Swiss Meringue Buttercream

Swiss meringue buttercream is a delicious, light and fluffy frosting that’s perfect for cakes because it’s smooth, sturdy enough for piping, and not overly sweet.

How to Make Swiss Meringue Buttercream

Ingredients

Egg Whites

I almost always use fresh egg whites, but you can also use the kind that come in a carton as well.

I found that carton egg whites take longer to whip up and they’re don’t whip up quite as much as fresh eggs do.

It’s also very important that you don’t get any yolk in your egg whites, because any bit of fat will prevent the meringue from whipping.

This also applies to any sort of fat or grease residue that might be left on your equipment, you make sure your bowls and everything are really nice and clean.

Sugar

This recipe calls for regular granulated sugar, but caster sugar or extra fine sugar will work as well. You can even try using brown sugar for a richer taste! Don’t use powdered sugar for this recipe.

Salt

This recipe calls for unsalted butter, so you’ll need to make sure to add salt.

I use kosher salt, which has larger granules. If you only have fine salt, use a little bit less. If you plan to add any flavoring to your buttercream, you might want to adjust the salt to taste.

Butter

You’ll want to make sure your butter is around room temperature, or 68 F. The butter should be soft enough that you can leave an imprint with your finger, but it still holds its shape.

You can use any kind of butter you like, but be aware that the quality of the butter will greatly affect the taste of the final buttercream. This buttercream is about 50% butter, so you’re definitely going to taste it!

Vanilla

Just like with the butter, the quality of the vanilla extract will greatly affect the taste of the final buttercream. With so few ingredients, every single one will have a big impact. Use the best quality vanilla you can, or try using a different flavor extract if you like.

Measurements and Ratios

Using a Scale

I always use a scale to weigh my ingredients because it’s more accurate than using cup measures. So you’ll find this recipe listed in weight measurements.

Using a scale is also great because it saves you from having to wash all those measuring cups!

My Buttercream Ratio

I use a 1:2:3 ratio of egg whites to sugar to butter, and that’s by weight. I use this same ratio when making Italian Meringue Buttercream.

So for example, if I have 100 grams of egg whites, I would use 200 grams of sugar and 300 grams of butter. Using a ratio like this is a great because you can easily scale the recipe to any size you need, or you can adjust the recipe to the amount of one ingredient that you have on hand.

Say I want to use a pound of butter, which is about 450 grams. Knowing that, I’ll then need 150 grams of egg whites and 300 grams of sugar.

You can also adjust this ratio to your personal preference. For example, 1:2:2.5 will give you a lighter, slightly sweeter buttercream, but less butter will also mean less stability. Feel free to experiment!

Making the Swiss Meringue

Cooking the Meringue

Swiss meringue is a meringue that is first cooked over a water bath, or bain marie, before you whip it.

Combine the egg whites, sugar, and a nice heavy pinch of salt into a metal bowl.

On the stove, set up a pot with about a half inch of water in the bottom that is gently simmering.

Place the bowl over the pot and stir gently but continuously. The idea here is to use the steam to gently cook the egg whites. The bottom of the bowl should not actually touch the water, or the egg whites will cook too fast and start to scramble.

Use a rubber spatula to stir this mixture so that you can scrape the bottom and sides of the bowl as the mixtures cooks.

You want to cook this until it reaches 160 F or 71 C. The sugar should all be dissolved and the mixture will be much thinner and more opaque.

If you don’t have a thermometer, you can just cook the mixture until you no longer feel any grains of sugar when you rub it between your fingers. The meringue will still whip up, but you might not reach the proper temperature. For food safety purposes it’s better to use a thermometer.

After the meringue is cooked, I like to strain the mixture into my mixing bowl. This is totally optional, but it’s nice to strain the egg whites to get rid of any chalazae, which are those little strings that keep the egg yolk in place when its inside the shell. There’s nothing wrong with eating them, but they won’t mix in with the meringue and it’s kind of gross to find the little chunks in your finished frosting.

Whipping the Meringue

Have your mixer fitted with the whisk attachment, then whip the egg white mixture on high until stiff peaks form. The meringue should increase in volume and look super white and glossy. When you pull the whisk out of the mixture, small peaks should stick straight up.

Once the meringue is whipped, it needs to cool down to at least 90F/ 32C or below. This is the temperature at which butter melts, so if you add butter before this point, you will have a hot mess.

You can use a thermometer to test, but it’s not crucial. Just feel the bowl with your hand, and if it doesn’t feel warm you should be good to go.

The amount of time it takes to cool down will depend on how big of a batch you’re making, the temperature in your kitchen, and what type of bowl you’re using.

In the video below I’m using a glass bowl so that you can see the process, but a metal mixing bowl will cool down faster.

I typically leave the mixer running on low to continue cooling while I clean up the kitchen. If you want to speed things up a bit, you can hold an ice pack up against the bowl while it mixes, or if you’re working in a very hot room you might need to transfer the meringue to the fridge for 10-15 minutes to cool down.

Finishing the Buttercream

Adding the Butter

If the meringue has cooled down and your butter is soft, it’s time to mix the two!

With the mixer running on low speed, begin adding the butter about a tablespoon at a time. Wait for each chunk of butter to mix in completely before adding the next piece.

The meringue will start to deflate as you add the butter, but don’t worry. Everything will come together as you continue mixing.

If all the butter is added and things still don’t look quite right, don’t panic. Sometimes you just need to keep mixing for a few minutes longer to get everything to come together.

If a few extra minutes of mixing doesn’t help, you probably need to adjust the temperature a bit.

Add the Vanilla

Once the buttercream is smooth, you can mix in your vanilla extract or any other flavorings you like.

It’s also a good idea to scrape down the sides and bottom of the bowl before mixing one last time, to make sure no stray bits of meringue are left unmixed.

Temperature Issues

Ideally, you want the meringue and the butter temperatures to average out to about room temperature in order to mix properly. I find that the buttercream mixes best at about 75F, but anywhere between 70-80F should work.

If your final buttercream is too cold, it will likely look chunky or curdled. It might even split completely, and you’ll liquid meringue oozing around chunks of butter.

To fix split/ cold buttercream, simply remove a small portion to heat up in the microwave. Mix the heated buttercream back in to bring the temperature of the whole batch up. Repeat as necessary until the buttercream comes together.

If your final buttercream is too warm, it will look thin and not have any structure.

To fix warm/ melted buttercream, simply place the whole bowl in the fridge for 5-15 minutes. Scrape down the sides of the bowl and re whip the buttercream. Repeat as necessary until the buttercream comes together.

Working Consistencies

At this point you buttercream is ready to use, although there are a few other things you can do if you’d like to change the consistency a bit.

If you want to make sure the buttercream is perfectly smooth, you’ll want to mix it on low with the paddle attachment for several minutes to knock out any large air bubbles.

You can also gently heat the buttercream to get a looser consistency that is better for frosting a smooth cake. Swiss meringue buttercream that is closer to 70 F will have a stiffer consistency, while buttercream that is closer to 80 F will have a much thinner consistency.

Print Recipe

Swiss Meringue Buttercream

(284 votes, average: 3.51 out of 5)

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Dessert

By Katie – Serves: about 5 cups

A smooth and creamy meringue based buttercream that's perfect for frosting cakes and piping decorations. This recipe makes about 5 cups when whipped properly, which should be enough to frost a 6 inch, 3 layer cake with leftovers for piped decorations.

Ingredients

• 150 grams egg white
• 300 grams sugar
• 1 teaspoon kosher salt
• 450 grams unsalted butter, room temperature (about 68 F)
• 2 teaspoons vanilla extract

Instructions

1

Weigh egg whites, sugar, and salt into a metal bowl. Stir to combine.

2

In a pot with a slightly smaller opening than your bowl, bring about a half inch of water to a simmer. Place the bowl with the egg white mixture over the pot of steaming water, making sure that the bottom of the bowl does not actually touch the water.

3

Stir the mixture gently but continuously with a rubber spatula until it reaches a temperature of 160F/71C. Take care to scrape the sides of the bowl so that all of the sugar gets dissolved into the egg whites.

4

Strain the egg white mixture through a fine mesh sieve into the bowl of your stand mixer.

5

Whip on high speed with the whisk attachment until stiff peaks form and the meringue cools down to below 90F/ 32C. The the bowl should not feel warm to the touch.

6

Once the meringue is ready, whisk on low speed and begin to add the butter about a tablespoon at a time. Wait for each chunk of butter to mix in completely before adding the next piece. After all the butter has been added, you may need to continue mixing for a few more minutes to get everything to smooth out.

7

Add the vanilla extract, scrape down the sides and bottom of the bowl, and mix once last time to combine.

Notes

Ideally, you want the meringue and the butter temperatures to average out to about room temperature in order to mix properly. I find that the buttercream mixes best at about 75F, but anywhere between 70-80F should work.

To fix split/ cold buttercream, simply remove a small portion to heat up in the microwave. Mix the heated buttercream back in to bring the temperature of the whole batch up. Repeat as necessary until the buttercream comes together.

To fix warm/ melted buttercream, simply place the whole bowl in the fridge for 5-15 minutes. Scrape down the sides of the bowl and re whip the buttercream. Repeat as necessary until the buttercream comes together.


STORAGE: Swiss meringue buttercream can be stored at room temperature, lightly covered, for a day. It can also be stored in an airtight container the fridge for 1-2 weeks or in the freezer 3-4 months.