Kitchen magic

There's been a trend recently in some of the things I've been cooking, and that is the seeming certainty of failure followed by the sudden realization that what you're cooking is just fine after all. Lemon curd, ginger lime curd, even a new tart pastry I tried: they look absolutely awful, and you're sure you've failed miserably, but then in the blink of an eye it all comes together. It's like magic, and it's great fun.

The newest addition to my "things fall apart, but then they come back together" repertoire is buttercream icing. I had the impression that it was difficult, that it was easy to undercook the egg whites and kill your guests, that it was temperamental, and so on. Now, having made it, I don't think any of that is true. In fact, it's easy.

Dead simple, too: all you need are egg whites, sugar, butter, and maybe a dash of cream of tartar. Your egg whites are cooked in a double boiler, and what with all the sugar you've whisked into them, they won't coagulate even if you whisk them only rarely as they cook. Brilliant! Deb at Smitten Kitchen instructs you to keep the egg whites and sugar over the simmering water until you can no longer feel the sugar granules between your fingers, but that felt a little too hand-wavy to me--particularly as this was my first time making the stuff. I went with Joe Pastry's thermometer method: when the whites reach 160F/71C, they're sufficiently cooked (adios, salmonella) and it's time to whip.

And oh, is it ever time to whip. I highly recommend using an electric mixer (of the hand or stand variety) rather than whisking by hand. Otherwise there's a good chance that you'll give yourself a repetitive stress injury. You whip your (cooked, but still liquidy) egg whites, and whip them some more, until they hold stiff peaks. And then you do something that you'll regret for a few minutes: you add butter.

Resist the urge to shed a few tears when you start adding the butter. You will think you've ruined your gorgeous, stiff meringue and turned it into a curdly soup of egg and butter. But you haven't. If you've ever made brioche, you know what I mean. Keep the mixer going, and all will be well. Add the butter a bit at a time, being glad that you've taken the time to allow it to come to room temperature, and keep beating. Even after you've finished adding the butter and it looks like it's all incorporated, keep beating. Eventually--and this might take a few minutes or several--you'll glance worriedly at the clock, wondering if it's been too long and you really have ruined it, and when you look back at the bowl your gloppy mess of butter and egg whites will have turned into something that looks a bit like heavily whipped, almost over-whipped cream. But it's better than whipped cream, it's buttercream, and it's heavenly.

Short and sweet version of the recipe, with amounts, below the fold.

Swiss Buttercream

Makes enough to cover a 2-layer 9" cake

Ingredients

• 4 egg whites
• 1 cup sugar
• 1/4 teaspoon cream of tartar
• 1 pound (2 cups) unsalted butter, room temperature

Directions

1. Whisk together the egg whites, sugar, and cream of tartar in a heat-proof bowl set over simmering water. The water should not touch the bottom of the bowl. Whisk intermittently as the mixture warms.
2. When the mixture reaches 160F/71C, remove the bowl from the heat. Transfer the mixer to a different bowl (such as that of a stand mixer), if using, or just whip them in the bowl they're in now. Beat at medium to high speed until they hold stiff peaks.
3. Add softened butter, one or two tablespoons at a time, and beat at medium speed until all butter is incorporated.
4. Increase speed to high and beat until it's done. You'll know when it's done, because its consistency will change rather obviously.
5. Beat in any flavorings, if desired (vanilla extract, almond extract, etc.), and use immediately or store until needed. Buttercream keeps, refrigerated, for up to one week. It can also be frozen. Either way, bring to room temperature and beat again before using.