Swiss Meringue Buttercream

There are many kinds of buttercream out there, each with their own distinct personalities. German buttercream, my favourite, is made with a pudding or custard base. However, its slightly rustic nature doesn't suit it well for the more haute pastries. For thin, elegant layers, there's rich yolk-based French buttercream. But what if you want a pure-tasting, buttery frosting for a cake that focuses on the butter flavour and little else? You could make an american-style, powdered-sugar buttercream, but those tend to be too grainy for most applications. That's what Swiss meringue buttercream is for. It's incredibly easy, requiring no sugar syrup or difficult steps apart from making sure you don't overheat the egg white-sugar mixture. You don't need to worry too much about pouring the syrup in at just the right moment like with other meringues, so it's a good bet if you're accident-prone. 

Don't panic if you're beating in the butter and it looks really lumpy- as long as you don't add the butter to still-warm meringue, it'll sort itself out if you keep beating. Because it's so simple, you can add any manner of flavouring- I used vanilla and lemon zest, but anything will work. Another nice feature of this buttercream is the pure white colour, making it perfect for colouring and decorating with. You can also freeze buttercream for later very easily, defrosting in the refrigerator overnight and re-whipping if it gets too thick.

Swiss Meringue Buttercream
From Brave Tart

5-6 Oz. Egg whites
5 Oz. Superfine sugar
2  C. (454 g.) Butter
1/4 Tsp. Salt
Desired flavouring: 1 TBSP vanilla extract, zest of 1 lemon, etc.

Mix the whites, salt and sugar with a whisk in a heatproof bowl. Over a saucepan of steaming water, heat until the mixture reaches 150℉ and the sugar dissolves.

Beat at high speed until the bowl's outside has cooled to room temperature. Once completely cool, add the butter in chunks until all is incorporated: it will look curdled for a while, but just keep beating and it will become smooth. Scrape down the sides and mix in. Finally, add your desired flavourings.

Use immediately or freeze for later.