Swiss meringue buttercream (SMB) is a light, silky and buttery alternative to traditional buttercream. It is much less sweet, and therefore allows for the true flavors in the cupcake to shine. It is easy to pipe and holds its shape very well. There are a lot of flavor variations that make this a very versatile frosting. Although it seems like this takes more preparation than other types of frosting, the end results are very rewarding.
The first time I made this frosting, I only used my Martha Stewart cupcake book, which has a couple of good photos but lacked a lot of information for first time SMB makers. After 10 minutes of beating my egg whites and sugar, there was hardly any body to the egg whites. I knew I missed the mark on something but I charged on. The final product tasted fine, but I knew I needed to do more research about SMB.
Before you begin the recipe, here are a few helpful hints I learned from my experiences and from Sweetapolita; one of my favorite bloggers. She has the best tutorial for SMB I’ve seen and some great photos! Check it out here.
- Use only metal utensils. If you must use rubber, make sure they are only for meringue. Remember that the utensils have to be grease-free. I have rubber spatulas which I only use when I have meringue base frosting like royal icing.
- Use lemon juice or vinegar to wipe off all utensils and bowls to remove any lingering oil and grease.
- Use a candy thermometer if you have one, I bought mine at target for $10 and it has been well worth the investment.
- Add the sugar to the bowl, and then add the egg whites right before you are about to start heating the mixture.
- Make sure you use just enough water to cover the bottom of your pot.
- Do not preheat the water to boil it, your eggs will instantly start cooking when you place the bowl on top.
- Do not turn the stove on high; medium heat works best. If you heat the egg whites too fast, they will cook and you have to start over because you don’t want cooked egg whites in your frosting (gross!).
- Make sure you constantly stir or whisk the egg whites and sugar while you are heating them to also prevent them from cooking.
- Make sure your butter is at room temperature before adding it to your frosting. If your butter is too cold, it will not mix well and you will end up with chunks of butter in your frosting.
- To keep your SMB a crisp bright white, use colorless imitation vanilla extract, which can be purchased at a craft store or specialty cake store.
- In the photos shown below, I was making vanilla bean Swiss meringue buttercream. Scroll to the very end to view other variations. The recipe as noted below is for the basic vanilla SMB.
Swiss meringue buttercream (Recipe from Martha Stewart)
Makes about 5 cups, which I find is enough to generously frost 16 cupcakes. Can be used to frost 24 cupcakes depending on the amount of frosting you use for each cupcake.
5 large egg whites
1 C plus 2 tbsp sugar
1 lb (4 sticks) unsalted butter at room temperature
1 ½ tsp pure vanilla extract
- Combine sugar and egg whites in your stainless steel mixer bowl (or any heat proof bowl)
- Attached your candy thermometer to the side of the bowl
- Set your bowl over top of a pot with water, just enough to cover the bottom of the pot. You do not want the water to boil and touch the bottom of your mixing bowl. Heat on medium.
- Stir constantly until the mixture reaches 140° F. This is the most important part; you do not want to egg whites to cook. I have read that you can have it be anywhere between 120° F – 160° F. When it reaches 140° F, the sugar should be dissolved in the egg whites. You can test this by placing a drop on your finger tips and rubbing them together. The mixture should be completely smooth.
- Place the mixing bowl on your stand. Using the wire whisk, beat the eggs. Start on low and increase the speed to medium after 2 minutes.
- Beat for another 3 minutes on medium. At this point, your frosting should have turned white as the egg whites are whipped and the body of the meringue starts to form.
- After 5 minutes, increase speed to high. You will notice that as you increase the speed, the body of your meringue will also increase. It will start to look glossy as the peaks begin to form. Beat for another 5 minutes.
- After you have beat the meringue for a total of about 10 minutes, the bottom of your mixing bowl should be cooled completely. Your SMB should look kind of like whipped cream. Scrape down all sides and bottom of the bowl.
- Turn your mixer down to medium-low. Slowly add your butter, about 1 tbsp at a time, ensuring it is mixed well after each addition. Once you have added all your butter, slowly add vanilla extract. Mix for another minute and scrape down the sides of the bowl.
- Switch to the paddle attachment and continue beating on medium to allow all the air bubbles to escape. In about 2-3 minutes the frosting is smooth.
To tint the buttercream, slowly add the color gel and beat with paddle attachment or fold in with a spatula until completely incorporated. I prefer to use Ameri color or Wilton gels, either which can be purchased at a craft store or a specialty cake supply store.
You can keep the SMB at room temperature if you are planning to use the same day. Otherwise, you can keep it in an airtight container in the fridge for up to 3 days (according to Martha’s recipe). Before you are ready to use, take it out of the fridge and allow it to come to room temperature. Place back in your mixer (don’t forget to wipe down with Vinegar) and beat on medium speed with the paddle attachment for 3-5 minutes.
Vanilla bean: Before combining your sugar and eggs whites, place sugar in a food processor. Split 1 vanilla bean and scrape the seeds out, placing into your sugar.
Use a food processor to combine the vanilla beans and sugar and pulse until well combined.
Mix until well incorporated. Before transferring the sugar into your mixing bowl, use a fine sieve to filter out any pieces of the vanilla bean skin that shouldn’t be there. Begin with step 1 to cook the vanilla sugar with the egg whites. I still added the vanilla extract in step 7.
Cinnamon Swiss meringue– I love to use this on my apple pie or pumpkin cupcakes, just add cinnamon 1 tsp at a time after adding the vanilla until desired taste is reached. I usually use 2 tsp.
Other variation from Martha Stewart that I have not tried yet:
Chocolate- Melt 4.5 ounces semi-sweet chocolate, cool to room temperature. Fold into buttercream using your spatula after adding vanilla extract.
Coffee- Mix 2 tbsp of instant espresso powder (not instant coffee) at the same time as vanilla extract
Raspberry- Beat about 6 oz of fresh raspberries (or other berries) into frosting after all butter has been added, until the buttercream is streaky. Be careful not to over beat.
Martha Stewart’s cupcake book has a different recipe for Strawberry meringue buttercream as well, which I hope to make sometime soon. I highly suggest purchasing this book!
Editors note: Cupcake stands purchased from The Pampered Nest