Braising, searing, roasting, simmering—it’s all cooking, obviously, but each technique yields a uniquely delicious result. The question is, why?
Cooking, by simple definition, is the application of heat to food. But all heat is not created equal. In the kitchen, there’s a big difference between moist heat and dry heat. Whenever you add a water-based liquid to the pot or pan—for instance, when you simmer, boil, steam, or braise—you’re cooking with moist heat. If you don’t add water—when you sear, sauté, fry, roast, or grill—you’re cooking with dry heat. And when you understand the different effects moist and dry heat have on food’s flavor and texture, you’ll be that much closer to getting the results you want from whichever cooking technique you choose.
Dry heat creates new colors and flavors
If you want the exterior of your food to be browned or crisp, dry heat is the only way to go. Dry, relatively high heat spurs molecular changes in the amino acids and sugars on the surface of food, turning them brown, sweet, and crisp. Allowed to progress unchecked, these browning reactions can take the exterior of your food from deliciously golden brown to bitter and burned. So the challenge of all dry-heat cooking methods is getting food cooked through before the exterior overcooks. The key is to choose the right dry-heat technique for your ingredients (see the table below), or to combine two methods, such as searing first and then roasting.
Searing, sautéing, and pan-frying. When food hits a very hot, oiled pan, surface moisture on the food quickly evaporates, and a nice brown crust begins to form on the surface of the food. A common pitfall with these dry-heat methods is overcrowding the pan, which hinders evaporation, causing food to steam in its own juices instead of brown.
The ideal foods for these stovetop techniques are fairly thin, tender cuts of meat (chicken breasts, steaks and chops, or fish) or uniformly chopped or sliced vegetables. If the food is too thick, you risk burning the outside before the inside is done—the surface of the food receives intense heat (up to 450°F) by being in direct contact with the hot pan, but heat travels comparatively slowly to the center of the food. Tony Rosenfeld tackles that problem in his story Sear, Roast & Sauce, where he sears thicker steaks, chops, chicken breasts, and salmon fillets on the stove and finishes cooking in the gentler heat of the oven.
Roasting and baking. When we bake or roast, we surround food with hot, dry air (300° to 500°F), which heats the surface, evaporates moisture, and allows browning to occur. It takes much longer to roast or bake food than to sear or sauté it because air is a poor heat conductor (you’ve probably noticed that you can put your hand in a 400°F oven but not in 400°F oil or in boiling water). This makes roasting ideal for cooking large cuts of meat or whole vegetables.
Deep-frying. This might seem a lot like boiling, but submerging food in hot oil is actually considered a dry-heat cooking method. Hot oil gets far hotter than boiling water, so it’s able to dry out the surface of food and brown it.
Grilling and broiling. When you grill over glowing embers or slide food beneath a fiery broiler, infrared heat cooks the food. The temperature of glowing coals and broiler elements can be off the charts—from 2,000° to 3,000°F—so you can quickly achieve amazing browning and flavor. But as with searing and deep-frying, if you’re not careful, your kebabs or steaks will be charred outside and raw inside, so these techniques are best for thin, tender cuts of meat and quick-cooking vegetables.
Moist heat brings out foods' natural colors and flavors
The most obvious feature of moist-heat cooking methods is the absence of browning, which is triggered by dry, high heat. Consider the differences between boiled and roasted potatoes. When you eat food cooked in moist heat, you taste the inherent qualities of the food, as opposed to flavors created by the cooking method itself.
Cooking in water: boiling, simmering, poaching. Once water reaches its boiling point, it doesn’t get any hotter (except in a pressure cooker). Although 212°F water is hot enough to tenderize food by breaking down plant cells and complex protein molecules, it’s not hot enough to kindle the chemical reactions that cause browning. One big advantage to cooking in water is speed; water conducts heat well and cooks food quickly. A few minutes in boiling water is all it takes to cook dense vegetables like carrots or cauliflower florets (in a 400°F oven, they take much longer).
With moist heat, burning isn’t an issue, but it’s still possible to overcook food, especially by boiling. Boil cauliflower too long and the cell walls will collapse, leaving you with pallid mush.
Most food is considered cooked when its interior temperature reaches somewhere between 125° and 170°F. In his book, The Curious Cook, Harold McGee demonstrates that if you can keep the cooking liquid’s temperature at the food’s ideal cooked temperature, there’s no risk of overcooking. That’s why it’s kinder to simmer some foods in water at 180°F or even poach at 160°F. If you drop a chicken breast into boiling water, the exterior will be tough and dry by the time the meat is cooked through, but if you poach the breast, it can become succulent. Unfortunately, it’s easier to maintain a rolling boil than a 160°F poach, so stove-side vigilance and a thermometer are required.
Cooking in water vapor: Steam, which is 212°F or hotter, envelops food in moisture and cooks it quickly but gently. Steam can enhance the natural qualities of vegetables, and it cooks delicate fish without washing away their flavors or subjecting the flaky flesh to the agitating bubbles in simmering or boiling water. And if you want rice or couscous to be exceptionally fluffy instead of soggy, try cooking them with steam.