I said it before and I’ll say it again: flourless chocolate cake is all in the various techniques. Last night I realized that perhaps the most critical of all of them is the one I haven’t actually talked about yet: folding.
The thing that’s most obvious about a flourless chocolate “cake” is that it’s not really a cake. It’s a custard. The only thing that makes it even vaguely cake-like is the fact that it’s leavened (however slightly). How? By expanding air bubbles, in this case introduced to the mix via the egg foam. Long-time followers of the blog will remember that this is a form of mechanical leavening (the others being chemical and biological) and it requires some delicacy, lest the bubbles break and the cake be conspicuously dense (or at least dense-er).
For most people “folding” is just like stirring, only with a spatula, which it isn’t really. Whenever I fold I try to take the word literally, doing my best to flip the contents of the bowl (or pan) over onto itself. This means getting down under your mixture as best you can and trying to scoop up that which is below and lay it over onto the top, kind of like flipping an omelet. Obviously when you’re flipping an omelet it helps to have a nice broad turner with lots of surface area. Likewise, folding is helped considerably by a nice broad spatula. How broad? As broad as you can fit in your bowl while still being able to work with it is the best answer I have. Mine’s hellacious big, with a handle almost eighteen inches long (I keep meaning to cut it down since it gets in the way a bit). It’s serious folding power.
Here it’s important to note that folding isn’t about complete homogeneity. Streaks are allowable, even desirable, since they’re visible evidence that all your egg bubbles haven’t been broken. It can take a little while to get even to that stage with a flourless “batter”, so be patient and keep folding. Don’t hurry, but don’t be all girly about it either. The aesthetic you’re shooting for is a mix of gentle dexterity and grim determination. Time will eventually break all the bubbles you’ve worked so hard to preserve, so don’t pussyfoot about. Get it folded, get it into the pan, and get it baked, soldier. Good show.