Recipe and Picture Tutorial: Swiss Meringue Buttercream Icing

Peggy Does Cake presents…
SMBC (Swiss Meringue Buttercream)

(Click any photo for an enlarged, “close-up” view.)

The first time I ever tried SMBC, I couldn’t figure out what the big deal was. To me, it was a mouthful of gently sweetened butter. It didn’t taste like icing. It tasted, and worse, it FELT, like butter. Constantly hearing from my cakey bakey friends that it was earth shatteringly delicious, I was sure I was missing something.
Then a brilliant cake friend of mine shared with me that the traditional structure of SMBC (which calls for 1 part egg whites, 2 parts sugar, and 3 parts butter) was too buttery for her, too. Tweaking the recipe down to only 2 parts butter was the perfect remedy. This icing has completely revolutionized my kitchen and I can’t believe I was living in a world without it for 45 years. Ok, I exaggerate, as I’ve only been baking for just under two years. Still, I can’t believe I was living in a world without SMBC for 2 years even! With a few little tweaks to the more traditional recipes you’ve probably seen and tried, you COULD become a believer, and this icing could rock your world.
  • Pan of shallow hot water, simmering with no visible “boiling” air bubbles
  • Your Kitchen Aid mixing bowl, clean and oil free
  • Spatula, clean and oil free
  • Candy thermometer
  • Digital Kitchen Scale
  • 8 large egg whites (or cheat like me and use them straight from the carton) – about 250 grams
  • 500 grams sugar (granulated sugar, confectioner’s sugar, or a combination of both)
  • About 6 sticks (690 grams) of cool butter, chopped into tablespoon-ish sized pieces (5 sticks unsalted, 1 stick salted)
  • 1 tablespoon best quality vanilla extract

When I begin making SMBC, I take my butter cold, from the fridge, and let it sit out while I cook my egg whites and sugar. As they cook, I unwrap the butter and chop it into tablespoon(ish) sized pieces. By the time the sugar mixture is ready, the butter is about the right softness: softened a bit, but still cool.

Always start SMBC right in your Kitchen Aid bowl – but make sure it’s perfectly clean and oil free or your icing could fail. Wipe your bowl clean with a paper towel or a cloth dampened with vinegar or lemon juice to ensure it’s squeaky clean.
Note: As long as your ratios are 1/2/2-ish, you can make any amount of SMBC you want. When I first began making it, I was always more comfortable making small batches, so this recipe is written as such. Just know that you can begin with any amount of egg whites – as long as you keep your ratios in tact.

Add 250 grams of egg whites to your mixing bowl (whether you’re using egg whites from a carton or using 8 large eggs, when you’re learning, you should always weigh your ingredients until you get the hang of this). I still weigh mine, just for thrills. If you don’t have a kitchen scale, get one. I happen to have this one from Ozeri and LOVE it. If using real eggs, reserve the yolks for another use.

Pour your weighed sugar into your KA mixing bowl with the egg whites and whisk together. Simmer whisked mixture over a pan of hot water. Do NOT let water boil, as you don’t want to cook the eggs. Make sure that your mixing bowl is NOT touching the water. You want to use the steam from the hot water to heat your pan. Use a candy thermometer and cook, whisking regularly, until the temperature reaches 150°. This is hot enough to make the eggs safe for consumption and will melt the sugar. At 150° the sugar should be completely dissolved and if you test it by rubbing it between your pointer and thumb, you should NOT feel any sugar grain. Once you’ve reached 150°, move the mixing bowl back to your Kitchen Aid and using the whisk attachment, whisk on medium for about 2 minutes. After the first 2 minutes, turn your mixer to high and let it run for about 7 minutes. Before you know it, you’ll have yourself a bowlful of the most gorgeous meringue you’ve ever seen.
But you’re not ready to make icing yet. (Although at this point you could use the meringue for other recipes that call for meringue…) Next, you’ll turn down your mixer to low and mix until the meringue is cool enough so that it won’t melt the butter when it’s added.
 This will take another five minutes or so, until the mixing bowl, when touched with the palm of your hand, has become neutral to the touch and is no longer warm.  You can’t tell that it’s no longer too warm by looking, but here’s the meringue, room temperature, and finally ready for the butter!

Once your meringue is perfect and no longer warm, swap to the paddle attachment and turn your mixer back to medium speed. Drop in the cool butter pieces one at a time until incorporated, moving quickly. I just toss them in one after another, as fast as I can go really. Mix on high until you reach a silky smooth texture. This has taken me anywhere from three (3) to eight (8) minutes. If your icing curdles or looks soft and gooey, keep mixing and it will come together.  Here’s a picture of my icing BEFORE it’s ready.  See how it’s grainy and won’t hold onto the paddle blade?

One of the coolest things about SMBC is that you can actually “hear” when it’s ready. The mixer changes pitch and takes on a noticeable, pleasant slapping sound. You can’t miss it if you’re listening for it. Here’s the same batch about 4 minutes later, now ready. See the paddle blade? And see how thick and full the icing is on my spoon compared to the photo above where it’s looking a bit flat and limp?

Once your icing is lush and perfectly smooth, you can add your extracts or other flavorings. Be careful to only add room temperature liquids though. (Ask me how I know…) If you’re adding, for example, fresh strawberries or strawberry puree, you definitely do NOT want to add them unless they are room temp. Cold additives to your SMBC will cause the butter to curdle and separate. As long as your flavor additives are room temperature, you can add just about anything:  preserves, nutella, chocolate ganache, tempered chocolate, caramel, peanut butter, etc. The sky is the limit.

If your buttercream is too runny, your butter may not have been cold enough. Place the entire KA bowl in the fridge for about ½ an hour and then try beating it on high again. If it’s still too soft or runny, add more butter a few pieces at a time, continuing to mix on high, until it comes together. Icing is ready to use immediately, but keeps well in the fridge for several weeks and freezes beautifully!  No more wasted icing!If you haven’t tried SMBC yet, I hope you will. It’s so easy, so fast, totally mess-free, and the taste is utterly and completely amazing!  Let me hear from you!

Oven’s on – I’ll be back soon!

~ Peggy

50 thoughts on “Recipe and Picture Tutorial: Swiss Meringue Buttercream Icing

  1. I’m definitely going to try this but I don’t have a freestanding mixer. Does it work with a hand whisk and beaters?

    • I think you could, sure. You might get VERY tired. The process takes quite a while – but it’s super easy with a stand mixer b/c you can set your timer and walk away. You’d be stuck there holding your mixer. Not sure that’s something you would want to do!

    • I have never needed a pure white, so it’s never been an issue for me. I know Americolor makes a white gel paste food color that’s meant to be able to “brighten” up white icing. You could give it a shot? If I have any luck with that, I’ll try to remember to create a post on here or Facebook!

    • At some health food stores, bake shops, or farmers’ markets, you can get butter that has not been dyed. This will give you a much brighter color. It’s still not going to be stark white, but very close.

  2. This may be a silly question, but how do you put the KA bowl over the simmering water? Is it resting on something above the pot with the water?

    • Allison, the official answer is that you “can” – but the taste will suffer. Not sure why you would want to. For stability? If so, I have mixed ABC and SMBC with great results (both taste-wise and stability-wise). I would do that before I would use shortening. Butter is THE key component here, so if you feel you MUST make a substitution, I would do it in very slight proportions – maybe 25 shortening/75 butter. If that didn’t suit your purpose, you could tweak it up with each batch until you find your taste threshold, but I wouldn’t go more than 50/50 and I’d add extra vanilla to compensate for the lack of flavor in the shortening.

      I’m probably the wrong person to ask this question to – as I despise shortening in icing. The taste and concept is disgusting to me. I’ve done a quick Google search and found there is a LOT of information “out there” about this, so you won’t have any trouble finding what you need.

      Let us know how it works if you try it, will you? We’re curious!


    • The chocolate is THE BEST. And I don’t even care for strawberry flavored stuff – but cover fresh chopped strawberries with sugar and infuse them, juice and all, and OMG. To. die. for. (Thanks to my friend, Lesley, of Royal Bakery, for encouraging me to try that recipe.) ~ Peggy

  3. I love this icing!
    what I do though is place the sugar and egg whites in another stainless steel bowl and then pour into my kitchen aid bowl, speeds up the cooling process by a few minutes.

  4. I failed! It looked ok until I added room temp cherry flavoring…the oil kind. Do u think that’s what made my soupy mess? I put it in fridge and then re-whipped but not much better. Tastes great but slides off my cake! 🙁

    • Cynthia, how much cherry flavoring did you add? Oil flavors take literally just a drop. I can’t begin to imagine how that could have changed the texture… Also, can you tell me what your ratios were on each ingredient by weight?

    • At first I wondered if you were joking around hehe! The directions above say “Do NOT let water boil, as you don’t want to cook the eggs. 150° is hot enough to make the eggs safe for consumption and will melt the sugar.” It has to be 150°F, as 150°C would completely solidify (scramble) the eggs!

  5. do u think there is much of a taste difference between Italian meringue bc and smbc? thats what i usually use and it is yummo maybe a little buttery but not that bad its a ratio of 1:1:2 and i use water to dissolve the sugar at 250F degrees but hey i really want to try this.

    • Tricia, I’m so sorry. I wasn’t getting my blog notifications and I missed your comment. I wonder if you ever tried it and if so, if it worked for you? SMBC does NOT crust.

  6. thank you for bringing it to my attention that I could bring the ratio down to one part butter haha

    I’m in a culinary degree for pastry and baking specifically. but you know chefs are all about doing things the traditional way, for whatever reason. so we’ve always been told the traditional ratio and nothing else, and we use it for many cakes. but to me, all the butter absolutely ruins the cake for me, noting worse than biting into something, enjoying the flavor of the cake, then hitting a slab of bland mush. HAHA

    I’ll be trying out this recipe very soon 🙂

  7. I’m a smbc lover, and feel my current recipe is on the buttery side, It still gets the wow factor on my cupcakes and pipes lovely on those but have never used it to fill…for the fear of the high fat content and our aussie heat…! so I’m going to try your recipe lesly from Royal bakery sent me here, and I’m so glad she did….loving your informative..

    • Yes you can! The best thing to do is to take it out of the fridge long enough for it to come back to room temp and then re-whip it until it comes back to a good consistency.

  8. Hello, I was wondering what adding a salted stick of butter does for taste? Do you taste the salt at all? What brand of butter do you recommend?

    • I think it adds just a bite of salt, but you can’t use salted butter all the way or the icing tastes too much like butter. Just try it and use whatever your taste calls for.

  9. I have tried smb before (some else’s recipe) but similar to yours and mine was a bit runny. I tried keeping it in the fridge and added butter and whipped it too but no luck.
    I warmed my egg whites to 160F and then whipped it up but after about 1/2 of whipping the bowl still wasn’t neutral to touch. I thought I would dry the egg whites out and started to add the butter.
    My question is what if the bowl still feels warm to the touch, do I keep the whole bowl in the refrigerator until it cools or just keep on whipping the egg whites/sugar mixture until it cools off. Please help because I really want to try this again.

    • Asmita, I’ve emailed you, but I’ll post a couple quick ideas here for others, as well. Heat eggs to 150, not 160. That will help. (Just do the finger test to be sure the sugar is melted thoroughly.) Try warming the eggwhites/sugar in a pan and then transferring it to your mixing bowl (I don’t do this, but it could help). Make sure your meringue is not too warm before you add your chilled butter. It’s normal for the meringue to soften the butter as you drop it in, but it shouldn’t completely melt it into liquid. Your “icing” will be very soupy/sloppy sounding at first – but it should come together quite quickly into a lush, super-thick icing. It’s true you can chill the mixing bowl at any time to help cool the icing, and often that helps it bind together, but you must make sure you’ve started everything off perfectly first. This is such an easy recipe, I hope you’ll give it another go. Once you get it right, you’ll LOVE it!
      ~ Peggy

    • Hi Peggy,
      I have been looking for a good buttercream recipe since a long time since I hate the traditional sweet icing . I like the texture of the regular SMBC but it suffers the taste. I found your site and thought of trying your SMBC. I must say that I just loved it. It is so silky to work with and taste awesome. Not at all sweet and buttery. Its a keeper. Thank you so much for sharing.

  10. Hi Peggy
    Thanks so such for sharing this recipe.
    I’ve always been a believer in the good old butter icing but have had a lot of problems lately due to the heat. ( 28 – 40 degrees Celsius ) It melts and my cupcakes are a mess.
    I’ve heard from a supplier that the bakers in area are using the swiss butter cream but have been weary of using a you tube recipe.
    Could I ask your advice on the resistance to heat issues – how does this butter cream hold – ( still contains butter so surely it melts – does it have to be kept in fridge?
    Can I ice my cupcakes 2 day prior to selling and place in fridge and then leave out for 4 -5 hours without having a melt down?
    Please advise, i’m so lost – clients love my cupcakes but tell me I need a solution for them to be able to leave them out a few hours
    Thanking you in advance

  11. Hi Peggy, I have done SMBC before but I must say your recipe is so light and fluffy it is wonderful. I love the flavor and the not so greasy after taste. I do have a question, can this SMBC be used to ice the cake before applying fondant? thank you in advance to your response.

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