Convection ovens use fans to move hot air around, which helps speed
cooking times. Generally, food prepared in a convection oven cooks 25
percent faster than it would in a conventional oven. The rapid moving
of hot air also browns foods more evenly, locks in juices on roasts,
and eliminates the hot spots found in conventional ovens.
To convert conventional oven recipes for a convection oven - heat the convection oven to 25 degrees F lower than the recipe calls for. Also, expect food to be done in 25 percent less time than it would be in a conventional oven. Start checking for doneness about 10 minutes before the food is scheduled to be done, and even sooner for foods that cook for extended periods, such as roasts.
To choose the pans - no special pans are required for convection cooking, but baking sheets and roasting pans with low sides will allow food to cook more quickly and brown more evenly.
To roast meats by convection - place the meat directly on the oven rack and position a drip pan on the lowest rack. The forced hot air will seal the outside surface of the meat to help lock in juices. Thus, the meat will drip less and brown more evenly, so you won't need to turn it or baste it as you would in a conventional oven.
Cooking baked foods by convection - a convection oven will dry out the surface of food, creating a thicker crust on baked foods. As a general rule, use convection for breads, pies or other foods where a thicker crust is desirable. When no crust is desirable, as in cakes and rich desserts that have a high moisture and fat content, it's best to stick with conventional oven cooking. Pastries and meringues cooked by convection could set at a tilt due to circulating air currents.