This silky smooth Swiss Meringue Buttercream recipe is much easier to make than you probably think! Today I’ll be walking you through all of the steps for this classic frosting recipe! Recipe includes a video tutorial.
A Guide to Swiss Meringue Buttercream
A new recipe to add to our frosting library today!
We’ve covered some of my favorite simple recipes in the past (cream cheese frosting, I’m looking at you) but Swiss Meringue Buttercream is one that requires just a bit more patience and technique than your average frosting.
It’s not hard to make, but if you’ve mostly made your frostings without egg whites and away from the stovetop in the past (as I did for decades), this might be a little different for you.
My first taste of this frosting was when Zach and I went for our cake testing for our wedding. I was positive that I did not want a buttercream frosting because I thought all buttercreams were like American buttercream: super sweet and overwhelmingly sugary. This frosting gave me a whole new appreciation for buttercream and ended up being the frosting we chose to ice our cake (well, I chose. Zach didn’t even sample the cake!)! So, what’s so special about this icing?
Swiss Meringue Buttercream is:
- Silky smooth
- Pipes beautifully and is great for decorating (and using under fondant)
- Has a light, silky, buttery mouthfeel
- Doesn’t crust or harden like American Buttercream
How to Make Swiss Meringue Buttercream
We start by first making a meringue. If you’ve ever made my meringue cookies before, this step should be familiar to you. However, unlike with my cookies, we will not be baking this recipe, so it’s important that we heat our egg whites until they reach a temperature where any bacteria that might be lurking is destroyed.
We’ll be heating our egg whites along with our second key ingredient: granulated sugar. Unlike my other frosting recipes, this recipe needs granulated and not powdered sugar in order to work properly.
As we heat the egg whites and sugar together, the granulated sugar will dissolve. The sugar must dissolve completely for your meringue to turn out right. To test that it has, rub a small bit between your fingers before proceeding to the next step. If you can feel any grit or grain at all, your sugar is not fully dissolved and you’ll have a gritty buttercream, so keep whisking until all the sugar is dissolved.
Once your sugar is dissolved and your mixture is heated to at least 160F, it’s time to move our mixing bowl over to our stand mixer and start beating. I strongly recommend using a stand mixer for this recipe. Doing this step by hand or even with an electric mixer is going to be a workout. I can’t even imagine how long it would take.
Use the whisk attachment of your stand mixer and beat your syrup mixture until it is thick and glossy and stiff peaks have formed. “Stiff peaks” means that if you lift the whisk straight out of your meringue, the peak that forms holds its shape and doesn’t melt back into itself or fold over (see photo below, and excuse my face please). This will take at least ten minutes or so.
Don’t go any further until the bottom of your bowl is completely cool and not even a tiny bit warm to the touch! You can continue to beat your meringue until the bowl is no longer warm, but keep in mind that the meringue gets very thick and this can be pretty taxing on your mixer, so once I’ve achieved stiff peaks I like to give my mixer a break while the bowl cools completely. At this point I also like to switch over to my paddle attachment for a smoother whip.
And Now For The Butter
Now comes the butter! It is important that your butter be softened, but it also shouldn’t be so soft that it’s melting out of your butter wrapper. I’ll usually set mine out of the fridge about an hour before I begin making my buttercream.
With your mixer running on medium speed, add your butter one tablespoon at a time. Don’t add the next tablespoon until the first is fully incorporated into the meringue.
Now just keep adding your butter (slowly, one tablespoon-sized slice at a time), and keep mixing!
Help! My Buttercream is Curdled!
Sometimes during the process of adding your butter, the buttercream might break down and take on a curdled appearance. Don’t panic! So long as you’ve followed all of the previous steps correctly, everything is going to be just fine. Just keep mixing, just keep mixing, and by the time all of your butter is added the buttercream should come back together. If it doesn’t, transfer your mixer bowl to the refrigerator for 10 minutes and then try mixing again. Serious Eats has a great guide on rescuing Swiss Meringue Buttercream if you find yourself convinced you’ve ruined everything!
When your frosting is finished, it should be thick and smooth. Scrape the sides and bottom of the bowl, add vanilla extract (or whatever flavoring/coloring you would like!) and stir again.
What is the Difference in Swiss Meringue Buttercream and American Buttercream?
If you’ve ever made my my vanilla frosting, you’ve tried American buttercream. American buttercream is very sweet (almost too sweet for me, even!) and is made primarily of butter and powdered sugar. Swiss meringue buttercream is less sweet and is made primarily of granulated sugar and egg whites (which we will use to make our meringue), and butter. Unlike American buttercream, Swiss doesn’t crust or harden and (as you’ve seen above) the technique for making Swiss Meringue is quite different.
Does This Frosting Need to be Refrigerated?
A cake (or cupcakes) frosted with Swiss Meringue Buttercream can be left out at room temperature (preferably in an airtight container) for up to 2-3 days. Beyond that I recommend refrigerating. If you’d like to store this frosting, I recommend storing in the refrigerator in an airtight container. A cake or cupcake frosted with this icing can be left out at room temperature (preferably in an airtight container!) for up to 2-3 days. Beyond that I recommend refrigerating.
Will It Hold up to Heat and Humidity?
Unfortunately Swiss Meringue Buttercream does not fare well in the heat. While the meringue does help to add some structure to the frosting, all of that butter is going to want to do what butter does in the heat: melt! While you can keep this frosting at room temperature and it will hold its shape wonderfully, it will start to melt or become very soft in hotter temperatures or if served outside on a warm day.
Can I use Swiss Meringue Buttercream Under Fondant?
Yes! This recipe is great for using under fondant.
This frosting goes great on any of these cakes or cupcakes!
- Vanilla Cake
- Chocolate Cake
- Chocolate Cupcakes
- Vanilla Cupcakes
- I also understand that some people like to use it over Tres Leches Cake instead of the whipped cream frosting.
And Stay Tuned! On Wednesday I’m using this buttercream recipe to frost a batch of Gender Reveal Cupcakes! What do you think: boy or girl?!?
Swiss Meringue Buttercream
- 6 large egg whites¹ make sure there is not even so much as a tiny bit of yolk mixed in with the egg whites or they won’t whip properly. (7.5 oz/210g/210ml)²
- 1 3/4 cups granulated sugar 350g
- 1/4 scant teaspoon salt just ever so slightly less than 1/4 teaspoon
- 2 cups unsalted butter cut into Tablespoon-sized pieces. Butter should be room temperature but not melt-y/oily, still solid enough to cut, but softened (455g)
- 1 1/2 teaspoons vanilla extract
- Thoroughly clean and dry the bowl of a stand mixer. Make sure there is absolutely no grease or water on the inside of the bow (or on your whisk, or anything that will come in contact with your egg whites) or your egg whites will not whip properly.
- In your (clean) mixer bowl, combine egg whites, sugar, and salt and whisk until combined.
- Heat about 1 1/2 inches of water over medium-low heat in a medium-sized saucepan and bring to a simmer. Make sure that you are using a saucepan that your mixer bowl can fit in without touching the bottom of the pan or touching the water.
- Rest the bowl of your mixer in the pot over the simmering water.
- Whisk egg white/sugar/salt mixture constantly until the sugar is dissolved and mixture is no longer grainy (if you rub a small bit between your fingers it should feel smooth and not at all gritty) and the mixture reaches 160F (70C). This will take several minutes.
- Remove mixing bowl from heat and dry the bottom of your bowl. Fit bowl into your stand mixer.
- Using a whisk attachment, beat the egg whites on medium/medium-high speed until meringue is thick and glossy and you have achieved stiff peaks (see photo in post or see video below for visual). This will take about 10 minutes or so.
- Once you have achieved stiff peaks, stop beating and allow bowl to cool down completely. The bowl must no longer be warm to the touch anywhere before proceeding or you will melt your butter and ruin your buttercream.
- Once bowl is no longer warm to the touch (make sure you are feeling near the bottom of the bowl), switch out whisk attachment for paddle attachment. Turn mixer to medium speed and add butter one Tablespoon at a time. Don’t add the next tablespoon of butter until the previous one is incorporated into the meringue. If you notice that your buttercream starts to break down or look curdled, just keep mixing and it will come together. If it still doesn’t come together (it could take some time), place the mixer bowl in the fridge for about 10 minutes and then try mixing again.
- Once all butter has been beaten into the meringue, scrape down the sides of the bowl and stir again. Beat on medium/high until smooth and thick.
- Stir in vanilla extract or other flavoring and any food coloring, if using.
- Spread or pipe over cupcakes or cake! I used an Ateco 848 for the cupcakes shown in this post.
Making in Advance/StoringSwiss Meringue Buttercream may be made several days in advance of using it. Store refrigerated in an airtight container and then allow frosting to come to room temperature and stir well before using. If the buttercream seems to have lost some of its volume/lightness, use an electric mixer to whip it until it returns to its original texture.
Here are a few recipes to use up your leftover egg yolks!
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