Raspberry Swiss Meringue Buttercream
Tart, buttery smooth swiss meringue raspberry buttercream - naturally pink.
The beauty of a swiss meringue buttercream is that, unlike American style frostings (a basic mix of powdered sugar and butter) it isn’t overly sweet. This is because rather than adding a ton of sugar to provide stability, most of the body comes from whipped egg whites (which are cooked & safe to eat). Sometimes a swiss meringue buttercream can be a bit overly ‘buttery’ in flavor but the beauty of this recipe is that the raspberry masks it beautifully: it’s gives it a bright berry, slightly tart and definitely raspberry flavor.
Recipe Origins
This recipe was created for my raspberry lemon cake (lemon cake layers, lemon curd, fresh raspberries and this buttercream!). I started working on it from serious eats’ vanilla swiss meringue recipe. I make less of the recipe, use regular sugar and a bit less of it, and of course add freeze dried berries.
Recipe Ingredients
Egg whites: There can be absolutely no egg yolk/yellow in the egg whites or they won’t stiffen. Any kind of fat gets in the way of a meringue (so be sure to make sure your bowl, hands and utensils are clean too!).
Sugar: fine granulated sugar.
Cream of tartar: this is to help stabilize the meringue. If I don’t have this I’d use a half a teaspoon of fresh lemon juice.
Butter: unsalted or salted but if you are using salted then skip the added salt to the buttercream. The butter should be at a soft room temperature so it incorporates easily into the meringue.
Freeze dried raspberries: these are dehydrated raspberries, I get them from Target (where they are cheapest) and I use them because they’ll add raspberry flavor without changing the texture of the buttercream. Fresh or frozen raspberries will add too much water – unless you puree then cook down the water (but this can also alter the flavor so I don’t love it).
How to make Raspberry Swiss Meringue Buttercream
Whisk then cook the egg whites & sugar: we’ll do this in a double boiler, with the sugar & egg mix in a bowl set over simmering water.
With the bowl over the simmering water, stir it the meringue and keep cooking and stirring, scraping up the sides of the bowl as you do, until the sugar has dissolved, this can take up to 10 minutes depending on the heat level.
If you have a thermometer, the temperature should reach about 180 F. Checking by hand, lift the spatula with some of the meringue and as it falls, pinch a bit between your finger and thumb – once you cannot detect sugar granules, it’s ready to be whipped.
Whisk to stiff peaks: Transfer the mix to the bowl of a stand mixer and affix the whisk attachment. Add the cream of tartar (this helps stabilize the meringue) and turn the mixer on low and work it up to medium speed.
After about 6-9 minutes, the meringue should hold stiff peaks (the time can vary based on the strength of the mixer, if you’re using a hand mixer it will take even longer). You’ll know it’s at stiff peaks if you can turn the whisk upside down and the meringue at the top doesn’t droop.
Grind the raspberries and sift in the powder: Wait to do this until right before adding the powder to the meringue because if you do it early, the powder can clump as it absorbs moisture from the air. Grind the berries in a food processor or blender then sift the powder into the meringue using a fine mesh sieve. Discard the bigger bits and seeds or save them to use them to decorate the cake.
Slowly add the butter: Turn the mixer on and slice the butter into pats that are about one tablespoon each, add them slowly to the mixer – one at a time. Take your time doing this.
Once all the butter is in, buttercream will look broken. Keep that mixer on and whisk until the buttercream starts to come together and look glossy, it can take awhile (5-10 minutes). You can test it’s doneness by swiping your finger into the buttercream and if it’s smooth, it’s ready to pipe and spread.
Troubleshooting raspberry swiss meringue buttercream
The sugar won’t dissolve
The heat probably is too low and the water isn’t simmering. Raise the heat to a strong simmer and keep warming it until it dissolves.
The meringue won’t reach stiff peaks
First tip: don’t use a hand mixer, they can’t whip air into the meringue as fast and as strongly as needed. If you’ve used a stand mixer and you still can’t get to stiff peaks after 15+ minutes there’s a chance the bowl was oily or a bit of egg yolk was left in the whites. Fat will stop a meringue from stiffening and unfortunately, there’s no fix for it and you’ll have to start over. Another culprit can be humidity.
The buttercream looks curdled and not smooth
This will happen as you add the butter, and it might even look like a broken soupy mess once all the butter is in. Just keep whipping it until it comes together. Check on it – sometimes it’ll look bubbly but if you stop it and use the back of a spoon to smear it you’ll see it’s actually done and ready for frosting.
Storing the buttercream
Swiss meringue buttercream will keep for 24-48 hours at room temperature. If you need to store it for longer, scoop it into an airtight container and set in the fridge for up to a week. Before using it to frost the cake, bring it to room temperature then whip it until smooth.
Raspberry Swiss Meringue Buttercream Recipe
Raspberry Swiss Meringue Buttercream
Ingredients
- 4 egg whites from four large eggs
- 224g or 1 cup plus 2 tablespoons fine granulated sugar
- ½ tsp fine sea salt
- ¼ tsp cream of tartar
- 2 tsp pure vanilla extract
- 35g freeze dried raspberries
- 339g or 3 sticks unsalted butter softened
Method
- Have the butter at room temperature.
- Find a heatproof bowl (glass or metal) that will fit over a medium sized pot. Fill one third of the pot with water and set over medium low heat.
- Once the water is at a simmer, set the egg whites in the bowl you’ve selected and as you pour the sugar in, whisk to combine. Once this is well mixed, set over the simmering water.
- Keep a small rubber spatula handy and stir the mix frequently, scraping up the sides of the bowl to ensure all the sugar melts.
- Check the sugar often by stirring then raising the spatula so that some of the mix falls, as it does pinch a bit between your fingers; if you can detect any sugar granules it needs more time. If you cannot, it’s done.
- Transfer the egg mix to the bottom of a clean bowl of a stand mixer and affix the whisk attachment. Start whisking on low then work up to medium. Add the cream of tartar.
- Whisk the meringue until it can hold stiff peaks: you should be able to turn the whisk upside down and the meringue won’t droop. As it’s whisking, add the vanilla and salt.
- Once you have stiff peaks, grind the freeze dried berries in a food processor then sift it over the meringue. Discarded the seeds and bigger bits.
- Turn the mixer on low, and, one tablespoon at a time, add the butter - no need to wait until each pat is incorporated, just work slowly. Once all the butter is in, the buttercream will look broken, don’t worry! Keep whisking until the buttercream is thick and you can swipe your finger into it and it’s got a smooth texture.
Did you make this recipe?
Share & tag me on instagram @buttermilkbysam
This is delightful. I love all SMB, generally, but the raspberry powder comes through so nicely but the texture is still smooth. Paired with your black cocoa cake recipe for a birthday dessert.
This recipe worked very well, and I was able to get a stable buttercream with slightly less butter than the recipe called for. I added it a tablespoon at a time and stopped when I felt comfortable with the consistency. The flavor was a perfect balance of sweet and tart and was packed with raspberry flavor, and I love the natural pink color.
I’m just wondering why Juliet added flour 🤣
Juliet, flour?
I would try this recipe if it called for fresh or frozen raspberries. I grow a lot of them in my yard. I don’t know how to freeze dry them but will look into it.
Just made this and I am so disappointed. It is virtually inedible. Far too much flour I think. I weighed it rather than doing it by cups so it should have been fine. Will have to redo, with a different recipe, such a shame.
I think the butter ratio is off on this recipe. I made it and it basically tastes like raspberry butter. I had to add 2 cups of powdered sugar to make it work for my cupcakes.
Tbh most swiss meringue buttercreams taste like butter =( I try to avoid this as well and will sometimes add up to 1/4 cup less but it depends on the buttercream and how much structure it needs from the butter.