Have you ever wondered why Swiss Meringue Buttercream (SMBC) recipes have you scrupulously clean your mixing utensils and create a perfect fluffy meringue when you are just going to douse it with butter and kill it? Have you ever made SMBC and added all of the butter only to have it remain soupy or curdled looking? I have! At that point I begin to worry and start chilling bowls and adding more butter so it will come together. But no more! After extensive research and experimentation I have come up with a recipe that comes together every time. And you may be quite surprised by how it is made.
Most meringue buttercream recipes begin with, well, meringue. But what confused me was why a meringue was made when it was just to be deflated with bubble popping butter? At first I thought that the denaturation of egg proteins might be essential for the emulsification process. Most of the hydrophobic (fat loving) amino acids exist tucked inside the inner folds of a protein. When eggs proteins are beaten they essentially unwind exposing the inner amino acids which could then interact with butter as an emulsifier.
This theory was easy enough to test. I just didn’t beat the eggs and sugar to a meringue. I expected it would never reach a thick, beautiful, emulsified buttercream, but I was wrong. It made a lovely buttercream without the meringue and it made it more consistently. What I discovered is that the butter(amazing wonderful butter!) is doing the emulsification work. So my recipe starts with butter and then adds the egg-sugar syrup to achieve a reliably emulsified buttercream.
Here is the process step-by-step.
1. Combine egg whites and sugar in a heatproof bowl or top of a double boiler. I use pasteurized egg whites because it is easier than cracking eggs and they are free of bacteria.
2. Place over simmering water to dissolve sugar. You have such a high concentration of sugar that heat is needed to get it all dissolved. Stir until a spoon scraped along the bottom glides smoothly without the feeling of grit.
3. If using unpasteurized eggs heat the mixture to 160 F to ensure that the mixture is free of salmonella.
4. Once the sugar is dissolved and the desired temperature reached, cool the mixture to a cool room temperature. I place my mixture in a cake pan to maximize surface area and pop it in the freezer for 15-20 minutes.
5. Meanwhile soften your butter to a cool room temperature and beat it in your mixer bowl for about a minute until creamy and slightly lightened in color. (For lighter colored fluffier buttercream beat on high for 2 minutes).
6. When the syrup is cooled gradually add it to the butter with the mixer on med-low speed. When it is all added, scrape down the sides of the bowl and beat on med-high for 2 minutes. The buttercream will be firm at this point.
7. Reduce mixer speed to low and mix in the vanilla extract. Once added return the speed to med-high and beat for 1 minute. This will lighten the texture of the buttercream and make it creamier.
That is it! Use this lovely buttercream to frost your favorite cake or cupcakes.
A few quick notes on SMBC:
- You can make up a quantity of the egg-sugar syrup and store it in the freezer to aliquot as needed. It will not freeze solid and is easy to measure out. Return to room temperature before adding to butter (can be warmed carefully in the microwave for a few seconds at a time).
- Less butter gives a more firm buttercream at room temperature but softer when chilled and vice versa.
- This recipe is formulated at 1:2:2 for eggs:sugar:butter by weight. More sugar gives a sweeter but less creamy final product. Less sugar results in a creamier and more buttery tasting buttercream.
Use this information to formulate your ideal buttercream proportions.
The cake in the photos is a white cake that I am working on for you all. It is not quite right just yet, but when it is perfect I will post the recipe for you!
Happy baking 🙂
- 8 ounces (227 grams) egg whites from whole eggs or a carton
- 16 ounces (454 grams) granulated sugar
- 16 ounces (454 grams) unsalted butter softened but not warm
- 2 tablespoons vanilla extract
- Combine the egg whites and sugar in a heatproof bowl or the top of a double boiler and set over simmering water, stirring periodically, until the sugar is dissolved and the temperature reaches 160 F (71 C) if using cracked eggs.
- Remove from heat and cool to a cool room temperature, 60-65 F (16-18 C). This can be done in the freezer, refrigerator, an ice bath, or at room temperature.
- Meanwhile, beat the butter in a mixer bowl with the flat paddle attachment on medium-high for about 1 minute until creamy and slightly lightened.
- Reduce speed to medium-low and gradually add the cooled sugar syrup to the butter. Scrape down the sides of the mixer bowl and beat on medium-high for 2 minutes.
- Reduce speed to low and slowly add vanilla extract. Increase speed to medium-high and beat for 1 minute until light and creamy.