Another very good question, since a recipe for macarons — practically speaking — can be as few as four or five lines long. Strange then that most magazine features on macarons go on for pages as authors labor to explain the picayune nuances of getting a macaron just right. Some of them get downright mystical. Turn your bowl of stiffened egg whites upside down for five seconds. Knock your sheet pans together three times. Stand on one foot while reciting Pierre Hermé’s middle name backwards twice. So OK, I made that last one up, but only to underscore how downright comical these recipes can be. Read them and several things become abundantly clear. Primarily, that there’s a broad and unhealthy obsession with creating the “perfect” Hermé macaron. Second, that there’s very little understanding among most home bakers about what macarons are and how they work.
As I’ve mentioned, macarons are simple meringue cookies, not unlike the little meringues that many of us grew up with. You know, those little blobs of sweetened egg white foam, often studded with chocolate chips. They’re great. What makes macarons different is that they contain a high amount of ground nuts, which introduce a good deal of oil into the egg white foam and in the process create a very different texture: a shiny, eggshell-thin crust which yields to a soft and slightly gooey interior.
As I’ve discussed exhaustively in the past, foam and fat are natural enemies. Put a little oil or fat into a bowl with unbeaten egg whites and you’ll have a job whipping the mix up into a stable foam. The reason in a nutshell: because fat molecules compete with protein molecules on the surfaces of air bubbles, undermining the fairly stable “films” that egg proteins create, and which hold the foam up. However there’s nothing that says you can’t add fat after you’ve whipped an egg white foam up, for once the protein meshes have formed, they do a pretty good job of crowding out the fat molecules, keeping the bubbles from popping. This is the science behind soufflées, buttercreams…and macarons.
Macarons (at least in the French version of the recipe) begin with an egg white foam to which sugar is added, both to sweeten and stabilize it. Once this basic meringue is created, a mixture of ground nuts (classically almonds) or nut flour are added, along with more sugar. The mixture is then folded together until the right consistency — not too stiff, not too runny — is arrived at. This step, according to most recipe writers, is the where all the magic and mystery is in the perfect macaron. I’m not necessarily denying it, however I will say that there’s more to a successful macaron than just the mixing, as I’ll discuss in the next post.