoothly on a cake. The use of a hot scraper or palette knife will not remedy the problem because the ganache itself is broken. The technical term is the emulsion has cracked.

Unfortunately, there is no way of sharing pictures on this platform. However, all paid-up members of Cakeflix can join the Cakeflix family private Facebook page where pictures and advice can be shared.

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