How Important Is Oven Rack Position?
Someone emailed this question to me a while back: Which oven rack position do you use for different applications? For instance, baking cakes, cookies, etc; braising, breads, roasting meats, etc."¨ Thanks
I realized that I had never really given much thought to which rack to use. I usually just follow the directions in the recipe, such as "Set rack in the bottom third of the oven," or "Bake in the middle of the oven." If it's something that I rarely think about, I figure that it's something that most other home cooks don't really pay attention to.
But what if we don't have a recipe, or if a friend writes down a recipe for us and doesn't say what rack to use? Or maybe we just want to reheat some casserole. Then what?
Obviously, oven manufacturers wouldn't make the racks adjustable if it weren't a useful feature. And that's where this response comes in. If we know a little about how ovens heat, we can use those adjustable racks to their full advantage.
How Ovens Work
Most ovens are insulated metal boxes that contain two heating elements, one on the top of the oven and one on the oven floor. During preheating, both elements heat up, but when in baking mode, all the heat comes from the bottom. The bottom heating element cycles on and off to keep the temperature at an average of what you've set temperature for. For example, if you set your oven at 350F, the temperature can fluctuate from about 325F to around 375F, but the temperature over time averages out to 350F.
When the heating element is on, intense heat is generated. Since heat rises, this extremely hot air rises to the top of the oven where it cools slightly (we're talking fractions of a degree). When the air cools, it falls again, only to be heated by the element again. This sets up a gentle convective current, even without a convection oven. (A convection oven circulates heated air quickly through the use of a fan).
It's Hotter at the Top
Since the oven's heating element does not stay on all the time and only emits intermittent bursts of intense heat, it is actually consistently hotter near the top of the oven. So, as a general rule of thumb, if you need something to brown very well on the bottom, such as pizza or a pie crust, put it on the lowest rack.
If you want something to brown well on the top, such as a casserole, put it on an upper rack. The middle rack is truly the happy medium, applying fairly consistent heat from the top to the bottom of whatever you're baking.
One thing to consider with middle-rack cooking is how deep the cooking vessel is. Do you want the center of the food in the middle of the oven, or do you want the base of the vessel in the middle of the oven?
If you're baking a 2" cake, it's fine to put the pan on the middle rack. If, however, you are baking a Bundt-type cake, where the finished cake will be 4" thick, it's best to put the pan in the bottom third of the oven. This allows the center of the cake to be in the oven's center.
Adjusting Along the Way
Also, there is no rule that says you can't move items from one rack to another during baking. Let's say you're baking an apple pie, and you want to make sure that the bottom gets crisp and also that the filling cooks all the way through.
You can start baking with the pie on the bottom rack, and after a few minutes, move it to the center rack to finish baking. If the pie is almost done but you'd like it to brown a bit more, just move it up into the top third of the oven.
Here I should note that you should never move an oven rack that has a baking dish or pan on it. For safety's sake, it is best to adjust the racks before pre-heating the oven. If you have to move a rack once the oven is hot, make sure to use oven mitts or thick oven pads, and use both hands to reposition the rack. (Not recommended)
Using Both Racks
Of course, ovens are also designed so that both racks can be used at once. When baking cakes and cookies, for example, you can certainly bake two pans at once. For cakes, if the pans are small enough that there is at least an inch of air space between the pans and the oven walls and in between the pans, you can bake them on the same rack.
If there is not enough room, you will need to bake on two racks. Since cake batter is less stable than cookie batter before it starts to "set up" in the oven, do not move the pans until the cakes are almost done, and then carefully rotate the pans.
For cookies, the ones on the lower rack will brown more quickly on the underside while the cookies on the higher rack will brown more quickly on the top. Rotating the sheets half-way through the baking process helps all the cookies to bake evenly.
Placing one cookie sheet on top of another sheet can help to insulate the bottom so that the bottoms of your cookies don't brown too much. You can also purchase those double-layered "Airbake" pans to help with that.
How About Broiling
If using your oven for broiling, the bottom element does not come on at all, but the top element provides constant radiant heat. The closer to the element the food is, the more quickly it will brown.
If broiling a very thin piece of meat--maybe 1/2" or so, you'd want to have it on the top rack, as close to the heat as possible. For thicker cuts--maybe an inch--set the rack lower. This allows the heat to evenly penetrate the meat, making sure the center cooks before the outside gets overly brown.
Rule of Thumb
These are the basics of oven rack position. A good rule of thumb is that, if it is more important for the bottom to brown while baking, place the rack low. If it is more important that the top brown, place the rack high. Of course, the converse holds true, as well: if the top of your pie is browning too quickly, place it on a lower rack. If the bottoms of your cookies are browning too quickly, put them on a higher rack.
For most baking, positioning the food in the center of the oven is ideal. Just remember for the center of a large turkey to be in the center of the oven, you'll have to place the rack lower than if you're roasting a pork tenderloin or baking cookies.