Fresh, unsalted butter is the philosopher's stone of classical Western cuisine, variously lending texture, loft, sheen, and flavor to a cooked dish or pastry when it's added at the right moment and in the right way. Here are six time-honored techniques worth mastering.
1. Creaming butter is a favorite baker's trick: whipping together butter and granulated sugar when making cake batter introduces air and ensures a light, fluffy crumb. Patience is key; don't stop whipping until the mixture is light and silky.
2. Sauces can be finished with butter, to luxurious effect, with a technique called mounting: for a rich, glossy, butter-mounted sauce, add pieces of well-chilled butter to the heated sauce and rotate the pan steadily, allowing the butter to emulsify slowly.
3. French pâtissiers have long used a technique called fraisage to achieve pastry crusts with a remarkably delicate texture: after mixing butter and flour for a pie crust dough, smear the mass repeatedly with the heel of your hand. This causes the dough to form more-intricate layers when it bakes.
4. Putting butter underneath a chicken's skin produces juicier meat and crisp, browned skin. Before roasting, gently loosen the bird's skin from the flesh; then reach under the skin with a spoonful of soft butter and slide the butter inside. It's a good idea to rub butter on the outside of the bird as well.
5. Making your own compound butter—fresh butter that's been softened, then mixed with minced herbs, spices, or other flavorings and chilled—and keeping it on hand for topping roasts or grilled or sautéed foods will brighten and enhance all sorts of dishes. Parsley, shallots, lemon juice, salt, and pepper are a classic combination, but the variety of ingredients you can use—from anchovies and capers to chipotle chiles, lime juice, and cilantro—is virtually infinite.
6. Finishing sautéed items with a basting of butter is an easy way to impart flavor and sheen; just before your meat or fish is done, tilt the pan slightly and add a pat of butter near the pan's edge, then spoon the melted butter over the fish or meat.