Better Cooking Through Convection

Conventional oven(left) Convection oven(right)

Help! I've got a new convection oven, and I don't know what to do with it." I hear this plea a lot from cooks who have just redone their kitchens, and also from people who are intrigued about convection cooking but aren't sure what the big deal is. The answer is simple: You can cook just about anything in a convection oven, and while learning to use one certainly isn't a big deal, the results you get—evenly cooked cookies, crisp pastry, and juicy, well-browned meats—are.

To get comfortable with a convection oven, you just have to start using it. The easiest way to do this is to experiment with your favorite recipes by cooking them at a slightly lower temperature and for a slightly shorter time than you normally would. But before you do that, or before you follow through with your plans to buy a convection oven, read on to learn how these ovens work, how different models vary, and what kind of results you can expect.

A convection oven circulates hot air with a fan

Unlike conventional radiant (also called thermal) ovens, convection ovens have a fan that continuously circulates air through the oven cavity. When hot air is blowing onto food, as opposed to merely surrounding it, the food tends to cook more quickly. A short version of the scientific explanation for this is that moving air speeds up the rate of heat transference that naturally occurs when air of two different temperatures converges. To help understand this, consider wind chill: When cold air blows against you on a blustery winter day, you feel colder more quickly than you do on a windless day of the same temperature.

This acceleration effect is one reason for the superior results you get from convection. The rush of heat speeds up the chemical reactions that occur when food cooks. The butter in a pie crust or a croissant releases its steam quickly, creating flaky layers. The skin of a roasting chicken renders its fat and browns more quickly, so the meat cooks faster and stays juicier. The sugars in roasting vegetables and potatoes begin caramelizing sooner, creating crisp edges, moist interiors, and deep flavors. Overall, food cooked in a convection oven is usually done about 25% faster than it is in a conventional oven.

Another benefit of all this circulating hot air is more even cooking. In a conventional oven, baking three racks of cookies at the same time is asking for trouble (see "The cookie convection test," below). The cookies on the bottom rack closest to the heating element, as well as those on the top rack where hot air rises, will be overcooked before the cookies on the middle rack are done. Convection cooking, with hot air moving all around the oven, can eliminate hot and cool spots for more even cooking. And when you can bake 50 cookies at once, your oven is operating a lot more efficiently. This even heating feature gives a great boost to roasts, too. For instance, if you roast a turkey in a convection oven, it will brown all over, rather than just on top (roasting the turkey on a rack in a low-sided baking dish or on a rimmed baking sheet helps to encourage this). It will also be done much more quickly.

Not all convection ovens are "true convection"

The extent to which you get these marvelous results depends a lot on the particular convection oven you're using. The best—and most efficient—convection ovens blow heated air into the oven cavity. This means they have a third heating element (in addition to the usual top and bottom elements in a radiant oven) located near or around the fan in the back of the oven. This element heats the air to a uniform temperature before it enters the oven cavity. In many ovens, the third heating element is covered by a baffle, or a panel, which channels air sucked in by the fan past the heating element and back out into the oven.

The appliance industry generally calls this type of oven "true convection," "third-element convection," or "European convection" (first popularized in Europe), so these are the terms to look for when shopping. In an effort to distinguish themselves, however, some manufacturers have come up with their own names. Dacor, for instance, calls its technology "Pure Convection" because its third-element convection also uses a special filtering system that prevents odors from being transferred from one item to another cooking in the same oven.

Convection ovens without a third heating element generally cook less evenly. In the worst examples, this type of oven will have a fan mounted on the outside of the oven and will actually blow unheated air into the oven cavity, randomly mixing up hot and cold air. In most of these ovens, though, the fan is mounted on the inside of the oven cavity, but the air blowing around the food won't be a uniform temperature. With the bottom radiant element fully heated, the oven will have hot and cool spots.

You'll find most "true convection" ovens in built-in wall ovens or slide-in ranges, not countertop models. If you're looking for the benefits of convection cooking, you should really upgrade your range or wall ovens rather than buy a countertop convection oven. Full-size ovens generally have better circulation and ventilation, and they may include a filtering system. They're usually self-cleaning, too. If, however, you're short on space and looking for extra oven capacity, a countertop convection oven might be right for you. Some of the better models do have heating elements integrated with the fan.

Finding a "true convection" oven

If you've had convection in your home oven in the past, you might have been underimpressed with it. Just in the last few years, manufacturers have really caught the "true convection" bug, and home ovens are much better for it. Now there are so many ovens with convection features on the market that I couldn't begin to name them all. I do know that Amana, Dacor, GE, Gaggenau, Frigidaire, Kenmore, Miele, KitchenAid, Thermador, and Viking all manufacture electric, self-cleaning ovens that feature third-element convection. Each manufacturer has many different models of oven, though, so you must inquire carefully to make sure the oven you're eyeing has the goods. If you've got your heart set on a professional range, you might have to give up true convection, as many of these ranges didn't feature it until recently, and some still don't. Also, gas ovens generally don't offer true convection. (This doesn't mean you can't have a gas cooktop; many manufacturers now offer "dual-fuel" ranges.)

Also, ovens are becoming so highly specialized that true convection is only the beginning. Most ovens are designed to let you turn convection on and off as you please. But some go further and allow you to use the convection element with just the broiler, or just the baking element, or with either of these heated to a lesser or greater temperature. Gaggenau has an oven with nine cooking combinations. Other manufacturers, including Thermador and GE, offer ovens with a hidden radiant element in the bottom of the oven so you can cook pizza and breads directly on the heat source with the convection functioning, too. Or if you want a professional-style all-convection all-the-time oven, Wolf now offers one designed especially to be built into home kitchens. Every manufacturer has an angle.

To get familiar with the options, get on the Internet and then head for an appliance store. Built-in or slide-in convection ovens and ranges start at about $1,500.

Try pastries, pies, roasts, or vegetables in the convection oven

Once you decide what type of convection oven you're going to use, you can begin to think about what you'd like to cook in it. I first got excited about convection ovens when my mother started cooking in one 20 years ago. My father brought home one of the first Farberware countertop convection ovens, and my mother discovered it produced especially delicious roast chicken and roast potatoes. Later, when I began working in professional kitchens, I learned that a convection oven can cook a lot of things well. I began to rely on it for the tastiest, well-caramelized roasted vegetables. I cooked crisp tart crusts, juicy beef tenderloins, and even perfect frittatas in a convection oven. The pastry chefs I worked with used the convection oven to bake flaky croissants every morning.

When I began to research this topic, I was curious to know how other cooks felt about convection cooking and what tips they could offer. I discovered that many pros have had limited experience with home convection ovens but have used them in professional kitchens. Now that so many manufacturers are including true convection in home ovens (and many chefs are upgrading their home kitchens), that will probably change. Nevertheless, I did get some valuable advice and interesting opinions, which I hope will help you in considering convection for your kitchen.