Adventures in Baking 101: Icing Cakes

Baking class, week seven. This week we’ll be making icings for the two cakes we made last week: a Swiss meringue buttercream, and a chocolate ganache.

The Swiss buttercream begins with a mixture of egg whites and sugar, whisked over a double boiler until it reaches 130 degrees F. At that point it’s transferred to the mixer, where it’s whisked for fifteen minutes until light and fluffy. (“Light and fluffy” comes up a lot in cake making.) An enormous amount of cubed softened butter is then added, slowly and rhythmically, while the icing is being flagellated with the paddle attachment for another fifteen minutes.

Cubed butter for the Swiss meringue buttercream.

The final concoction is so bright and thick it doesn't seem possible that it was made from natural ingredients. The whipped egg whites and sugar give the icing an almost unnatural sheen. There is just the slightest tinge of pale yellow from the butter. The texture is thick and viscous, like an industrial plastic. It is very, very delicious when applied to cakes.

The Swiss meringue icing before the addition of butter.

The chocolate ganache is simpler to prepare but equally delicious. Heavy cream is brought to a boil and poured over chunks of semisweet chocolate. The chocolate melts and, after some whisking, the mixture is removed to the refrigerator until it reaches spreading consistency.

Chocolate ganache. The next day I rolled this into balls and made some incredible truffles.

Preparing the icings takes a while but the tricky part is yet to come. The white butter cake from last week needs to be trimmed and cut horizontally into three layers. Icing will be applied between the layers and on the top and sides. To make a nice looking cake, the three round sections should be flat and as equal in size as possible. That’s not easy to pull off, especially when your cake is neither perfectly round nor perfectly flat to begin with.

At times like this I begin to understand the attention to detail required to be a good baker. I see that imperfections at one stage lead to challenges later on. Not that mistakes can’t be overcome, because part of being a good baker is learning to mask imperfections so they become indiscernible. It’s just that things tend to go more smoothly if care is taken at every step in the process.

The butter cake, iced with Swiss meringue buttercream, before decoration.
The genoise cake is in the background.

The class is divided into groups of two students per cake, but my partner has had to leave early so I do the cake trimming and icing on my own. I don’t imagine myself as being particularly good at this kind of thing, but somehow I pull it off with acceptable results and get kudos from Chef Sandy. The cake is not perfectly round but at least it’s flat. The icing has a smooth texture with no hint of graininess (from undissolved sugar crystals), and tastes buttery and rich. Not bad for my first time.

Impromptu "cornets," made from parchment paper. In a pinch these can be
filled with icing and used for cake decoration. They fall apart easily.

Ten minutes before the class ends, things are running late. Most people are packing up but I decide to stay and put a few rudimentary swirls and decorations on my cake. It’s amazing how even the simplest decorations improve the delectability of a cake.

The final decorated butter cake.

I don’t have time to ice the second cake (the genoise), so take it home with the ganache, which by this time has solidified to the point of not being spreadable. The next day at home I roll the ganache into one-inch balls, then dip each into either cocoa powder or chopped hazelnuts to make impromptu chocolate truffles. They are SO good.

Take home: one white butter cake with lemon buttercream icing, one plain genoise cake, chocolate ganache.