So this post is to answer the mother of all questions. I got so many messages, emails and posts about this question I have decided to dedicate a whole Ask Me Anything Post to answer it. In fact, I think no one will have anything else to ask me after this 😛
How do you get those sharp edges on your cakes?
Ok so sharp edges on a cake is not magic. It’s about using the right ingredients (ganache), setting up the cake correctly and using the right pressure when dealing with the fondant.
The most stable way to set up a cake is to use ganache. I don’t use buttercream because it does not set hard (unless it’s placed in the fridge but then that is another whole basket of problems). So please don’t ask me how to get sharp edges using buttercream. If you really must have buttercream in your cake, I would suggest filling the layers with buttercream and using ganache for the sides and top – kind of like creating a shell.
Once the cake is ganached properly (sides are straight and top is flat) with nice sharp edges, you will find that it also sets nice and hard. If needed, you can use a spatula dipped in hot water to smooth out any lumps and bumps. I usually let my ganached cake sit in an air-con room overnight before covering it.
If you don’t have a solid foundation like the above it will not be possible to achieve the final result.
When you roll out the fondant to cover the cake, it needs to be around 3 – 5mm thick. Too thin and it becomes really hard to cover the cake and the fondant will become see through. Too thick and you are guaranteed not to get neat sharp edges.
Once you cover the cake, you will find that that if you have done the above correctly, the sharpness of the edges will begin to show. All you need to do now is to smooth the cake and sharpen the edges a little more.
This is done by using two smoothers like shown below. You need to place equal amounts of pressure and work on going back and forth along the edges of the cake in smooth strokes. This is where you need to practise to understand the amount of pressure you need to use to achieve your sharp edges.
I promise, it’s not hard. But it does take practise and getting all the above elements correct.