Convection is a type of appliance feature in which a fan pushes the heated air around the inside of the oven, creating a more evenly heated space. Once a rare, professional perk, convection fans are now showing up in home appliances such as microwaves and toaster or countertop ovens. Showing up along with these appliances are cookbooks meant for use with convection ovens. If you are using an older appliance that does not have a convection fan, you can convert a recipe for use in a conventional oven.
Add -3.89 degrees Celsius to the convection recipe's cooking temperature. Try -1.11 degrees Celsius if the first batch doesn't seem to bake too well. This is a general guideline to start with for baking.
Use the same temperature but increased cooking time if you are roasting something. For those switching from conventional cooking to convection, Consumer Reports advises decreasing the conventional recipe's cooking time by 25 per cent, so if you're going the other way and converting from convection to conventional, increase the convection recipe's cooking time by 25 per cent for use in a conventional oven.
Test out different temperatures and times by making small versions of the recipe before attempting to cook large amounts, especially for special occasions. Gourmet Sleuth notes that other strategies for converting baking recipes from conventional to convection involve reducing the cooking time at the same temperature, as in step 2, or reducing both the temperature and time by smaller amounts that will vary for individual ovens. To convert from convection to conventional, try reversing these strategies and using increased times and temperatures.