Swiss Meringue Buttercream Frosting

While I frost most of my cakes with American buttercream, sometimes I like to mix things up! One of my resolutions this year was to be more open to different types of frosting, and I’ve stuck to it! After a bit of trial and error, I feel like I have finally mastered Swiss meringue buttercream frosting (SMBC).

This type of frosting definitely takes a bit more effort and time than my American buttercream, but it isn’t as difficult to make as you might think.

It also is a bit more stable, and less finicky once it’s made! My favorite thing about swiss meringue is that it doesn’t crust. You don’t have to cover it with plastic wrap, or worry about your frosting crusting on your cake if you make it in advance.

image of siwss meringue buttercream being made in a kitchen aid stand mixer

After what feels like a zillion batches, I found that I prefer mine with a bit more salt and slightly less butter than most SMBC recipes call for.

While half the battle of SMBC is having a good recipe, the other half is how you make it! That’s why I’m also walking through everything you need to know to make the smoothest, fluffiest swiss meringue buttercream frosting in this post.

Step #1: Room Temp Egg Whites

What gives this frosting its incredible texture is the meringue that it’s made with. That’s why the eggs in this recipe are so important. Or more specifically the egg whites!

If you’re not quite sure what to do with the 7 egg yolks you’ll be left with after making this frosting, here’s a great post with loads of ideas for using up leftover egg yolks.

You want to make sure your egg whites are at room temperature when you make this frosting. Room temperature egg whites whip up better and faster than egg whites that are cold.

image of meringue made on a whisk attachment for swiss meringue frosting

I suggest separating your eggs about an hour before you plan to make your frosting. Be careful as you do this, because they won’t whip up properly if any yolk gets into the mixture!

If you forget to take your eggs out of the fridge, you can always pop them into a bowl of warm water for 5 minutes to quickly bring them to room temperature.

Normally I’m a huge fan of using egg whites out of a carton, but that’s when I’m adding them into a batter. When it comes to making meringue, I find that carton egg whites simply don’t whip up as well.

I really struggle getting stiff peaks with them. I’m not sure if the pasteurization process does something to the protein in the egg or what, but I don’t recommend using egg whites from a carton to make swiss meringue frosting.

Step #2: Making The Egg Whites Safe to Eat & Knowing When The Mixture is Hot Enough

There’s something about the idea of adding raw eggs into frosting that seems a bit creepy. A lot of people worry it isn’t safe to eat, but we take an important step to ensure it is!

By heating up our egg whites and granulated sugar with a double boiler to 160 degree Fahrenheit, we accomplish two things at once.

The first is that we kill any potentially harmful bacteria. Salmonella is instantly killed at temperatures above 160 degrees F.

The easiest way to ensure your mixture gets hot enough is to use a digital thermometer. This helps you know exactly when your egg whites are warm enough, and prevents you from overheating them.

If you don’t have a digital thermometer on hand, you can test with your finger. The mixture should be quite warm to the touch, but not hot enough to hurt or burn your finger.

The second thing we accomplish is dissolving the granulated sugar, which gives the frosting a silky smooth texture.

It’s very important that the sugar is fully dissolved before you make your meringue, or else your frosting can end up with a grainy texture.

A great way to know your mixture it ready if you don’t have a thermometer is the finger test! Take a tiny bit of the warm liquid between your forefinger and thumb, and rub them together.

image of testing meringue base with fingers to make sure the sugar is fully dissolved before making it into swiss meringue buttercream

The mixture should be smooth, and you shouldn’t be able to feel any sugar granules. If you do, I suggest heating your egg white/sugar mixture a bit longer then testing again to make sure it’s smooth.

Step #3: Making Stiff Peaks

Once your sugar is fully dissolved and your mixture is smooth, it’s time to whip it into a meringue with stiff peaks. This takes quite a bit of time!

I find it takes me about 10 minutes of mixing with a whisk attachment on a medium high speed.

You could in theory make this swiss meringue frosting with a hand mixer, but it would take forever!! Making it with a stand mixer is much easier and quicker.

Stiff peaks should look like my whisk below, where the meringue can stand up on its own when flipped upside down.

image of meringue made on a whisk attachment

It can be hard to tell when the meringue reaches this stage just by looking at your mixing bowl, so feel free to take breaks and test it by removing your whisk attachment.

Doing so won’t have a negative impact on your meringue. It just helps make sure you get the consistency just right without over mixing your meringue.

Step #4: When and How to Add in Your Butter

Once your meringue has stiff peaks, it’s time to mix in the unsalted butter.

After all that mixing you’d think your bowl would have fully cooled off, right? But you might be wrong! At this point in time I like to feel that bottom of my bowl with my hand.

If it feels pretty much room temperature, I add in my butter. If it still feels warm, I’ll either wait another 15 minutes to add the butter or pop my bowl into my fridge for 5 minutes to help it cool down.

Usually by making sure your meringue and bowl have cooled to room temperature, you can prevent your swiss meringue buttercream frosting from becoming too thin or soupy.

image of swiss meringue frosting

When I do start to add in my unsalted butter, I do it in small chunks (about 1 Tbsp at a time). This gives your meringue time to incorporate the butter, and helps it mix together more easily.

As you add your butter, it’s super important that your butter is room temperature. This does NOT mean soft to the touch, or greasy.

Most sticks of butter come to room temp in about an hour, so be sure your butter doesn’t sit out much longer than that or it may become too soft.

It should be soft enough for you to be able to press your finger into, but firm enough that you have to apply a bit of pressure to do so.

Step #5: The Attachment Switcheroo

When all your butter is mixed in and you’ve added in your salt and vanilla, it’s time to swap out your whisk attachment!!

While we want our buttercream to be fluffy and light in texture, we also want it to be smooth.

Whether you plan to spread your frosting onto a cake or pipe with it, your frosting needs to be smooth and air bubble free.

I find that mixing your finished frosting on a low speed with a paddle attachment for a few minutes makes a world of a difference.

This makes it way easier to smooth onto cakes!!

Troubleshooting

Two of the most common issues people run into when this type of frosting are curdled or soupy frosting.

While it might seem terrifying to watch your frosting seem to fall apart, fear not. Both problems are actually pretty easy to fix!!

How to Fix Curdled / Broken Swiss Meringue Buttercream

A lot of different things can cause your SMBC to break or curdle.

Maybe your butter was too cold, or your kitchen was too chilly. Maybe you were thawing a batch of buttercream made in advance, and it hadn’t fully come to room temperature before you started mixing it.

image of adding butter gradually into swiss meringue buttercream frosting

Whatever the reason, your frosting looks chunky, dense, and greasy.

But don’t worry, your frosting isn’t ruined! There’s an easy work around that will bring your frosting back together.

Simply place your bowl over a hot water bath / double boiler until the frosting around the edge of the bowl has melted. Then give it a good mix for several minutes.

The melted, warm frosting around the edge of the bowl will mix with the frosting that’s too cold. This will bring the overall temperature of your frosting up to the right temperature and allow it to become smooth again.

How to Fix Soupy Swiss Meringue Buttercream

On the other hand, if your frosting is too warm it might become a soupy, runny mess. This can happen if your meringue is too warm when you add your butter, if your butter is too warm, or if your kitchen is too toasty!!

If your frosting isn’t sturdy enough to keep its shape, you need to cool it down. To do this, just pop your mixing bowl and whisk right into the fridge.

I like to chill my bowl for about 20 minutes. At this point the center might still be a bit soupy, but the frosting along the sides of the bowl should be firmer. I mix it for a few minutes to see if it comes together.

If after 3-4 minutes of mixing it still looks too soft, I chill the bowl for another 10 minutes before mixing it again. That usually does the trick!

Coloring Your Swiss Meringue Buttercream Frosting

The last thing I want to touch on is coloring swiss meringue buttercream frosting.

This type of frosting is a bit more difficult to color than American buttercream. To make it bright and colorful, gel food coloring is a must.

My favorite gel food coloring is Americolor, and it’s the only food coloring I use. 

image of spring easter cake being decorated with swiss meringue buttercream flowers

Even with gel food coloring, I find I have to use quite a bit to get my colors really vibrant.

If you want make deep or really intense colors, I highly recommend making your frosting in advance. The color of the frosting will deepen overtime!

Tips For Making Best Swiss Meringue Buttercream Frosting:

  • Traces of grease in your mixing bowl can prevent your meringue from forming stiff peaks. You can wipe down your tools with lemon juice or vinegar to make sure they’re grease-free.
  • Use room temperature egg whites; they whip up more quickly and easily than cold egg whites
  • Heat your egg white / sugar mixture to 160 degrees F and check to make sure all the sugar is dissolved
  • Whip your meringue until your peaks are stiff enough to defy gravity
  • Make sure your butter is actually at room temp, and add it in slowly (1 Tbsp at a time)
  • When in doubt (if your frosting breaks / curdles), just keep mixing!! It should come back together with the help of your stand mixer
  • Mix your finished buttercream on the lowest speed with a paddle attachment for a few minutes to make it smooth
  • 1 batch of frosting is enough to fill and frost a seven or eight inch layer cake.

Making This Swiss Meringue Frosting in Advance and Storage Tips:

  • Make your frosting ahead of time or save any leftover frosting! It can be stored in an airtight container at room temperature for 1-2 days, in the fridge for up to a week, or in the freezer for up to 3 months.
  • Be sure to give it a good stir once it thaws to room temp to get the consistency nice and smooth again.
  • A frosted cake can last in the fridge for up to a week, or in the freezer for up to a month. The buttercream locks in all the moisture, keeping the cake fresh and delicious!
  • If you cut into the cake and have leftovers, use any remaining frosting to cover the cut section to keep it moist and store in the fridge for up to a week.
image of cake frosted with fluffy faux swiss meringue buttercream

Let Me Know What You Think of This Swiss Meringue Buttercream Frosting!

If you try this recipe for swiss meringue buttercream frosting, I’d love to hear what think of it! Please leave a rating, and let me know your thoughts by sharing a comment 🙂

Also please tag me @chelsweets, and use the #chelsweets so that I can see your amazing creations on social media!

Yield: 6

Swiss Meringue Buttercream Frosting

image of siwss meringue buttercream being made in a kitchen aid stand mixer

This swiss meringue buttercream is made with fluffy meringue, and has the perfect balance of sweetness and richness!

Prep Time 30 minutes
Cook Time 5 minutes
Total Time 35 minutes

Ingredients

  • 7 large egg whites (235 grams)
  • 2 cups granulated sugar (400 grams)
  • 2 cups unsalted butter, room temperature (454 grams)
  • 1/4 tsp salt (1 gram)
  • 2 tsp vanilla extract (8 grams)
  • gel food coloring (if desired)

Instructions

  1. In a medium sized pot, add about 1 inch of water bring to a simmer.
  2. Before making the frosting, be sure to thorough clean your mixing bowl; if there’s any grease it can make it difficult to make the meringue.
  3. Add the egg whites and granulated sugar into your clean mixing bowl.
  4. Place the bowl on top of the pot filled with simmering water, being sure the water isn’t actually touching the bottom of your bowl. The bowl should create a seal over the pot.
  5. Whisk the mixture constantly for about 3 minutes, until it reaches 160 degrees F. You can test the mixture to see if it’s ready by rubbing a tiny bit between your fingertips. The sugar should be fully dissolved, and it should feel super smooth and hot to the touch.
  6. Lift your bowl away from the pot, and dry the bottom with a towel.
  7. Lock the bowl into place on your stand mixer, and beat on medium high using a whisk attachment. Mix for about 10 minutes, until you have stiff and glossy peaks.
  8. At this point in time, the bowl should be back to room temperature and no longer warm to the touch. If it’s warm, it will melt your butter!!
  9. Once bowl is at room temp, swap out your whisk attachment for your paddle attachment.
  10. Mix on a medium speed and add in the unsalted butter, 1 Tbsp at a time.
  11. Add in the salt, vanilla extract and purple gel food coloring (if desired) and mix on a low speed until fully incorporated.
  12. When all butter is mixed in, scrape the sides and bottom of the bowl with a rubber spatula and continue mixing for about 3 minutes.
  13. The frosting should have a thick whipped consistency at this point. If it looks lumpy or broken, keep mixing until it looks smooth and thick.

Notes

One batch is enough to fill and frost a 7 or 8" layer cake, or enough to frost three dozen cupcakes.

Make your frosting ahead of time or save any leftover frosting! It can be left out at room temperature for 1-2 days, stored in an airtight container in the fridge for up to a week, or in the freezer for up to 3 months. Be sure to give it a good stir once it thaws to get the consistency nice and smooth again.

A frosted cake can last in the fridge for up to a week, or in the freezer for up to a month. The buttercream locks in all the moisture, keeping the cake fresh and delicious!

If you cut into the cake and have leftovers, use any remaining frosting to cover the cut section to keep it moist and store in the fridge for up to a week.

Nutrition Information

Yield

6

Serving Size

1

Amount Per Serving Calories 825Total Fat 61gSaturated Fat 38gTrans Fat 0gUnsaturated Fat 20gCholesterol 163mgSodium 170mgCarbohydrates 67gFiber 0gSugar 67gProtein 5g

62 thoughts on “Swiss Meringue Buttercream Frosting

  1. Hi Chelsea! I was wondering can i add more flavour to this frosting, Like caramel or peanut butter or both as i was thinking of making your snickers cake but instead of American buttercream use this SMBC

    1. Hi Dina,

      You can totally add in other flavors into this frosting!! Adding in PB or caramel would taste amazing 🙂 I’d recommend adding them in after you’ve mixed in the butter. Hope that helps, happy baking!

    1. Hi Elizabeth,

      So sorry to hear that, hopefully we’ll be able to troubleshoot together. When you say you couldn’t get it smooth, do you mean it was curdled? or it had air bubbles in it?

    1. Hi Aaryah,

      You totally can! This swiss meringue buttercream is wonderful for filling and frosting cakes 🙂 Happy baking!

    1. Hi Teresa,

      They should stick if the cake is slightly chilled! This frosting doesn’t crust like ABC though, so it won’t be quite as locked in place as that.

  2. Thank you so much for your thorough instructions and great recipe! It turned out perfect in my first attempt. I used it for frosting on your small batch funfetti cake recipe! I am so excited! Thank you!:)

    1. Hi Stanciu,

      You can use liquid coloring, but it won’t give you a very vibrant color! You also have to be careful how much you add! If you add too much liquid into the frosting, it can break :/

  3. Is there a big different in taste/texture between this recipe and the “faux” Swiss meringue from the matcha cake? Mainly wondering because I have an entire carton of pasteurized egg whites and trying to decide which recipe to use.

    1. Hi Meg,

      There is a slight difference in the taste and texture, but not much! The faux swiss meringue is also a lot easier to make 🙂

  4. Hi Chelsey!
    I’ve been following you on YouTube for a couple of weeks now but I haven’t tried any of your recipes yet. I’m making a cake and would like to try this Swiss Meringue buttercream to frost the cake with but I would want to add fondant cutouts to it. I don’t have much experience with cake decorating yet so I am not sure if the fondant cutouts will stay on this buttercream or your American buttercream. Please help! Thank you so much I’m advance.

    1. Hi Annabel,

      It depends on what size your cut outs are! If you chill a swiss meringue buttercream cake, fondant cut outs should stay in place with a little extra frosting, but my american buttercream does chill firmer and crust, which really keeps things in place. Hope that helps, and that your cake turns out great <3

  5. Hi. I was wondering why your recommend the egg whites to be at room temperature, since we don’t actually whip the meringue until after the double boiler. So they will be hot at that point. I have never let them get to room temperature, and have never had issues with them whipping nicely. Just a thought.

    1. Hi Val,

      That’s actually a great point! I guess the temp of the eggs isn’t that important since they will be heated on the double boiler!!

  6. Hermosa receta, quiero hacerla pero tengo batidora de mano, entonces no tiene accesorio de pala, cómo podría hacerla??
    Otra duda es, se puede usar margarina??

  7. Hi, thanks so much for this recipe I love it! But can I double this recipe like use 14 eggs and 4 cups of sugar and 2 cups of butter instead of the recipe listed????? Just don’t want to have to make 2 batches at different times making a bigger cake.

    1. Hi Savannah,

      Unless you have a commercial sized kitchen aid, I wouldn’t recommend it! You need a lot of space in the mixing bowl to properly whip your meringue and it’s really hard on your mixer! Sadly I’d suggest making two separate batches :/ It’s more work, but will ensure both batches turn out great and you don’t overwork your mixer!

  8. Hello, I’ve been trying this recipe and everything goes good till I add the butter, I have tried to put it on the fridge but still does not work ? I have tried a couple of times and everything goes wrong as soon as I add the first spoon of butter I even tried to start by adding 1/2 spoon of butter but still does not work (I did check the bowl temperature and was not hot at all also the butter was not soft to the touch or greasy.
    Thank you for your time!!

    1. Hi Angeles,

      I’m so sorry to hear that! It’s hard to know without being able to see how you make it :/ It sounds like you’re doing all the right things though. What do you mean when you say it goes wrong? Is your frosting soupy, or broken?

      I’d suggest maybe trying a different type of butter?? That’s the only thing I can really think of if you’re following all the directions to a T. Sorry I can’t be of more help!

  9. I tried this recipe for a small batch and I noticed that the buttercream had little droplets of water and even when piping, the liquid kept squirting out, where did it possibly go wrong?

    1. Hi Oluwatomi,

      When you say droplets, I think you mean that your buttercream had separated! That can happen when the butter in your frosting is too cold. I’d let the buttercream sit out at room temperature for about 30 minutes, then try mixing it again until it’s smooth.

  10. Will it be an issue if I don’t have a whisk attachment for the mixer and just the paddle? Would I need to hand whisk it?

    1. Hi Julia,

      Sadly it will be an issue for this recipe. You need to be able to whip up a meringue with stiff peaks, and to do that you really need a whisk attachment :/ You could try doing that with an electric hand mixer, but I think it’ll take quite a while!

  11. Thank you for the great recipe.
    I noticed that in the steps, you mentioned that the whisk attachment should be replaced by the paddle attachment BEFORE adding the butter, but in the video, you added the butter while you are still using the whisk attachment.
    I know that paddle attachment should be used at the very end just to smooth out the cream as you mentioned in the video, is that right?
    Your fan from Kuwait: Safa

    1. Aw thanks Safa!

      I’ve made it both ways, and both ways work just fine! The key thing is just that you the whisk attachment to whip up your meringue. I think it’s best doing it at the end, but it’s your call! Sorry if that inconsistency caused any confusion <3

  12. Thank you for replying!
    I have tried the recipe and it was amazing. Couple of questions though..
    1. Can the recipe be halved?
    2. Can I use the “pre butter adding” phase as marshmallow fluff? Coz it tastes sooo good ?

    Safa

    1. Hi Safa,

      You can definitely halve this recipe 🙂 And for can use this frosting without butter / just as a yummy meringue! Happy baking!!

  13. Made this many times and I always have air bubbles or it’s just slightly “bumpy”. It’s not broken or curdled. The sugar was melted too… not grainy just not super soft and smooth when spreading….. any ideas?!

    1. Hi Sharon,

      My only suggestion is to give it a really good stir with a rubber spatula. Really work the frosting back and forth to try to push out any excess air. Doing this for a couple minutes usually smooths out my frosting, I hope it helps you too! <3

  14. I want to make your white chocolate raspberry cake with this filling instead of the american buttercream. Do you think adding white chocolate to this SMBC will turn out tasty and stable enough to stack the cake? (For the outside i am going to use the american buttercream as i need it to crust for decorating…)

    1. Hi Divy

      For sure! SMBC is very stable. Just be sure to add the raspberry filling first, as it’s quite thick and would be hard to spread on top of this frosting. Hope your cake turns out wonderfully <3

    1. Hi Vicky,

      For sure! Beat 8 ounces of pure melted and slightly cooled chocolate into the buttercream when you add the vanilla and salt. Make sure you’re using pure baking chocolate (the 4 ounce bars) like Baker’s or Ghirardelli brands found in the baking aisle.

  15. I tried making this and i had the stiff glossy peaks my bowl wasn’t warm anymore but once i added my butter it wouldn’t come back together and get fluffy again. Not sure what i did wrong?

    1. Hi Ericka,

      It’s hard to know without being able to see your bowl! Was the frosting separated? Or chunky? Is there a chance your frosting was too cold??

  16. hi chelsweets!

    is it okay to halve the recipe and to use less butter than the recipe actually says?

    hoping you would see this ?

    1. Hi Sarah,

      You can halve this recipe, and adding a bit less butter should be ok. You’re basically just making a meringue by using less butter, but that should work ok! It will be a bit less silky/rich, but should still work as long as you use some butter!

  17. It was so soupy ?It did end up coming together after 15 minutes of mixing but it still wasn’t as fluffy as yours ? but I’m going try again

    1. Hi Ericka,

      If it’s soupy it’s usually because the meringue or your bowl were still a bit too warm when you added in the butter. Hope that helps, and that your next batch turns out great <3

  18. Hey chelsey ! I wanted to use this buttercream for your 6 inch small batch chocolate cake. If I half this recipe, will it still be enough to fill and frost the cake ? Thanks in advance 🙂

  19. When do you swap your whisk for the paddle? In your blog description Part you say after the butter but in the Step by step actual recipe you say before the butter?

  20. Hello Chelsey
    I’m planning to make a naked cake ( 2- 6” layers ) and want to use SMBC to frost it on the outside only
    Can I half the recipe?

  21. Hello Chelsey!

    I tried your recipe my first time trying SMBC and I have a question about the flavor. Is it suppose to taste a lot like butter because mine did. The consistency of the buttercream was perfect it just tasted a lot like butter and not like buttercream or sweet at all. What can I do to fix it in the future?

  22. Hi Chelsey!
    Can I use pasteurized egg whites and treat them just like regular egg whites to make this frosting. I mean they are pasteurized but I don’t know if I can simmer the egg whites and it will work ok. Thank you!

  23. I get a lot of requests for a frosting less sweet than BC so I am very interested in trying this for the first time! My concern is, does it pipe the same as regular BC? Hold its shape and color well? And does a cake decorated with SMBC need to stay refrigerated ? Thank you !!! Your recipes are my GO TO!! ???

  24. Hey! When making chocolate Swiss buttercream would you do cocoa powder or melted chocolate? Or does it matter?

Let me know what you think!