December 6, 2021
How to Make Swiss Meringue Buttercream – Back to Basics!
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So say hello to a new back-to-basics blog post – how to make delicious homemade swiss meringue buttercream.
This is a recipe that has been requested over and over, so I thought I would give it the attention it deserves, and give it a blog post all to its own… swiss meringue buttercream.
If you aren’t aware, swiss meringue buttercream is different from the normal American buttercream frosting of unsalted butter and icing sugar, and different again to cream cheese frosting. It is genuinely a swiss meringue turned into the buttercream.
I did a back-to-basics blog post on cream cheese frosting as that is also a fairly difficult frosting to make sometimes, and I thought this one is on a similar level – it’s something that needs explaining in a bit of detail so you know exactly what you are doing!
Many people like swiss meringue buttercream because it is ‘less sweet’ and has a more mousse-like texture. I would still say it is fairly sweet, just in a completely different way to the classic American buttercream frosting.
I don’t see anything wrong with the classic cake topping, as it is just so easy – but the taste of swiss meringue is just beautiful. It’s so light it is like eating a cloud – but it is a bit more time-consuming to make so be prepared.
For swiss meringue buttercream, you have to start with making sure that the block unsalted butter is at room temperature. You don’t want to heat the butter in any way to make it room temperature though, you need to leave it naturally. How long this takes depends on the time of year – peak summer is probably only 30-60 minutes, whereas peak winter may be the best overnight.
The butter wants to be at a temperature where you can press your finger into the butter to indent it really easily, but it’s not melting away. You definitely do not want to use stork, margarine, or a baking spread of any kind for this.
Once you have done this, you can start the process of the swiss meringue. Swiss meringue is made using egg whites and sugar as your normal meringue is, but with a completely different method. There are a few other types of meringue such as french or Italian, but this time we are talking swiss!
With swiss meringue, you cook the egg whites out over a double boiler, whisking, until the sugar grains have dissolved. This takes a fair amount of time as you don’t want to go crazy with the heat, and the egg whites are meant to slowly heat using just the heat of the steam underneath.
For this recipe, I cook the meringues until they reach 72ºc – or 160ºf. Technically that translates to 71.11ºc, so I just went with 72ºc. It is so important to use a sugar thermometer when making this recipe as you really do need the temperature to be accurate! You can use regular sugar thermometers or a thermometer like this one.
When you are at this stage, other than checking the temperature, you need to carefully rub some of the mixture between your fingers – the mixture should be smooth. If there is a grainy texture, then the sugar hasn’t dissolved and may need to be heated further until it is.
I used a large glass bowl over a medium pan, with about 1.5” worth of water in the bottom. The bowl sits above the water, and doesn’t touch it – you want the water to be a simmer, so once it’s boiled, I usually leave it at a half level like 5.
Whisk the mixture constantly, until it reaches the temperature, and then transfer to a stand mixer bowl – I will say that using a stand mixer is SO much easier than anything else, but an electric hand whisk is still better than just your arm and a balloon whisk. All in all, this recipe takes about 45 minutes to make, with about 25-30 minutes whisking.
When you whisk the eggs and sugar in a spotlessly clean bowl, you need to whisk the mixture until it reaches a lovely meringue with glossy stiff peaks and the bowl is completely at room temperature – this takes about 20 minutes, if not longer. The meringue MUST be at room temperature, so you don’t melt the butter.
If the bowl feels even slightly warm, keep on whisking until it has cooled. I whisk at about 6/7 on my KitchenAid mixer – and it’s a fair amount of time to be whisking for. If you don’t use a stand mixer, you are going to have to stand and whisk in the same way until it’s cooled.
This is when you add the butter – you need to add small amounts of butter, letting it beat in fully each time. I switch my whisk to my paddle attachment at this stage as well. I add in about 1 tbsp of butter at a go – about 1” size cube of butter.
It is so important to not add too much butter, as it needs to mix in well. As you mix, the texture of the swiss meringue buttercream may change, and this is normal. You can find some troubleshooting tips below if you are worried!
Once all the butter is incorporated, add any flavouring such as 1 tsp vanilla extract, and beat for a further couple of minutes, scraping down the side of the bowl and making sure it’s combined. You should be left with a lovely delicious swiss meringue buttercream!
- If the mixture melts into soup, the meringue was still too hot. You need to cool the bowl in the fridge for 20+ minutes, or longer, and try to re-whisk.
- If the mixture turns lumpy, keep on beating. It can often look a little strange, but it’s worth beating out. If the butter was too cold however and you have flecks of butter, you need to gently heat the bowl, whilst mixing, with a hairdryer, to gradually heat until the butter has melted.
- If the swiss meringue buttercream is grainy, the sugar wasn’t dissolved at the beginning, and you can’t fix this, unfortunately.
Other information sources for Swiss Meringue Buttercream: Liv For Cake, Natashas Kitchen & Sally’s Baking Addiction.
Swiss Meringue Buttercream!
- 170 g egg whites
- 275 g caster sugar
- 250 g unsalted butter
- 1 tsp vanilla extract
- Make sure your block unsalted butter is at room temperature (see notes in the blog post).
- Make sure the equipment you are using is spotlessly clean. Any grease or anything else can ruin meringue really easily.
- In a medium pan, bring 1.5" worth of water to a simmer, and add a large glass bowl on top.
- Add the egg whites and caster sugar to the bowl, and heat over the simmering water, whisking constantly, until the mixture reaches 160ºF/72ºC (see notes in the blog post).
- Using a sugar thermometer or normal thermometer to reach the temperature, test the mixture carefully by rubbing some of the mixture between your fingers - there should be no grainy texture.
- This took me about 7 minutes.
- Once the temperature is reached, pour the mixture into the bowl, and whisk on a medium/high speed until the meringue is smooth and glossy, and the bowl is completely at room temperature. This took me about 20 minutes.
- The bowl should not be warm at all as it may melt the butter. Once the meringue is cooled, switch the whisk attachment to a beater attachment.
- Mixing at a medium speed, add the room temperature unsalted butter to the meringue 1 tbsp at a time (about a 1" cube of butter), letting the butter beat in fully each time.
- Once the butter has been added, add the vanilla extract and continue to beat for a further 2-3 minutes after you have scraped down the sides of the bowl.
- Decorate whatever cake you fancy - these quantities will work for 12x cupcakes, or a two layer 8" cake!
- Please read the blog post for my full tips & tricks on swiss meringue buttercream.
- Once made, this swiss meringue buttercream will last 2 days at room temp, or up to 5 in the fridge.
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Hi Jane, can you add food colouring to this? If so is it best added at the end?
Hiya! Yes & yes! Hope this helps! x
I’m going to give this a try. Can you tell me the quantity of buttercream I will need for a tall 6 inch cake ?
Hi, hoping for some advice please. I’m making a friends wedding cake & will be mid July so probably warm weather. She wants cakes covered in SMBC , then sugar paste Problem is, there is no air conditioning at the venue 😢. I’m also a guest at the wedding, so will have to set cake up in morning. Will it be ok left out until evening to cut?
Worried it will soften & will cause cake to bulge or not be stable! 😩.
Would I need to double the quantity of ingredients to fill and decorate an 8″ 3 layer cake?
Hi Jane, I’d like to make my smbc salted caramel, can I use tinned carnation caramel with sea salt, if so how much please? I am making a 4 tier version of your chocolate fudge cake with 2 x the above recipe thanks
Could you beat the butter first before adding to achieve a whiter colour?
Hiya! By doing this you risk the butter becoming too soft if you beat it first. Hope this helps! x
How would you convert into chocolate smbc?
If I have made 7 cupcakes how much stuff will I need please!
i just used what it said in the recipie
If use Carton of egg whites don’t have to cook the eggs do you ?
Danni, just a simple math formula! Divide each ingredient of the 12 cupcake recipe by 12 and then times it by the number of cupcakes you need to ice. Bang!!
Would this fill and decorate a 3 layer 6 inch cake?
Hi, how much smbc do you think I will need for a 10inch and 12 inch cake and what brand of butter would you recommend using?
Hi Jane. Do you recommend the eggs are room temperature or will they work from the fridge (like the carton ones) x
Hiya! I store my actual eggs at room temp, but i store my carton egg whites in the fridge – either of these will work for this! Hope this helps! x
How do you prevent excessive air bubbles in the swiss meringue buttercream? I find when covering the sides and top this is often a problem
Do you use a whisk or paddle? The whisk can definitely increase air bubbles, but also once mixed you can use a normal spatula and stir through the mixture. You can also heat your scraper slightly to get rid of air bubbles for a final run around of the cake x
Can you use egg whites from a carton or do they have to be fresh?
I used carton as it’s easier!!
Would I use this or traditional buttercream for my crumb layer?
Hiya! It doesn’t reallllly matter, but I would generally use a regular buttercream personally! x
This us excellent, thank you.
Once you’ve decorated a large cake, do you have to store the cake in a fridge? How long will it last and be safe to eat if left out of a fridge?
Thank you! As per the notes its about 2 days at room temp, or 5 days in the fridge. x
Hi, do you use egg whites in a carton or fresh eggs? How many eggs approximately are in this recipe? Thanks x
I used a carton – but a medium egg has usually 30-35g white inside, so maybe about 5?!