Should You Use Conventional or Fan-Assisted Baking in the Oven?

Conventional (top-bottom) heat sends heat steadily from the top and bottom of the oven, while fan-assisted (convection) mode circulates hot air around the oven, spreading heat faster and more evenly. Because of this, the same recipe can bake in a different time and turn out differently depending on which of the two modes is used; some ovens can use both modes at the same time. As a rule, use conventional heat for a single baking sheet where you want a distinct browned surface, and fan mode when baking several baking sheets at once or when you want fast, even cooking; this preference can shift slightly from one oven brand to another. Which mode suits cakes and pastries? For cakes, cookies and pastries that need to rise, conventional heat is usually the safer choice; the airflow from the fan can push rising batter to one side. Anyone forced to use fan mode should lower the temperature by a 10–20°C / 18–36°F difference from what the recipe states to compensate. Placing the cake pan in the center of the oven helps heat spread evenly in conventional mode. What if you want a browned top? For dishes like pide, börek (savory pastry), or gratins that need a distinctly browned top, conventional heat gives a deeper color than fan mode, since the heat comes directly from above and browns the surface quickly. In fan mode, switching briefly to conventional heat for the last 5 minutes can achieve a similar color. In ovens with a broiler, switching to the broiler for those final minutes works just as well, though it needs to be watched closely. Which mode suits baking several baking sheets at once? Fan mode spreads hot air evenly to every corner of the oven, so it gives far more consistent results than conventional heat when baking two or three baking sheets at once. With conventional heat, the baking sheet on the lower rack usually bakes slower than the one on top, so baking sheets need to be swapped partway through. Even in fan mode, baking sheets placed too close together block airflow, so leave at least 2-3 centimeters between them. How do you adjust temperature and time between the two modes? If a recipe is written for conventional heat and you're baking in fan mode, the temperature is usually lowered by a 10–20°C / 18–36°F difference and the time shortened slightly, since fan mode transfers heat more efficiently and can dry food out if left at the same temperature. The reverse applies too — baking a fan-mode recipe conventionally may need a slightly higher temperature. An oven thermometer makes it easier to see the gap between the dial setting and the oven's actual internal temperature. What general rules help when choosing an oven mode? There's no absolute rule, but conventional heat tends to work better for pastries that need to rise, while fan mode suits baking several baking sheets at once or getting a quick, roast-like result. It also helps to know which mode a recipe was written for; when baking it in a different mode, the temperature and time should always be adjusted. An oven's own manual usually gives more precise guidance on the temperature difference specific to that model; watching the results closely for the first few bakes in a new oven is the most practical way to learn its particular quirks.