Creamy and velvety smooth, this ultra rich white chocolate Swiss meringue buttercream pairs perfectly with cakes and cupcakes. It’s incredibly versatile and tastes amazing!
When it comes to cakes and cupcakes, there are so many types of frostings to choose from, like Swiss meringue buttercream or milk chocolate Nutella frosting. It’s honestly impossible for me to choose a favorite because they are all so creamy and delicious. In fact, I could eat straight frosting with a spoon instead of spreading it on a cake the way it’s supposed to be eaten. That’s how much I can’t get enough of the stuff!
This white chocolate Swiss meringue buttercream is rich, ultra creamy and tastes amazing layered on a cake or piped onto cupcakes. The white chocolate flavor is not overwhelming and balances perfectly with the velvety smooth texture.
What is Swiss meringue buttercream?
Swiss meringue buttercream is one of several classic types of buttercream. It involves making a meringue with cooked egg whites and sugar, and then gradually adding butter as you whip the egg whites, transforming it all into a magnificent frosting. It’s incredibly versatile, too, because you can flavor it any way you like. I always add vanilla extract to the base, but you can add in other extracts or flavors, and even melted chocolate, which is what this recipe calls for.
Swiss meringue buttercream does involve a bit of technique. But don’t worry, I’m going to walk you through every step so you can make it perfect! Keep in mind that making this recipe is all about temperature control. Pay close attention to any temperatures the recipe calls for.
How to make white chocolate Swiss meringue buttercream
- Cook the egg whites and sugar. The first step is to combine the egg whites and sugar in a stainless steel or glass bowl that fits over a saucepan. Fill the saucepan a third of the way with water and place the bowl on top on the stovetop creating a double boiler. Keep the flame on medium to low, allowing the heat to gently cook the eggs and melt the sugar. While you don’t need to constantly whisk the eggs, whisk them every minute or so to prevent them from scrambling. Once the sugar is completely melted and the egg whites feel smooth and warm between your fingertips, you’ll know it’s ready to be whipped.
- Make a meringue. Pour the cooked egg white mixture into an electric mixer fitted with the whisk attachment. Add the salt and turn the mixer on high and whip until the egg whites form a meringue. It will appear silky and shiny, but continue whipping until the meringue has cooled down to room temperature. This can take awhile, around 10 minutes or so.
- Add the butter. Once the meringue has cooled to room temperature, slowly add room temperature butter to mixture a few pieces at a time while the meringue continues to whip. Do not turn off your mixer. Allow the butter to gradually emulsify and form beautiful, luscious buttercream! This can take a few minutes as well, so allow it to whip for 3-5 minutes. Don’t be surprised if it appears curdled – this is just the process of the buttercream emulsifying.
- Add melted white chocolate. Once the buttercream is made, add the vanilla and slowly pour in cooled, melted white chocolate and whip together until combined. Make sure the white chocolate isn’t too warm or it will melt the buttercream.
Any issue you have making Swiss meringue buttercream, I can guarantee has also happened to me! I’ve made this more times than I can count and have learned a lot about how to fix any issues. Here are some common problems you may encounter and how to solve them:
Issue: My egg whites didn’t whip into meringue.
Here’s how to fix it: This is most likely because there was fat from either egg yolk or butter that made it’s way into your egg whites. Fat inhibits egg whites from whipping, so the best course of action here is to start over and be extra careful not to get any yolk in your eggs if separating them yourself.
Issue: My buttercream appears clumpy or curdled.
Here’s how to fix it: The buttercream will likely appear this way when you first add the butter, but allow it to whip for 3-5 minutes to completely emulsify. If it doesn’t and the buttercream remains curdled looking, the butter was too cold when you added it (the clumps you see are actually tiny clumps of cold butter). To fix this, scoop a bit of buttercream into a microwave-safe bowl and microwave until slightly melted. Add it back to your mixer with the curdled buttercream and whip together for 1-2 minutes. If the buttercream is still appearing curdled, repeat this step again until it appears smooth.
Issue: My buttercream looks soupy.
Here’s how to fix it: This happens when the butter melts after it’s added to the meringue, usually because the meringue was still warm. To fix it, scoop about a cup of the melted buttercream into a bowl and place it in the freezer for 10 minutes. Then, add it back to the mixing bowl and whip together and watch the ingredients transform into a beautiful buttercream as the temperature equalizes.
Issue: My buttercream is gritty.
Here’s how to fix it: This is most likely because the sugar didn’t completely melt when you cooked it with the egg whites. To prevent this, I like to use both a whisk and spatula to stir the egg whites and sugar over the double boiler, being sure to really pull all sugar out of the bottom sides of the bowl to make sure it all melts. If you discover this after the butter is added, you have two options. You can start over, or follow this pretty unconventional way to fix it if you’re up for a bit of a challenge (but it will work!):
- Put all of your buttercream back over a double boiler and melt it.
- Stir occasionally until it gets hot enough to melt the remaining sugar.
- Put the melted buttercream in the refrigerator for about 10-15 minutes. It will be slightly tacky. Place in the mixer and whip for several minutes.
- At this point, it’s a game of equalizing the temperature, so, as mentioned above, if it appears soupy still, you may have to chill a portion of it. Add it to the remaining buttercream, whip it, and see what it looks like it. If it looks curdled, melt some and add it back to the mixer.
- Continue to whip until smooth and fluffy buttercream forms.
Tips for making perfect white chocolate Swiss Meringue Buttercream
- Cook the egg whites on a low flame. Even though you are using a double boiler, you need to be careful not overheat the egg whites. This can cause them to scramble or burn. I recommend keeping the flame somewhere between low and medium heat.
- Keep your egg whites away from fat. Fat inhibits egg whites from whipping into meringue, so if any yolk or butter gets into your egg white-sugar mixture, it won’t whip up properly.
- Use room temperature butter. This ensures it emulsifies properly into the meringue.
- Wait until the meringue is cooled to add the butter. If your meringue is still warm when you add the butter to it, the butter will melt and your buttercream will appear soupy. See Troubleshooting section above on how to fix this).
- Don’t stop whipping! It can take several minutes for butter to completely emulsify into the meringue. Allow it to whip for at least 5 minutes before exploring any troubleshooting options.
- Make sure the melted white chocolate is cooled. If you add the chocolate while it is still too warm, it will melt your buttercream.
Cakes that pair amazing with white chocolate Swiss meringue buttercream
Swap out the frostings in any of these recipes for this luscious, white chocolate Swiss Meringue buttercream instead!
- My Favorite Chocolate Birthday Cake
- Gender Reveal Cake
- White Cake
- Red Velvet Cake
- White Chocolate Cake
Creamy and velvety smooth, this white chocolate buttercream is ultra rich and pairs perfectly with cakes and cupcakes.
- 5 large egg whites
- 1 1/4 cups (250g) granulated sugar
- 1/4 teaspoon salt
- 2 1/4 cups (500g) unsalted butter, softened to room temperature
- 1 1/2 teaspoons pure vanilla extract
- 130g (4.5 oz.) white chocolate, melted and cooled
In a heatproof bowl, combine egg whites, sugar, and salt, and set mixture over a saucepan of simmering water, keeping heat on low. Constantly yet gently whisk mixture by hand until warm to the touch and smooth, and sugar has completely dissolved. If you have a thermometer, the temperature should reach 150F/65C. Remove from heat.
Using an electric mixer fitted with the whisk attachment, whisk egg white mixture until stiff peaks form and meringue is thick and glossy, about 10 minutes (start with low speed and gradually increase to medium-high). Make sure the bottom of the bowl isn’t warm before adding the butter, otherwise it will melt.
On low speed, add a few tablespoons of butter at a time, beating well after each addition until incorporated. Once all butter has been added, keep beating until very smooth. If at some point the mixture curdles, keep beating until smooth again. Add vanilla and beat on low speed until combined. Finally, add the melted, cooled white chocolate and combine.
Frosting can be kept in an airtight container in the fridge for up to a week, or in the freezer for up to 2 months. Before using, bring to room temperature and whisk by hand for a few seconds until satiny and smooth.