How to get sharp edges on a cake can feel like the hardest part of cake decorating. You can spend ages getting the sides smooth but the top edge still ends up rounded or uneven. In this tutorial you’ll learn how to get sharp edges on a cake using three different methods. My tips and tricks will help you create sharp buttercream edges every time.
Before trying any method, there are two things that make the biggest difference when you’re learning how to get sharp edges on a cake.
First, your cake needs straight sides. When assembling your cake, place each layer directly on top of the previous one and chill the cake before frosting. If you frost it straight away, the layers will shift as you spread and scrape the buttercream, causing the cake to lean. Straight sides are essential for sharp corners.
Second, your buttercream needs to be the right consistency. If it’s too thick or full of air bubbles, you’ll see small holes and uneven texture in your frosting. To fix this, stir your buttercream quite aggressively to knock out air bubbles. If it’s too stiff, add a little milk to thin it out. You can also use a microwave trick: scoop out about one third of the buttercream, microwave it for 10 seconds, and then mix it back into the rest. This creates a smooth, creamy consistency that’s ideal for sharp buttercream edges.
This is the quickest method for getting smooth cake edges and neat corners.
As you spread buttercream onto your cake, push it out over the edges on the top. When frosting the sides, push the buttercream slightly above the top edge to create a lip of frosting all the way around the cake. This extra buttercream is what allows you to form sharp edges instead of rounded ones.
To create the edge, swipe sideways with an
Wipe your spatula clean after each swipe so you don’t drag buttercream back onto the edge. This method is fast and effective, and it’s a great starting point if you’re learning how to get sharp edges on cakes.
For even sharper results, you can use a knife to create a precise 90 degree angle from the sides to the top of the cake.
After frosting your cake, place it in the fridge for about 30 minutes so the buttercream firms up. The frosting should feel firm to the touch before you start.
Dip a sharp knife into warm water, dry it, and then slice through the lip of buttercream around the top edge. Lift off the excess frosting, clean your knife, and repeat.
Hold the blade flat and horizontal as you cut, so you create a clean, straight edge. This method gives the sharpest corners and works well for both smooth frosting and textured designs.
Using acrylic discs is one of the most reliable ways to get perfectly sharp buttercream edges.
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Choose a disc that’s about 1/4 inch wider than your cake pans. For example, for a 4 inch cake, use a 4 1/2 inch disc.
Trace the disc onto parchment or wax paper and cut out a circle slightly smaller than your cake. Frost the top of your cake, place the paper circle on top, and secure the acrylic disc with a few small blobs of buttercream.
Check that the disc is centred by spinning the cake. It should stick out evenly all the way around, otherwise you’ll expose the cake when smoothing the sides.
Frost the sides of the cake and use a cake scraper to smooth the buttercream until it’s flush with the edge of the acrylic disc. The disc acts as a guide, helping you achieve straight sides and sharp edges.
Chill the cake until the frosting is firm, then carefully remove the disc and peel off the paper. You’ll be left with very clean, sharp edges.
If you notice any small imperfections after removing the disc, you can touch them up by spreading a bit of leftover buttercream over those areas and scraping again. Because the rest of the frosting is cold and firm, you won’t damage it, which makes this method especially forgiving.
All three methods can give you sharp edges on a cake, but they each have different advantages: The
Learning how to get sharp edges on a cake takes a bit of practice, but the results make a huge difference to the overall look of your cakes.
With the right buttercream consistency, straight cake layers, and one of these three methods, you can create smooth cake edges and clean, professional-looking corners every time.
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You can also watch a video of this tutorial on how to get sharp edges on a cake:
