Extremely light, creamy, and not too sweet, Swiss meringue buttercream is the perfect frosting. If you're making Swiss for the first time or have tried and failed before, this recipe breaks down all of the techniques in easy detail and goes over all of the challenges and troubleshooting for making the best buttercream. If sweet frosting like traditional American buttercream is too sweet for you, you will love this recipe.
Making Swiss meringue buttercream frosting (also known as SMBC) is not hard, but it can be time-consuming. SMBC has a meringue base and is made by cooking egg whites and sugar, then whipping them to make a thick meringue, and whipping in butter. This recipe is the big sister of my mock-Swiss Easy buttercream frosting recipe, which skips the need to cook the egg whites by using pasteurized eggs.
Table of Contents
Swiss Meringue Buttercream Ingredients
Fresh egg whites will whip into a more stable meringue than carton egg whites. It's a bit more work to separate the eggs yourself, but you can then use the leftover egg yolks for lemon curd, Boston cream pie, or creme brulee. Heating egg whites to 110°F is recommended for safe consumption, however, I recently learned that most raw eggs in the US are already pasteurized, so they're technically safe to eat.
Vanilla is the main flavor of swiss buttercream, so it's important to use good-quality vanilla. Vanilla extract, vanilla bean paste, or even a vanilla bean would work perfectly. Nielsen Massey makes really great vanilla bean products and focuses on sustainable environmental practices.
How to Make Swiss Meringue Buttercream Step-by-Step
- Fill a large pot with about 2 inches of water and bring it to a simmer.
- Place the metal bowl of your stand mixer on top of the pot of water to create a bain-marie (or double boiler). The water should not touch the bottom of the bowl.
- Whisk together the egg whites, sugar, and salt in the mixing bowl. Pro-tip: Wipe your bowl out with white vinegar before making the meringue. A very clean metal bowl will work best for this as the meringue is easier to whip up in metal rather than plastic.
- Cook the egg white mixture until it reaches 110ºF (43ºC) and constantly whisk the sides of the bowl to distribute the heat evenly. If you don't have an instant-read thermometer, when you can no longer feel any sugar granules in the egg whites with your finger, it's done.
- Remove the bowl from the heat and transfer it to your stand mixer with the whisk attachment. You can use a hand mixer and a large bowl to mix your meringue, it will just take a lot longer to mix.
- Whip the egg and sugar mixture on medium-high speed for 10 to 15 minutes, or until you reach glossy, stiff peaks.
- Pour your meringue out into a shallow dish and refrigerate it for about 10 minutes to cool the meringue to room temperature. You can also put your entire bowl of meringue into the fridge, but it will take longer to cool. If you don't cool the meringue it will melt your butter and then you'll have buttercream soup.
- Once your meringue is cooled, put it back in your stand mixer bowl with the whisk attachment.
- Add the room-temperature butter, vanilla, and mix until it's all combined.
- Whip the buttercream on medium/high speed until it is white, fluffy, and doesn't taste buttery, this can take 8-10 minutes. Pro-Tip: To counteract the yellow in your buttercream, add a drop or two of violet food color gel to make it whiter.
- Switch to a paddle attachment and mix it on low speed for 15-20 minutes to make the buttercream very smooth and remove air bubbles. This isn't required, but if you want really creamy frosting, you do not want to skip it!
- This recipe is enough to frost and fill a two-layer 8" x 2" cake, or frost about 24 cupcakes. Store any leftovers in an airtight container in the fridge for 1 week, or freeze for up to 6 months.
FAQ
Yes, you can! Swiss meringue is very stable and makes a great base for using under fondant. I always refrigerate my buttercream cakes first before covering them to prevent bulging.
Italian buttercream is very similar to Swiss meringue but it is more stable. It involves boiling sugar to the hard crack stage and then drizzling it into your whipping egg whites. This makes the meringue very firm and more stable under high temperatures.
Although Swiss meringue buttercream is more stable than using whipped cream, it is still susceptible to high heat. Its main ingredient is butter after all, and butter WILL become very soft at around 80ºF and will melt fully at 90º after about 30 minutes in the sun. So it will melt, but so will any buttercream.
Yes, absolutely. You can refrigerate cakes with buttercream on them, you can store buttercream leftovers in the fridge for up to a week and you can freeze leftover buttercream for 6 months. Make sure you bring the buttercream back to room temperature and re-whip to get it nice and fluffy again before you use it.
Swiss meringue buttercream is ok to be left out for hours and hours. After about 8 hours it can get spongy though and lose its smoothness so it's best to refrigerate if you're not going to use it and then re-whip it. Cakes that are frosted in Swiss meringue buttercream can be left at room temperature for up to two days!
Yes, and to do that you will add in ¼ to ½ cup of your favorite cocoa powder or melted chocolate. Just whip it in at the end. I have a great recipe for chocolate Swiss meringue buttercream you will love as well!
You can add a few drops of gel food coloring to this buttercream to color it. It holds color well and gets darker overnight. Just be sure to not add too much food coloring or you'll be able to taste it. To make darker colors, add a few drops of food coloring, remove about a cup and melt it in the microwave, then whip it back into your buttercream.
Related Recipes
Chocolate Swiss Meringue Buttercream
Brown Sugar Swiss Meringue Buttercream
Moist Vanilla Cake and Easy Buttercream
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Note: measurements are estimated based off the vanilla cake recipe using standard US cake pans and sizes. Measurements used are for 2" tall cake pans only. Your results may vary. Do not overfill cake pans above manufacturer's recommended guidelines.
Recipe
Equipment
- 1 stand mixer with the whisk and paddle attachments
Ingredients
Swiss Meringue Buttercream Ingredients
- 8 ounces fresh egg whites about 8
- 16 ounces granulated sugar
- 24 ounces unsalted butter room temperature. You can use salted butter, but it will affect the taste and you need to leave out additional salt
- 2 teaspoons vanilla extract
- ½ teaspoon salt
Instructions
Making Swiss Meringue Buttercream
- Fill a large pot with about 2 inches of water and bring it to a simmer.
- Place the metal bowl of your stand mixer on top of the pot of water to create a bain-marie (or double boiler). The water should not touch the bottom of the bowl.
- Whisk together the egg whites, sugar, and salt in the mixing bowl. Pro-tip: Wipe your bowl out with white vinegar before making the meringue. A very clean metal bowl will work best for this as the meringue is easier to whip up in metal rather than plastic.
- Cook the egg white mixture until it reaches 110ºF (43ºC) and constantly whisk the sides of the bowl to distribute the heat evenly. If you don't have an instant-read thermometer, when you can no longer feel any sugar granules in the egg whites with your finger, it's done.
- Remove the bowl from the heat and transfer it to your stand mixer with the whisk attachment. You can use a hand mixer and a large bowl to mix your meringue, it will just take a lot longer to mix.
- Whip the egg and sugar mixture on medium-high speed for 10 to 15 minutes, or until you reach glossy, stiff peaks.
- Pour your meringue out into a shallow dish and refrigerate it for about 10 minutes to cool the meringue to room temperature. You can also put your entire bowl of meringue into the fridge, but it will take longer to cool. If you don't cool the meringue it will melt your butter and then you'll have buttercream soup.
- Once your meringue is cooled, put it back in your stand mixer bowl with the whisk attachment.
- Add the room-temperature butter, vanilla, and mix until it's all combined.
- Whip the buttercream on medium/high speed until it is white, fluffy, and doesn't taste buttery, this can take 8-10 minutes. Pro-Tip: To counteract the yellow in your buttercream, add a drop or two of violet food color gel to make it whiter.
- Switch to a paddle attachment and mix it on low speed for 15-20 minutes to make the buttercream very smooth and remove air bubbles. This isn't required, but if you want really creamy frosting, you do not want to skip it!
- This recipe is enough to frost and fill a two-layer 8" x 2" cake, or frost about 24 cupcakes. Store any leftovers in an airtight container in the fridge for 1 week, or freeze for up to 6 months.
Video
Notes
- Bring all your unsalted butter to room temperature.
- Use a scale to weigh your ingredients (including liquids) unless otherwise instructed (Tablespoons, teaspoons, pinch etc). Metric measurements are available in the recipe card. Scaled ingredients are much more accurate than using cups and help ensure the success of your recipe.
- Practice Mise en Place (everything in it's place). Measure out your ingredients ahead of time and have them ready before you start mixing to reduce the chances of accidentally leaving something out.
- Chill your cakes or whatever you are decorating with your buttercream before you begin frosting and filling.
- Making this buttercream is not hard, but it can be time-consuming. This buttercream requires heating egg whites with sugar over a double boiler until the sugar dissolves, and then whipping the egg whites into a meringue (and then whipping it into butter). If you want an easier recipe that skips heating the egg whites, check out my mock SMBC recipe for easy buttercream.
Sreeja says
Loved how the whole thing came together.
Just wanted to check will eggs be pasteurised at 110f? Because I see every other place saying 160f. I made my first batch and now contemplating about the egg safety. Please help
Elizabeth Marek says
110 is ok
ANA ORTIZ says
Hi!! Thanks for the recipe! I have a question! Can I use pasteurized egg whites to make SMBC?
Thank you🌸
Sugar Geek Show says
Hi! You can if you'd like, I know people do it all the time. However, I prefer to use raw egg whites because I've never been able to get pasteurized egg whites to whip into a strong enough meringue.
Jennifer says
Oh my God. I love you. I have struggled with SMB. And one try of this and it was excellent. I use all your recipes for my new cake business and you have been a blessing. Thank you💋
Suzy says
Shouldn’t you heat egg whites to 140f to pasteurize?
Elizabeth Marek says
The eggs are already pasteurized when you buy them, the heating is only to melt the sugar.