For example, the bottom tends to expand faster and slightly more than compared to the edges. When one side expands more than the other, the baking sheet will bend or twist.
The chances of bending are higher if the baking sheet is too thin or made from poor-quality metal. The stress from the opposing sides causes the sheet to twist or buckle.
After all, when it’s exposed to high temperatures, it makes crackling or popping sounds. When metals are exposed to heat, they tend to expand and change their shape.
The atoms that make up a metal sheet are already moving to some extent. These atoms are fairly stable as compared to those that makeup liquids or solids.
With each atom now occupying a larger space, the metal structure begins to expand. The metal won’t become larger due to heat expansion.
A common solution to stop metals from expanding is to give them extra space. However, because the surface is flatter and smaller, the problem is easier to remedy.
Here we are going to discuss some quick tips that will prevent your baking sheets from bending in the oven. However, if you bought a new one and want to ensure it doesn’t bend, here are some precautionary measures that you can take.
If you do wash it, the cool temperature will put stress on the baking sheet. If the baking sheet is extremely hot, it’s best to put it back in the oven.
Another great tip is to avoid thin metal sheets completely. However, thin baking sheets can also cause the cookies to brown or burn easily.
Aluminum is extremely durable, affordable, and can withstand the oven heat. It has a stable structure that doesn’t warp or crack when exposed to high temperatures.
If it’s not coated with a protective layer, the metal can react with the food. For this reason, make sure to always line the baking sheet with parchment paper.
This way, as the baking sheet heats up, it won’t even react with the food on it. This will offer a large surface area to bake cookies, bread, and pastries.
These sheets are made with a ½ inch lip and are quite affordable. However, insulated baking sheets require a slower time in the oven.
If you’re following a recipe, make sure to modify it according to the baking sheet. Parchment paper prevents the food from sticking to the pan so there’s less cleaning.
Above all, it protects the surface of the baking sheet from burning or rapidly heating up. Just make sure to cover the baking sheet entirely with food.
Also known as a Silent, this mat will protect your baking sheet unlike anything else. The biggest advantage it offers is protecting the sheet from the heat.
If you’re worried about reactivity, you can relax as silicone mats are food safe. In fact, you won’t even need cooking oil or nonstick spray.
Choose baking sheets that are made from durable metals, preferably aluminum. This way, they won’t warp or bend out of shape when heated in the oven.
Above all, avoid any methods that attempt to rapidly cool down or heat up the baking sheets. You’ll also regret it if your metal baking pans or sheets are too thin.
When you’re making an object you know is going to expand due to heat, you need to take steps to prevent warping and cracking. The extra space allows the concrete to expand, preventing stress cracks.
The problem is simple to solve because you’re dealing with a single flat surface. You can tell your metal cookie sheet is under stress when you hear it popping and crackling in the oven.
Thicker metal baking sheets and pans are often better able to withstand the stresses of heat expansion. In that case, with fewer surfaces needing room to expand, you can probably afford to choose a cookie sheet that’s a bit thinner.
A wobbly, warped pan is annoying, unsafe and won’t heat evenly since the bottom doesn’t sit flat on a cook top or oven rack. When a pan is heated or cooled rapidly, some parts expand or contract faster than others.
The best way to prevent pans from warping is to avoid exposure to rapid changes in temperature. In the following sections of this article, I dive deep into the six most common causes of warped pans and explain what you can do to prevent it from happening.
As I explained upfront, the molecular structure of pans is altered when they become exposed to rapid changes in temperature (energy), which causes uneven expansion and contraction. But, if you buy good quality pans and use them properly, you’ll never have to worry about warping.
Once you understand these causes, you’ll easily be able to avoid the mistakes that can ruin cookware. Rinsing pans with cold water while they’re still piping hot is the most common cause of warping.
Although it’s tempting to cool down and clean your pans immediately after cooking, do NOT rinse or soak them in cold water while they’re still hot. Doing so will result in Thermal Shock, which is when an object is exposed to a rapid change in temperature, causing it to expand or contract unevenly.
When the stress, or shock, is stronger than the material, it causes cracking, deformation, and warping. An everyday example of Thermal Shock is when you put an ice cube in a warm glass of water.
Cracking occurs because the outside layer of the ice cube warms up and expands much faster than its core. Warping due to Thermal Shock occurs so often that almost all cookware manufacturers explicitly warn customers not to expose a hot pan to cold water.
Clifton, one of the top U.S. cookware companies, has this warning in their use and care instructions: Allow pans to cool completely before washing. Never immerse a hot pan in cold water, as this will cause irreparable warping.
Cuisinart, another well-known cookware maker, provides similar advice in their use and care guide : Before you place the pan in water, allow it to cool. Cooking with extremely high temperatures is the number two most common cause of warped pans, and the science behind it is the same as (Thermal Shock).
A room temperature pan put on a burner set to high or an oven preheated to 450 degrees Fahrenheit or greater can expand too quickly in some areas while remaining unchanged in others. When this happens, the stress of the temperature change (Thermal Shock) causes the pan to expand unevenly and warp.
Good quality cookware is crafted to conduct and retain heat efficiently. For meals that require browning or searing on high heat, bring the meat to room temperature before placing it on the pan to minimize the difference in temperature between the pan and the meat.
This uneven expansion leads to the bottom of the pan either warping downward or upward. First, when exposed to rapid temperature changes, thick pans do a better job absorbing the expansion and contraction within its walls.
This means that thin pans often have hot and cold spots and are less likely to maintain the same temperature throughout. This problem relates to all types of cookware but is even more common with thin sheet pans.
Most home cooks have a few cheap and thin sheet pans for everyday baking and roasting. This isn’t usually a huge issue, but it becomes more problematic when baking cookies or other delicate foods.
Another way of determining the relative thickness of a pan is to compare the weight between several options with the same dimensions. Also, aluminum and copper conduct heat much faster but don’t retain it as well as steel.
In other words, aluminum and copper pans heat up and cool down very quickly. A quick response is helpful when you’re cooking meals that require precise temperature control, but it’s a recipe for warping if you’re not careful about avoiding Thermal Shock.
Although I didn’t conduct a perfectly clean scientific experiment, this anecdotal data supports the hypothesis that aluminum cookware is more likely to warp than stainless steel. All this means is that you need to be extra careful to avoid rapid temperature changes with aluminum cookware.
If you’re in the market for a new non-stick pan, I highly recommend choosing cookware made from hard-anodized aluminum. A nice improvement over regular aluminum, but a slightly higher percentage of complaints compared to stainless steel.
If you’re looking for new non-stick cookware, All-Clad and Clifton both make high-quality hard-anodized aluminum sets that are incredibly durable and warp -resistant. Certain stainless steel cookware collections are constructed with multiple layers of metals bonded together.
Steel doesn’t conduct heat as evenly as aluminum, so when you put a single-ply stainless steel pan without an aluminum core on the stove, the heat doesn’t spread evenly throughout the pan. If it’s a cheap pan and you can afford a new one, I’d chalk it up as a learning experience and make sure it never happens again.
Most manufacturers don’t cover warping since it’s almost always a result of misuse, but some do so it’s worth checking. This towel will serve as padding, so your pan doesn’t incur additional damage during this process.
If the cooking surface is warped downward (like a bowl), place the pan on the towel face down. Step 5: Place another towel over the upwards facing side of the pan to protect it.
Step 6: Gently tap the warped part of the pan with a hammer or mallet until it’s restored to its original shape. Step 4: Place the pan on the towel with the open side up when the cooking surface is warped upward or place the pan upside down if the cooking surface is warped downward.
Step 5: Instead of using a second towel, place a flat wooden block over the warped part of the pan. Cut the 2×4 down so that it fits within the walls of the pan and sits flat on the cooking surface.
Step 6: Forcefully hit the wooden block with a hammer or mallet until the pan falls back into shape. The wooden block spreads the force of the hammer evenly across the pan so that it flattens the entire surface.
Step 7: Adjust the block until the entire pan is back into its original shape. Additionally, thin, single-ply pans made with soft metals like aluminum and copper are more likely to warp than thick, multi-ply pans made with hard metals like steel and hard-anodized aluminum.
Both are available on Amazon and, to save you some time, I’ve linked to their most popular non-stick and stainless steel collections below. If the Towel or Wood Block methods don’t do the trick, keep in mind the six common causes of warped pans to avoid it from ever happening again.