Creamy, incredibly smooth and not as sickeningly sweet as some other buttercreams, learn how to make Swiss Meringue Buttercream in this detailed tutorial. With just 5 ingredients, this Swiss buttercream will become your go-to frosting recipe.
340gunsalted butter, slightly softened but cool and not greasy (3 sticks / 1 1/2 cups)
Rub vinegar around the inside of your mixing bowl, rinse out and dry. This will remove any grease particles that may interfere with the meringue whipping.
Heat about 1 inch of water in a medium saucepan until simmering.
Add the egg whites to a large heat-proof mixing bowl, then the sugar. Whisk together with a balloon whisk until combined.
Place the bowl over the simmering water and continue to gently whisk and stir for around 5 minutes, until the temperature of the mixture reaches 71C / 160F. Rub a little of the mixture between your fingers to make sure there are no sugar granules left. If there are still granules, remove from heat and keep stirring until they're gone. You can put it back over the heat if it's taking a long time.
While still hot, place the bowl in your stand mixer and fit a whisk attachment. Whisk on medium-high speed until the meringue reaches stiff peaks, making sure the bowl and meringue have cooled to at least room temperature. If you have stiff peaks but it's not cooled enough, you may set it aside until it does. Don't add butter if it's still warm or it will melt.
Swap to the paddle attachment, then add the butter about 1 tablespoon at a time and beat at medium-high, until it's mixed in before adding the next tablespoon. Continue like this until it's all combined.
It should be looking thick, smooth and creamy. If it's not looking thick or holding it's shape, place the bowl in the fridge for 10 minutes before whipping again. It should thicken up.
Add the vanilla and salt and mix for a good 20 seconds to make sure it's all combined.
The swiss meringue buttercream is now ready to use.
This recipe will work best if you weighh the egg whites and sugar.
Granulated sugar will work but caster / superfine is best as it dissolves quicker. Don't use icing / powdered.
Yield 4 cups, which is enough for piping the 8 inch, 3 layer cake you see in the post. It will frost 12 cupcakes generously.
If the buttercream is looking soupy or runny, just place it in the fridge for 10 minutes, then whip again and it will thicken up.
If you're mixer is overheating, feel free to stop for a little to let it cool.
Swiss meringue buttercream will keep for 1-2 days at room temp (20C / 68F) or in the fridge for up to 5 days.
If you store it in the fridge, unless already piped onto a cake or cupcakes, you can let it come to room temperature and give it a whip to make it smooth and creamy again.
If the mixture looks curdled at any point, don't worry, it's quite common. Just keep beating and it will come together.
For more tips on flavouring or troubleshooting and how to store swiss meringue buttercream, please see the post.