In the test kitchen, we use different cooking oils to suit the flavor and cooking temperature requirements of the recipe at hand. Here are the oils we commonly use:

Vegetable and Canola Oils

Loosely speaking, a vegetable oil is an edible oil made from any number of “vegetable” (as opposed to “mineral”) sources, including nuts, grains, beans, seeds, and olives. In the more narrow confines of recipe writing, it usually refers to one of the more popular brands of cooking oil in the supermarket whose front label reads “Vegetable Oil” in large type; on closer inspection of the small type on the back label, you’ll usually find that these generic vegetable oils consist of soybean oil. Canola oil is prepared from rapeseed oil.

Vegetable oils have high smoke points and almost no flavor, so we use them interchangeably in the kitchen. These oils are fine for quick deep-frying but will begin to break down and create unpleasant flavors after about 15 minutes. We also use these oils for shallow-frying, sautéing, and stir-frying, as well as in dressings with strong flavors.

Olive Oil

Also called "pure" olive oil, this product adds some—but not too much—fruity flavor to foods. We especially like to use olive oil for dishes with Mediterranean flavors. We use it to brown meats, to start soups and stews, and in sauces and dressings with strong flavors.

Extra-Virgin Olive Oil

Although many cooks never use extra-virgin olive oil for cooking (because its flavors dissipate when exposed to high heat), we like its strong flavor in dishes that are cooked quickly. We also use extra-virgin olive oil to dress blanched or steamed vegetables and to drizzle over soups and grilled foods; additionally, it's our first choice in most vinaigrettes.

Toasted Sesame Oil

The potent flavor of toasted sesame oil (sometimes labeled Asian sesame oil) fades quickly when exposed to heat, so we like to add this oil to Asian-inspired dishes in the final moments of cooking. We also use toasted sesame oil in dressings, sauces, and marinades. This oil is highly perishable, so store it in the refrigerator.

Peanut Oil

Refined peanut oil, such as Planters, has a neutral flavor and high smoke point, making it our first choice for deep-frying chicken, fish, and potatoes. Best of all, it doesn't break down and impart off flavors, even with prolonged heat—a problem we've had with other oils. Unrefined peanut oil, which has a nutty flavor that we like in stir-fries, is sold in small bottles for a hefty price, making it inappropriate for frying.