Recipes engineered for perfection—what exactly does that mean? We take you inside Cook’s Illustrated’s science experiments.
Crunchy edges, chewy centers, and big butterscotch flavors—that chocolate chip cookie framework sounded pretty sweet to us. As it turns out, perfect cookies have a lot to do with how the sugar in the recipe is treated.
Sugar that is dissolved in liquid before baking caramelizes more readily than sugar that simply melts when exposed to the same amount of heat. What would happen if we rested our cookie batter after we added the sugar to allow more of the sweet stuff to dissolve before going into the oven?
We prepared two batches of our Perfect Chocolate Chip Cookies. Dough from the first batch went straight from the mixing bowl onto the baking sheet; the other batch rested (with the occasional whisking) for 10 minutes (or the amount of time it takes for the sugar to dissolve) after we combined the sugar with the recipe’s liquids. Cookies baked from the rested batter boasted not only richer, deeper flavor but also crisper edges.
Why was this? It turns out that dissolving the sugar in liquid provided by the melted butter, vanilla, and egg (accelerated by whisking and resting) affects both flavor and texture. Dissolved sugar breaks down more quickly from crystalline sucrose into glucose and fructose, which caramelize at a lower temperature to form many rich, new flavor compounds. As the dissolved, caramelized sugar cools, it takes on a brittle structure. In our cookies, this brittle texture is more evident at the edges. Why? As the oven burns off moisture from the cookie perimeter, the remaining moisture gets pulled into the center, keeping it chewy. Did you have any idea that science could be so sweet?
MAKE IT NOW: Our recipe for Perfect Chocolate Chip Cookies is free through March 30, 2013.