First, let’s get a rough idea of the structure of muscles. Muscle cells are long and elastic and come bound together in protein sheaths called fibrils. These fibrils are arranged lengthwise into bundles — like the filaments in a fiber-optic cable — which give meat its distinctive grain. As meat heats up, the proteins that surround these bundles change shape and contract, causing those bundles to squeeze tighter and tighter, eventually forcing out juices. Just like toothpaste out of a tube, once the juices are squeezed out, there is no way to get them back in. This is why overcooked meat ends up dry, even when cooked in a moist environment.
The salt in a brine dissolves some of the proteins in those bundles. A weaker protein structure means less squeezing, which leads to juicier cooked meat. Moreover, because a salty brine works its way from the outside in, its greatest effects will be on the outermost layers of muscle fibers, the areas most prone to overcooking.
While the advantages of soaking a turkey in a liquid brine are obvious, especially in lean breast meat, there are some disadvantages. The first is space. In a restaurant kitchen with a walk-in refrigerator, space isn’t an issue, but at home, finding a vessel that can fit a whole turkey and keep refrigerator-cold for a couple of nights is not as easy. I used to resort to brining turkey inside a cooler, which I’d keep chilled with ice packs that I’d change out every six to eight hours. (Ice packs were necessary because using plain ice would end up diluting the brine as it melted.)
The second disadvantage is that liquid brine can dilute the turkey flavor. A brined turkey may taste juicier, but it also tastes watered down, as there is an inevitable exchange of liquid between the turkey and the brine during its extended soak.
The solution? Ditch the solution. These days, I use a salting method known as “dry-brining,” which I learned from the chef Judy Rodgers’s recipe for the roast chicken she served at Zuni Café in San Francisco. All you have to do is salt your turkey inside and out with coarse salt (it works best if you get some of the salt between the meat and skin on the breast, but even salting over the skin will help), place it uncovered on a rack in the fridge, and let it rest for a day or two. Initially, the salt will draw out liquid from the turkey — you’ll see it start to bead up on the surface within minutes. The salt then dissolves in this liquid, creating a super-concentrated brine that will then start to work its way back into the bird, dissolving muscle proteins as it goes.
In testing I did for my Food Lab column at Serious Eats, I found that dry-brined poultry as well as traditionally brined birds retain about 35 percent more moisture than unbrined poultry. But one advantage of dry-brining is that the turkey’s flavor remains undiluted by excess water.
While brining is key, temperature management is even more so. The goal is to get the dark leg meat to cook faster than the lean breast meat. The traditional method of roasting a turkey — placing it on a rack in a deep roasting pan — accomplishes the exact opposite. A deep roasting pan reduces the flow of hot air around the thighs and back of the turkey, while the breast meat remains elevated above the rack, speeding up its cooking. By the time the leg meat has reached the requisite 170 to 180 degrees, the breast meat is hopelessly overcooked.