Swiss meringue buttercream is the best kind of buttercream….in my personal opinion at least.
It’s always so smooth and silky, it’s less sweeter than a regular degular American buttercream and it also has a great flavour.
I’ve been using this recipe for a few years now, but I didn’t have a full written recipe for it up on this blog. That is not ok, so let’s get into it!
Ingredients for the Swiss meringue buttercream
Here’s the ingredients you are going to need to make this buttercream:
- Egg whites – you could use fresh egg whites or the ones from a carton.
- Granulated sugar – in a typical American buttercream, icing/powdered sugar is used. But make sure to use granulated sugar for this one.
- Salt – just a small amount to help enhance the flavours
- Unsalted butter – I like to use unsalted butter and then add the salt separately, just so that I can control the amount of salt. I’ve found that using salted butter can make the buttercream too salty sometimes.
- Vanilla extract – using vanilla in Swiss meringue buttercream is very important, without it the buttercream will taste a little too buttery.
Fresh egg whites or egg whites from a carton?
Like I mentioned, you can use either. There is a slight difference though.
The main difference is the way these egg whites whip.
Fresh egg whites always whip up so much better, I don’t know the science behind it, but they do. It’s a little more difficult getting stiff peaks from egg whites from a carton.
I personally have never been able to get egg whites from a carton to whip up into stiff peaks.
This is why most meringue recipes usually recommend using fresh ones.
However, for this buttercream, the stiffness of your egg whites is not a huge deal. The goal isn’t to make a Swiss meringue, the goal is to make a Swiss meringue buttercream.
Therefore, either one works works. It’s up to you what you use.
I prefer to just use egg whites from a carton, because the recipe needs 6 eggs. If I use fresh egg whites, I will have 6 egg yolks leftover.
I don’t like having to do to something with these yolks, so I just use carton egg whites.
A few tips
Use an electric mixer
Pretty much every recipe I post can be made by hand. But this is one recipe that needs some kind of electric mixer. This can either be an electric hand mixer or a stand mixer.
A lot of whipping is involved in the making of this buttercream, you’re just not going to be able to be done by hand, unless you are making a very small batch.
When heating the egg whites and sugar, don’t walk away
The first step in making this buttercream is to heat the egg whites and sugar over some simmering water.
You want to keep stirring the mixture. If you leave it and walk away, there is a chance that your egg whites will start too cook.
Then you’ll end up having pieces of scrambled egg in your buttercream….this is very weird, we don’t want this.
Make sure the meringue has cooled before adding the butter
After the egg whites and sugar has been heated, you are going to whip it. This is the ‘Swiss meringue’ part of the Swiss meringue buttercream.
It’s important to keep whipping this until it has cooled down. You’ll be able to tell by touching the side of your bowl. At first it will feel hot, but eventually the bowl will feel more closer to room temperature.
This usually takes about 10 minutes of whipping.
If it is too hot, once you start adding the butter, the butter will just melt. Then you’ll end up with a very liquidy buttercream.
Use softened butter
If you use butter straight from the fridge, it won’t mix well into the meringue, it will be a disaster to be honest.
You want to use room temperature butter.
You don’t really need to wait for the butter to soften at room temperature. I just cut it up into cubes then heat it in the microwave at 10 second intervals until it feels soft.
MAKE SURE IT’S NOT MELTED, just soft. You should be able to easily press your finger into it.
Making the buttercream smooth and silky
Swiss meringue buttercream has a lot of air whipped into it, this is what makes it taste light and fluffy.
However, because of all this air, there is a lot of air bubbles.
If you’re using this to ice a cake, it can become a little difficult to get a smooth finish, because of all the bubbles.
Here’s how to get rid of these bubbles and get a smooth buttercream:
- Add a few spoonfuls of the buttercream into a separate bowl.
- Place this in your microwave and heat it until it’s fully melted.
- Pour this back into the rest of the buttercream.
- If using a stand mixer, switch the whisk attachment to a paddle attachment.
- Mix this buttercream on low speed for about 10 minutes.
This is going to make a HUGE difference, it will seem like a totally different buttercream after this 10 minutes.
Below are 2 pictures of the buttercream. The 1st one is what the buttercream looked like just after I had added all the butter. The 2nd is what it looked like after I added the melted buttercream and mixed it for 10 minutes.
In the 2nd picture, you can see that the buttercream is a lot smoother and silkier.
There are a few things that can go wrong when making a Swiss meringue buttercream, NOT TO WORRY, it is all fixable.
Here’s some things that can go wrong:
The buttercream turns into a liquid
Once you add the butter to the meringue, it will go through stages.
At first it will go turn into a liquid, then it will start looking curdled, and then eventually the buttercream will come together. So just keep mixing, it will be fine.
However, if it turns into a liquid and it is just not coming together even after whipping it for a while, something went wrong. You most likely added the butter whiles the meringue was still too warm, so the butter melted.
This is ok, just put your bowl in the fridge for about 30 minutes, then take it out and whip it again and it will come together!
The buttercream curdled
Again this is one of the stages, it will curdle slightly and then come together.
But sometimes Swiss meringue buttercream can curdle a lot, and mixing it won’t fix it.
This usually happens because it is too cold, so either cold butter was added, or you put the buttercream in the fridge because you made it ahead of time. But then you didn’t wait long enough for it to come to room temperature before mixing it.
Once again not to worry, it is an easy fix, your buttercream is just too cold.
So get a few spoons of it, melt it, the add this into the rest and mix for a bit. This will warm up the buttercream, so after some mixing, it will be smooth again.
The buttercream looks yellow
All buttercreams will have a slight yellow undertone, just because they have a lot of butter in them.
Swiss meringue buttercream is a lot whiter than other kinds of buttercream, but it still does have a slight yellow colour.
Personally, I don’t mind this so I don’t do anything about it. But if you wanted to get rid of these yellow tones, use some purple food colouring.
It might sound weird, but purple food colouring will cancel out the yellow tones and make the buttercream look whiter.
There’s probably better explanation out there on why this works, it’s something about the positioning of yellow and purple on the colour wheel….I don’t know exactly. But it works.
Just make sure to use a very small drip of purple food colouring, otherwise you will end up with purple buttercream.
What to do with leftover Swiss meringue buttercream
If you ever have any left over Swiss meringue buttercream, there are two ways to keep it.
Put it into an airtight container and then either leave it in your fridge or freezer. It can stay in the fridge for up to 5 days, and in the freezer for up to 3 months.
You could also do this if you wanted to make the buttercream ahead of time.
Just make sure that the day you want to use it, take it out of the fridge/freezer the night before and leave it at room temperature.
Then when you’re ready to use it, put it in your mixer and mix it with a paddle attachment for 10 minutes, just to make it smooth again!
Flavouring the buttercream
It is extremely easy to flavour Swiss meringue buttercream, there’s so many different ways to do it.
This is just a simple vanilla version, but if you’re feeling chocolate, add some cocoa powder. Or I just prefer to add melted chocolate. I always use dark for maximum chocolate flavour but milk or even white chocolate works too.
If you want a fruit flavoured one, make a puree out of whatever fruit you want and mix it into the buttercream. Or you could also just buy a jam and add it in.
Adding some salted caramel also makes it taste amazing.
All I’m trying to say is, you can make this whatever kind of flavour you want!