Answer: If you have purchased an oven in the last ten years or so, you probably have a convection oven feature, allowing you to toggle back and forth between convection and regular baking. But that doesn't mean you actually use convection, as it can be confusing. In every one of my classes, someone asks about how to adjust a turkey recipe for convection. It's easy.
A convection oven has a small fan that circulates the hot air inside of the oven. This helps the food cook more quickly, and definitely improves browning. If you aren't using your convection feature, you are missing out of a great technological advance in cooking.
Whenever I am roasting meat or poultry at home or in a cooking class, I always use convection heat, and the results are excellent. Along with improved browning, I find that the pan juices reduce more quickly than conventional roasting from the blowing hot air, so check the pan occasionally and add more stock or water to moisten the juices. This isn't a big deal; every forty-five minutes or so to check is enough attention. Don't obsess over this.
There are two general rules when converting a regular recipe to convection: Reduce the oven temperature by 25F, and reduce the cooking time by about one quarter. So, if you had a turkey recipe for 325F at 4 hours, you would lower the oven to 300F and let it roast for about 3 hours.
The truth is, I never reduce the oven temperature when roasting a turkey or a meat roast. (I do lower the heat by 25F for more delicate items like desserts.) I want the turkey to be a gorgeous burnished brown, so I take advantage of the extra 25F of hot air swirling around the bird. It will not affect the moisture.
As for timing, be flexible. You shouldn't cook with a stopwatch anyway, so use your usual battery of doneness tests for the turkey in addition to timing, such as a meat thermometer, the color of the juices that release from the bird when pierced with the thermometer (they should be golden with no trace of pink), and a pop-up timer (the last is unreliable because it can get glued shut by the juices, but if it works, great).
If your oven has a choice between convection roast, convection bake, and true convection (no wonder you're confused!), check the oven's manual to determine the difference between the settings. They vary slightly with each manufacturer, based on the number of heating elements and the speed of the fan. Basically, the convection roast uses more heating elements (the top and the bottom, for example) and possibly a higher fan speed for more forceful air circulation to cook your not-too-delicate turkey or roast. You would use the convection bake (less direct heat and lower fan speed) for baked goods, and true convection (moderate heat and fan speed, but this uses two fans to create a kind of vortex of air in the oven and many ovens only have one fan) for a middle-of-the-road approach. Bottom line: Use convection roast for your turkey.
Don't forget to let the turkey stand at room temperature for at least 20 minutes before carving, as the internal juices are good and hot and need to redistribute themselves throughout the bird. I let my turkey stand for at least 45 minutes so I can really get a lot of work done on the heating the side dishes, making the gravy, and serving the first course) before carving.
MORE FROM EPICURIOUS.COM:
Recipes & Menus
Epicurious.com's portfolio of dishes for all seasons, cuisines and occasions
The Epicurious Editors' Blog
Food News and Views From All Over
Delicious menu guides for the busy work week
Epicurious Technique Videos
See better approaches to preparing your meals
Assorted galleries featuring pictures and recipes from Epicurious.com