Swiss Meringue Buttercream (referred to as SMBC) is made from cooked egg whites, sugar, and flavorings to create the ultimate silky smooth frosting. It is light, not too sweet, and a dream to work with. It will be the star of any cake you make.
Why use Swiss Meringue Buttercream
This is my favorite buttercream to use. Though it is seems daunting at first, it is worth the time and effort to learn if you like to make layer cakes. SMBC is stable at room temperature, but I would recommend keeping it in the fridge on particularly hot or humid days.
Three steps to the perfect buttercream
Swiss meringue buttercream is made using three steps. First, in a double boiler system cook the egg whites and sugar until it reaches 161 degrees on an instant read thermometer and it is not grainy. Stir frequently as it cooks. I use the mixer bowl as the top of the double boiler. Once the egg sugar mixture has come to temperature, whisk it using a stand mixer until stiff peaks form. Stiff peaks will hold their shape, even when flipped upside down. Last, slowly add in the butter with mixer running on high using the whisk attachment.
Frequently Asked Questions
A typical American buttercream is make with butter and confectioners sugar and there are no eggs in it. An Italian Meringue Buttercream is made by pouring hot sugar syrup into whipped egg whites and then adding butter. It is the most stable, but tricky to pour hot sugar into the egg whites. Where the SMBC has you cook the egg whites and sugar together first and then whip them. No need to pour boiling hot sugar syrup until a moving mixer.
No- this buttercream will not develop a crust or dry out. It is super easy to work with and will keep its shape and texture.
Yes- the eggs are cooked.
Yes- you can add in flavors or colors. I would recommend using gel food coloring so you are not adding more liquid. For flavors, you can add 1/2 to 1 1/2 teaspoons of flavoring at the end. Start with the smaller amount and work your way up.
SMBC can be made ahead of time. I often make it earlier in the day and leave in on the counter until I am ready to frost. It can also be kept at room temperature for 1-2 days, refrigerated about a week, and frozen up to 3 months. If you store it in the fridge or freezer, you will need to let it come to room temperature and rewhip it.
To make SMBC, you will need a stand mixer (it whips for a long time), a double boiler system, and a instant read thermometer.
You can try- but humidity and merginues do not pair well together. Really hot and humid weather can prevent the egg whites from reaching stiff peaks. In addition, if it is really hot or humid, the butter will melt and it is best to store the finished cake or SMBC in the fridge.
It depends on how big of a cake and how much you are decorating. A single batch will fill and cover a 8 inch 3 layer cake, heavily frost 12 cupcakes, or lightly frost 24 cupcakes. I tend to like to have more than less frosting when I making a cake. Your mixer will most likely only be able to handle a single batch. My Kitchen Aide PRO can do a 1 1/2 batch.
Tips and Troubleshooting
PRO TIP 1: Make sure your mixer bowl and paddle are clean with no residual grease or crumbs in them to prevent the merginue form whipping.
PRO TIP 2: To avoid ruining all your egg whites, separate your eggs one at time into two small bowls and pour each egg white into mixer bowl one at a time. There is nothing worse then a cracked yolk on your last egg.
PRO TIP 3: The butter needs to be soft. You should be able to easily push a finger into it. I also like to cut my butter to small 1/2 sized cubes to make it easier to incorporate in the meringue.
Troubleshooting 1: I add the butter and it looks curdled or I still see small bits of butter. This happens. You have two choices. First, just keep mixing. Usually comes together with some extra time. If that does not work, place your mixer bowl over the simmering pot until the sides start to melt, but the middle is still in tact. Then return to the mixer and beat again on medium until it comes together about 30-60 seconds. This is a very common problem and I often need to do this.
Troubleshooting 2: My mixer is overheating. It is fine to pause and give your mixer a break. Place the bowl and whisk attachment in the fridge for 20-30 minutes until the mixer cools down.
Recipes that use Swiss Meringue Buttercream
Lemon Cake
Swiss Meringue Buttercream
Equipment
- Stand Mixer with whisk attachment
- Double Boiler Set Up
- Instant Read Thermometer
Ingredients
- 6 egg whites room temperature
- 2 cups butter room temperature
- 1 1/2 cups sugar
- 1/8 teaspoon salt
- 1 teaspoon flavoring (Vanilla)
Instructions
- Place a large pot with a couple inches of water on the stove and bring to a simmer. Make sure the mixer bowl can tightly fit in the pot and not touch the bottom.
- In mixer bowl combine the egg whites, sugar, and salt. Whisk to combine.
- Place mixer bowl over boiling water and cook until it reaches a temperature of 161 degrees or is not grainy. Whisking consistently. This should take about 4-5 minutes. If you don't have a instant thermometer, carefully place your finger or a spoon in the mixture and rub it together. If you can feel any sugar grains it is not ready.
- Remove from heat and whisk in a stand mixer on high until the bowl is no longer hot and stiff peaks have formed. About 10-15 minutes. If it very hot or humid out, this can take longer. Give your mixer a break if needed and place the bowl and whisk in the fridge for ten minutes.
- Slowly add butter to the stiff peaks with the mixer running on high. Wait until the butter has been absorbed to add in more. Whisk on high until all the butter has been added and incorporated. Sometimes, I continue mix it on high after all the butter has been added to make sure everything is smooth. The buttercream should be silky and smooth at this point. See Tips and Troubleshooting if the butter is not mixed in all the way or it looks curdled.
- Add in salt, flavorings and color at this point. Then frost away!
Notes
- You can half this recipe. I can make a batch and half in my kitchen aide PRO, but it is better to make two batches than overheat the mixer.
- This makes enough to cover and fill a 3 layer 8 inch cake, heavily frost 12 cupcakes.
- Temperature is a big factor in SMBC. If the butter is too cold it will not mix in. If the egg whites are too warm the butter will curdle. But everything it fixable by either cooling or warming up the necessary ingredients.
