Don’t you hate it when your pizza, pie, or casserole is ready to bake, but your oven isn’t hot enough? Preheating is a necessary step to ensure even baking, but how can you tell when your oven is hot enough?
In some electric oven models, the preheat indicator on the LCD display will shut off when the oven is done preheating. If your oven doesn’t have an electronic display, you can use an oven thermometer to determine whether or not your oven is preheated to the right temperature.
In this guide, I’ll explain in greater detail how to tell what your oven is done preheating. I’ll also describe whether or not preheating is an absolute must.
What Is Preheating an Oven?
In many baked recipes, the author will tell you to preheat your oven to 350°F, 375°F, or upwards of 400°F, depending on what you’re making. So, what exactly does preheating an oven mean?
Preheating means turning on your oven to the desired temperature—e.g., 350°F—and waiting for a period of time until the oven has reached the set temperature.
Nearly all baking recipe instructions will tell you to preheat your oven before placing your food inside. This is done to ensure that your food, as well as its baking vessel, receives the same level of heat from start to finish.
What Happens When You Don’t Preheat an Oven?
What if you skip this vital step? Is it going to affect the outcome of your food?
Well, not necessarily. Although preheating an oven ensures even cooking throughout the baking process, you might find out that it doesn’t play a significant role in the recipe’s outcome. Some dishes, such as pies in blind-baked shells, can withstand the gradual rise in temperature inside an oven without losing flavor or texture. However, other types of foods, like pizzas, require a super-hot environment to achieve the perfect balance between crispy and chewy.
However, there’s another factor to take into account before you decide to skip the preheating phase. A preheated oven will immediately start cooking the food instead of warming it up. If you place your food in a warming-up oven, you increase its exposure to the danger zone.
In food terms, the danger zone is the temperature range (40 to 140°F) in which foodborne bacteria and other nasty creepy crawlies thrive and multiply. While it’s safe to leave food at room temp (around 75°F) for up to 2 hours, it’s advised that you limit heat or cool your food down to keep it out of the danger zone. Placing food in an oven will prolong its exposure to the danger zone since it takes the center of the dish longer to heat up.
So, to sum up, you should always preheat your oven, even if your cookbook doesn’t remind you. If you don’t do it to keep foodborne pathogens from wreaking havoc on your gut, at least do it to promote even crisping and browning!
How Do I Know if My Oven Is Preheated?
Without the proper tools or indicators, figuring out when your oven has reached its set internal temperature can be tricky.
The good news is that many modern electric oven models come with an LCD display that informs the user when the oven is preheating and when it’s done. Depending on the oven, a “PrH” abbreviation might show up on the display, letting the user know that the oven is still warming up. When the PrH indicator shuts off, the oven is ready to bake.
But what if you have a gas range or your electric oven doesn’t come with a preheating indicator? That’s where an oven thermometer comes into play.
A simple yet effective oven thermometer, such as the Taylor Dial Oven Thermometer, will tell you what the oven’s internal temperature currently is. When the oven reaches your desired cooking temperature, you can rest assured that it’s ready to bake.
Do I Need an Oven Thermometer?
Here’s the thing about the built-in thermometer in your oven: it’s not 100% reliable.
The oven’s thermometer probe, which registers the internal temperature of the oven, is usually situated at an awkward place—e.g., the back or the floor. In addition, the probe might be touching another part of the oven, throwing its temperature reading off by around 50°F. Sadly, even high-end electric oven models are not immune to this problem.
When measuring the internal temperature of an oven, you want the thermometer to be as far away from the walls, ceiling, and floor as possible. The best way is to get an external oven thermometer and place it in the middle of the center rack.
How Long Does It Take an Oven to Preheat?
Alas, I cannot give you a definitive answer.
Some ovens take as little as 10 minutes to heat up to the set temperature, while others will take 20 minutes or so. On average, an oven will take between 12 and 15 minutes to preheat, but you this is only a rough estimate.
Also, there are some oven models with “hidden” baking elements. The coils are hidden behind the oven’s walls and beneath the floor to prevent accidental third-degree burns when inserting and taking food out of the oven. Unfortunately, due to the physical barrier between the open space in the oven and its heating elements, it can take considerably longer for the oven to reach the desired baking temperature.
While there’s no such thing as preheating for too long, doing so will waste energy. The good news is that preheating an oven for “too long” will not affect the outcome of your baked dish. So, it’s always better to let your oven run for a bit longer than normal that to insert your dish at the precise time the oven is up to temperature.
Again, an external thermometer is your best friend. It will reliably tell you whether or not the oven has come up to temperature. What you can do is time how long it takes and use that time frame as a reference in the future.
How to Preheat an Oven Quickly
Waiting for 10 to 20 minutes for your oven to come up to temperature sounds like an eternity, especially when pizza, pie, or macaroni and cheese is involved. The good news is that there’s a neat trick you can try to reduce how long it takes for your oven to preheat.
If you want to preheat your oven in less time, simply turn on the broiler element and let it run for 3 to 5 minutes. Broilers typically reach temperatures of up to 550°F. After 3 to 5 minutes, shut the broiler off and turn on the baking elements. These elements will have an easier time increasing the temperature of the rest of the oven and possibly reduce the overall preheating time to a fraction of its original length.
However, this trick only works with ovens that have ceiling-mounted broiler elements. Gas ovens typically have a pull-out broiler cabinet underneath the oven’s floors, so you can’t pull off this helpful kitchen hack.
Can You Put Cold Food in an Oven?
It depends on the recipe. For casseroles, meatloaf, and dough, you should allow the food to come back up to room temperature after chilling. Also, if you’re intending to put a glass baking dish into the oven, the sudden temperature change from cold to hot can cause thermal stress to the dish and ruin its structural integrity.
However, baking chilled cookie doughballs on a stainless-steel cookie sheet is completely fine. In fact, some say that baking chilled cookie dough produces a crispier exterior and a consistent chewiness in the center.