My latest piece over at Lucky Peach is filled with very graphic information about making meringue. I feel like it should come with a warning label, since even I started to get cross eyed after writing the word “denatured protein” for the umteenthousandth time.
My friend Marc Shermerhorn took one of my baking classes and chose the recipe with the fewest ingredients, thinking it would be the simplest. Instead, he discovered that the recipes with the fewest ingredients are often he most complicated, because they rely on the precise interaction of the few ingredients involved. Meringue is right up Marc’s alley, with little more than egg whites and sugar. However, the way we combine them dictates the ultimate texture, and I’ve got every detail covered for you guys.
The kind of meringue you get from a bakery—the impossibly light cookie, so brittle that it crackles at first bite and dissolves immediately, leaving behind only an echo of flavor—is just one version of what “meringue” is. Meringue, whipped egg whites and sugar, is one of the most fundamental techniques in pastry. It’s the base for desserts like soufflés, mousses, semifreddos, marshmallows, chiffon cakes, and some cookies, to name just a few. As such, it is crucial for a pastry chef to master—and is a useful technique for every home cook to have in his or her arsenal.
First, some science. There are three generally observable states of matter in the physical world: liquids, solids, and gases. Meringue is a foam, which forms when a gas is suspended in a liquid or solid.
Combining states of matter is not particularly difficult, but encouraging them to stay combined is. When creating a stable foam, two things need to be present: a foaming agent, which traps the air, and a stabilizing agent, which keeps the air in place. In a meringue, albumen, the family of proteins in egg whites, acts as the foaming agent. Albumen has dual-action surfaces. Some elements are hydrophilic, meaning they love water, and others are hydrophobic, meaning they fear water and will grab onto anything else present to avoid coming in contact with it. When the egg whites are whipped, the hydrophobic parts of the proteins search for air, seeking refuge from water. When enough proteins cluster around an air bubble, hiding their hydrophobic parts inside it, the bubble will become completely surrounded by proteins, and in turn, trapped.
Though the hydrophobic parts of the albumen have trapped an air bubble, the hydrophilic parts are attracting water. The proteins themselves aren’t durable enough to hold the heavy water molecule steady and keep their hydrophobic parts inside an air bubble at the same time. Think of the proteins like little teeter-totters with a water balloon on one side, and a balloon filled with air on the other. If you’ve ever whipped plain egg whites, you’ll know that they will begin to deflate almost immediately after you stop the motion of the whisk.
This is why we need a stabilizing agent, and in meringue, we use sugar. The sucrose molecules act to stabilize the foam, bonding with the proteins and water, gluing everything in place and helping meringue holds it’s shape. If sugar is added incorrectly, however, it can act as a destabilizing agent, which brings us to the first tip to making a good meringue……