From America's Test Kitchen
Most of the focaccia we see in the States is heavy, thick, and strewn with pizza-like toppings. We wanted a lighter loaf, crisp-crusted and airy on the inside and topped with just a smattering of herbs.
To start, we focused on flavor. To get the benefits of a long fermentation with minimal effort, many bakers use a “preferment” (also known as a “sponge,” “starter,” or biga in Italian): a mixture of flour, water, and a small amount of yeast that rests (often overnight) before being incorporated into the dough. We followed suit, but the interiors of the loaves weren’t as tender and airy as we wanted. We wondered if our standing mixer was developing too much gluten (the strong, elastic network of cross-linked proteins that give bread its crumb structure). Instead we turned to a more gentle approach, one we learned while developing our Almost No-Knead Bread. In this method, a high hydration level (the weight of the water in relation to the weight of the flour) and a long autolysis (the dough resting process) take advantage of the enzymes naturally present in the wheat to produce the same effect as kneading.
This method worked to a point—our loaves were light and airy, but squat. To improve the structure, we turned the dough (folding in the edges of the dough toward the middle) at regular intervals while it proofed. But to cut back on the long proofing time (three hours) and hasten gluten development, we followed the advice of research, which suggested holding back the salt when mixing our dough, adding it in later. (Salt inhibits flour from absorbing water and slows down the activity of the enzymes responsible for developing gluten.) The results were dramatic—we were able to shave an hour off our proofing time.
To give our loaves a flavorful, crisp crust, we oiled the baking pans and added coarse salt for flavor and an extra crunchy texture. This focaccia was a revelation: crackly crisp on the bottom, deeply browned on top, with an interior that was open and airy.
Makes two 9-inch round loaves
If you don’t have a baking stone, bake the bread on an overturned, preheated rimmed baking sheet set on the upper-middle oven rack. The bread can be kept for up to 2 days well wrapped at room temperature or frozen for 2 months wrapped in foil and placed in a zipper-lock bag.