- 10 large fresh egg whites (300 g)
- 2-1/2 cups 500 g sugar
- 3 cups 680 g unsalted butter, cut into cubes and cool, but not cold
- 1 tablespoon + 1 teaspoon 20 ml pure vanilla extract
- pinch of salt
- Wipe the bowl of an electric mixer with paper towel and lemon juice, to remove any trace of grease. Add egg whites and sugar, and simmer over a pot of water (not boiling), whisking constantly but gently, until temperature reaches 140°F, or if you don’t have a candy thermometer, until the sugar has completely dissolved and the egg whites are hot.
- With whisk attachment of mixer, begin to whip until the meringue is thick, glossy, and the bottom of the bowl feels neutral to the touch (this can take up to 10 minutes or so). *Don’t begin adding butter until the bottom of the bowl feels neutral, and not warm.
- Switch over to paddle attachment and, with mixer on low speed, add butter cubes, one at a time, until incorporated, and mix until it has reached a silky smooth texture (if curdles, keep mixing and it will come back to smooth). *If mixture is too runny, refrigerate for about 15 minutes and continue mixing with paddle attachment until it comes together. Add vanilla and salt, continuing to beat on low speed until well combined.
- Add additional flavours, purees, as desired.
*Keep in airtight container in refrigerator for up to one week, leaving out at room temperature when needed, rewhipping in mixer for 5 minutes.
**Can freeze for up to 6-8 weeks. To thaw, place on counter overnight, and rewhip for 5 minutes with paddle attachment in an electric mixer.
***If buttercream still doesn’t have its satiny finish after rewhipping, microwave 1/3 of the buttercream for approximately 10 seconds and add to remaining buttercream in mixer bowl, beating for a few moments to incorporate.
Sweetapolita’s Notes on a few Variations:
- Chocolate Buttercream: Add 300 g (1 1/2 cups before melting) melted bittersweet high quality chocolate (the best you can get–I use Callebaut) for every 5 cups of vanilla Swiss Meringue Buttercream and beat until incorporated.
- Strawberry Buttercream (or any other berry version): Add fruit puree to taste (approximately 1/2 cup for 5 cups of SMB).
- Vanilla Bean Buttercream: Add 1 tablespoon of vanilla bean paste OR 1 vanilla bean, scraped for every 5 cups of SMB, and beat until incorporated.
- Lemon Buttercream: Eliminate vanilla extract and add 1 teaspoon of pure lemon extract for every 5 cups of SMB, or to taste, and beat until incorporated.
- You can also add liqueurs and other flavourings, as well as any food gel colours to achieve any desired colour.