All About Swiss Meringue Buttercream

When I first started cake decorating, I didn’t know there were different types of buttercream. The only one I knew how to make was the traditional butter and icing sugar type of buttercream.

I am not sure when I actually first heard of swiss meringue buttercream (SMBC) but I remember reading all these people raving about it online. Saying how smooth, silky and yummy it was and I remember printing my very first recipe and trying it out with great anticipation… except I failed miserably. Mine looked nothing like the picture and resembled lumpy soup more than the nice silky, light buttercream I was promised!

So, for a long time I stayed away from SMBC. Preferring to only work with ganache or traditional buttercream. It wasn’t until I visited Mike McCarey a couple of years later that I discovered the real taste of SMBC and how it is possible to use it just like ganache (he used it for the 3D structural cakes we made in class).

So, again I went back and tried to tackle getting SMBC right. And after much research and trying I discovered that SMBC is actually much easier than I thought. A lot of people (myself included) panic when things go wrong during the process but I have since learnt all the things that go wrong basically boils down to two things: the mixture being too hot or too cold.

Below are some tips I have put together to hopefully help you get past of your fear of making SMBC. And I promise it does not have to be hard or complicated. I know some of you will get turned off from the extra step/s and processes but it’s worth it and it’s really not that much extra work. So give it a go!

A 3 tier buttercream cake with fondant accents.

Before we get started you should know the other types of buttercreams that are out there, what’s in them, and how they are different. Let me break it down for you or it can get confusing.

American Buttercream (ABC) – this typically does not have any actual butter in it and it’s vegetable fat based. The butter is substituted for fat (like Crisco) and mixed with icing sugar.

This results in a true white buttercream and depending on the ratio of icing sugar*, the buttercream will crust. This buttercream also has a higher melting point which is great if you have warm hands and want to pipe with it, live in a hot climate, or if the cake will be displayed outside.

Traditional Buttercream – this is made with just butter and icing sugar and is what most people are used to making. Depending on the ratio of icing sugar*, the buttercream will also crust.

Once I tasted SMBC, I found it hard to go back to this style of buttercream because I personally found it a little too grainy. Also, being butter based, you will find it quite difficult to get a true white finish. See the colouring tips section below for more information on how to offset the yellow colour.

* Icing sugar is different from icing mixture. I recommend using pure icing sugars for buttercreams because icing mixtures tend to have corn flour/starch in it which may alter the taste. It’s also important to get a good brand of icing sugar and sift it. I find the cheaper brands tend to create a grainier frosting and if you don’t sift it, you end up with lots of lumps!

Italian Meringue Buttercream (IMBC) – this is egg white based and made with the same ingredients as SMBC except the process of making it is different. The sugar is cooked with (or without, depending on the recipe) a little water until it reaches a certain temperature and becomes a thick syrup. The syrup is then added into the beaten egg whites. The hot sugar basically cooks the egg whites and some people say this is better because it makes the meringue more stable than SMBC before you add in the butter. I personally have not noticed a difference so my preference is for SMBC because it’s quicker to put together. Give both a try, you might find one works better for you or your climate.

French Buttercream – this is usually egg yolk based and a very rich buttercream used in French pastries. Because of the use of egg yolks, it needs to be refrigerated and does not have a very long shelf life so I would not recommend using this in cakes.

Now back to SMBC! I have put together a video so you can see how it’s made and I have also included the link to my recipe calculator so you can print out the recipe. I have seen some recipes floating around the internet where people are using icing sugar in the SMBC recipes instead of regular sugar and it seems to work well. I have not personally tried it, so I am not sure if the taste is different, although I don’t see why it won’t work.

The buttercream recipe can be found here and the amounts in the video will make enough for an 8 inch round cake.

Some Tips

The Ingredients

Ensure all your ingredients are at room temperature. You can soften butter in the microwave (in short bursts) and soak cold eggs in warm tap water for about 20 minutes if you don’t have time.

Caster sugar is just finely granulated white sugar. In some countries, you might not be able to buy this so you can either make your own (placing white sugar in a grinder) or you can just heat your egg whites and icing sugar over a pot of simmering water until the sugar has dissolved.

In some places, it is possible to just buy egg whites in a carton. This is usually found at bakery wholesalers, health food stores, or the health section at your supermarket. These carton egg whites are usually pasteurised so it’s safe for you to eat raw (it will mention it on the packaging) so if you use this and caster sugar you won’t need to heat the bowl over a pot of simmering water. If you use fresh egg whites, you should heat it over the bowl of simmering water.


Because of the butter, the colour of your SMBC will always a little yellow or off white. The intensity of the yellow will be dependent on the brand of butter you use (in some countries it is possible to get a ‘milk’ type butter which is actually white). It is possible to offset the yellow in the buttercream by adding a VERY small amount of violet colouring. This will neutralise the yellow and you will end up with a light ivory colour.

I have tried using white colouring and titanium dioxide but have found that it won’t work unless you use a lot and then it ends up affecting the taste of the buttercream.

Because of the yellow base, it is difficult to get true pastel colours. For example, light pinks will end up looking more like peach and light blues will end up looking more like turquoise. So, you need to keep this in mind when designing your cake. An option would be to use ABC for those colours instead.

When colouring dark colours, keep in mind that the buttercream will deepen in colour overnight. So colour, then allow it to set overnight before using it.


I tend to flavour my SMBC with fruit powders and essences (which you can get at speciality cooking stores). It is possible to use fresh fruit, purees and jams but I would advise to do it with caution as it will change the consistency and shelf life of the buttercream.


You can store SMBC in a closed container at room temperature (around 22 degrees Celsius) for a couple of days but if you live in a warmer country, you should keep it in the fridge or you can freeze it. Take it out and leave it on the bench a couple of hours or the night before you want to use it. Rewhip it with a mixer or by hand before using it. If it’s too cold (see troubleshooting section below), you will need to reheat it up over a puot of simmering water or in with a very quick burst in the microwave.


The finished SMBC should be light and easy to spread like you see at the end of the video.

Problem Possible Reason and Solution
Mixture looks like scrambled eggs and is curdling (liquid is separating) The ingredients might not have all been at room temperature and the mixture is too cold which has caused the butter to solidify before it could fully mix through. There are a couple of options here (all will achieve the same result):

Option 1 – Use a blow cooking torch to heat up the side of the mixing bowl while the mixer is on.

Option 2 – Place the mixing bowl over a pot of simmering water and mix the buttercream by hand until it starts melting a little. Then place it back into the mixer and mix it all together.

Option 3 – Take out about a quarter of the mixture and heat it up in the microwave in short bursts until it’s slightly runny. Then add it back into the mixing bowl and mix it all together.

Mixture is like soup Chances are, the mixture is too hot and the butter has melted. Place the whole bowl into the fridge for 10-15 minutes to cool down and then mix it again.

In some cases, if you know that your mixture is not hot (the side of the bowl is cold/cool, or you have already placed it into the fridge) it might be that the ratio is off. You might need to add a little more butter into the mixture to firm it up.

How To Use

I use SMBC the same way as ganache to set up my cake. The only difference is that I place my cake in the fridge between the crumb coat and final layer to firm up the buttercream. I also make sure to place the cake in the fridge for about 10-15 minutes before I cover it. This ensures the buttercream is firm and I can get sharp edges on my fondant.

Yes, the cake will sweat when you cover it with fondant. You’ll need to work quickly and then let the fondant sweat. It will disappear in about an hour.

If you want to learn more about how to set up your cake properly and flawlessly with ganache or buttercream, check out my cake decorating books or my tutorial – The Basics Bible.

18 thoughts on “All About Swiss Meringue Buttercream

    1. Hi Sharon, the sugar helps the meringue to set and stay stable so it might not work as well with less sugar, and the flavour balance will change. You can certainly try, a little less probably wouldn’t hurt but you will probably need to whip longer to create structure.

    1. Hi Hazel, as a general rule if butter cannot, then SMBC cannot. So it wouldn’t be very stable at all after so long for so hot, air conditioning is best. A shortening based (e.g. Crisco) recipe would be more stable but that’s still quite hot so I haven’t tested such weather myself yet.

  1. What a great resource. Thanks! What consistency should the SMBC be when you spread it on the cake, and once it’s set? Should it be light and fluffy when you put it on, and should it Harden/crust once i’s been iced?? I’ve made it before, and think it’s great, until I’ve put it on my cake and it’s been incredibly soft. On one occasion, it was a hot day, it literally kept running off the cake. I’ve also found it hard to get a smooth service, even when using the correct tools… I’ve read that it’s possibly my butter was too cold when I added it?

    1. Hi Emma, sorry it took a while to reply but there’s a lot to write about! When spreading it should be smooth like peanut butter or whipped cream, and shouldn’t crust or harden at room temperature. If you want it to harden you can put it in the fridge. If it’s too soft you can try our recipe if you haven’t. However since it’s mostly butter, in general if it’s hot enough for butter to be soft, the buttercream will be too. so it’s not the best for hot climates and a fat based (e.g. Crisco based) recipe might be better for you.

      If you have trouble getting a smooth surface make sure the buttercream is very smooth and easy to spread. If it’s too stiff some short bursts in the microwave can help fix it, just heat a little and mix it around. If it’s taking a while you can put the cake in the fridge for a little bit to take breaks as you work, so it doesn’t get too sloppy and melty from all the movement. Most important is the base cake should be cool and firm, and the buttercream has the correct spreadable consistency, and you can reliably get smooth results with some practice.

      Hope that helps!

  2. Hi there, I am wondering if I can refrigerate my frosted (with SMB) cake overnight? Or with this change he finish of the frosting?
    Thank you

    1. Hi Ashlea, sorry I missed this one! If it is just covered in buttercream it should be fine in the fridge, SMBC frosting doesn’t crust like some other buttercreams so it should stay the same. It’s important to keep it cool so it doesn’t melt, room temperature is usually fine but the fridge can work too.

  3. hi.many say the ratio is 1:2:2 for u think i can add some powder sugar so it will be less buttery taste?and be more stable and pipable?what do less egg whites do to the mixture or less butter do to mixture?thanks

    1. Hi Dimitra, some recipes mention 3:2:1 for butter:sugar:eggs and our recipe is very close to this ratio which is what I prefer to use for my cakes. It can be changed a bit for other uses but when covering with fondant it’s essential we ensure the buttercream is firm enough to get a good finish. If you are using it as a filling or just piped you could adjust the ratios a bit to experiment.

      More sugar will make the buttercream sweeter so that might work, reducing eggs will make it closer to American buttercream which is just butter and sugar. Reducing butter will change the structure and it won’t be as dense so that could be a problem if it needs to set firmly before being covered by fondant. It will be closer to a meringue the more butter you remove.

  4. Hi Sharon,

    Just wondering how much chocolate I would need to add to your SMBC recipe to make a nice chocolate SMBC?


    1. Hi Belinda, usually I just use cocoa powder instead of chocolate because it doesn’t affect the consistency much. I use around 4 heaped tablespoons but each brand might vary so I’d suggest tasting as you go. You can mix it in at the end.

    1. Hi Lee, I have no favourite brand but most often Western Star unsalted since it’s commonly available here at a good price. The important thing is to ensure it’s unsalted to get the balance of flavours correct.

  5. Hi, I tried this and noticed my cake was sweating a lot, it took just a few minutes of getting it out of the fridge for final coat and it was sweating so that it was extremely hard to smooth the final layer and because I colored my buttercream for the final coat, I could see patches of pink color sweating out while I was adding final touches on the cake

    1. Hi Didi, a bit of sweating is normal so you have to work fast but if it’s excessive then that can mean your working environment is hot or humid. It’s always best to work with climate control (air conditioning) in a closed room if you can if that’s the case. Another way to work around this is to not put it in the fridge as long so it doesn’t cool down as much but still stiffens up a bit. You could also work with a fan blowing on it which will dry it out a bit if the problem is hot air but this won’t work as well for humid air. Hope this helps!

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