Ever stepped foot in a kitchen? You likely already have a good grasp on which cookware pieces are best suited for certain jobs. While your kitchen might not be equipped with both a stock pot and a Dutch oven, it’s unlikely that you’d try to cook spaghetti in a sauté pan.
But what about knowing which cookware material is the best for a specific job or ingredients? Or, equally important, which materials can’t handle the ingredients on hand?
Before we dig into the details, let’s explored why different types of cookware materials are best suited for certain foods.
The Chemistry of Cooking: Two Reactions That Shape Your Cookware Choices
There are lots of reasons why we cook beyond killing bacteria to make it safe for consumption. Cooking can improve the texture of tough chunks of meat, change the color of your ingredients, help to improve their flavor and aroma or make cruciferous vegetables easier to digest.
Each of these reasons for cooking is the result of a chemical reaction between your ingredients and energy (in the form of heat).
But unless you’re grilling, your food isn’t coming in contact with an open flame. So, you depend on your cookware to transfer energy (heat) from your stovetop to the ingredients.
That might sound simple enough until you realize that the cookware material reacts with heat as well – and they each behave differently. The two factors that affect how well each cookware material can get the job done are thermal conductivity and reactivity.
Factor #1: Thermal Conductivity Affects How Quickly Your Cookware Heats Up
The thermal conductivity of a material is how readily it absorbs and transmits (releases) heat. In most cooking, you want your pots and pans to heat as quickly and evenly as possible, and to react quickly, should you turn the heat up or down.
The higher the thermal conductivity of a material the faster it will heat up. So, pots and pans with high thermal conductivity are generally more desirable.
Materials With Low Thermal Conductivity Also Create Hot Spots That Burn Food
It’s not just how fast your cookware heats, but how evenly. Thermal conductivity is important because heating elements—whether natural gas, electrical, or induction—don’t release heat all the way across the base of a pot or pan.
For example, stainless steel has low thermal conductivity as cooking materials go. If you placed a sheet of it on a burner, the area directly over the heating element or flame would get hot.
But, what about areas of the pan that aren’t in direct contact with the heating element? They heat up from conduction. And, because stainless steel is a poor conductor of heat, by the time the outer edges of the stainless steel were warm, the center would be extremely hot.
Materials With High Thermal Conductivity Heat Quickly and Evenly
Alternatively, a material with high thermal conductivity won’t just heat up in areas touched by your heating element, it’ll also quickly spread that heat to the entirety of the pan.
On the other end of the spectrum, there’s copper. This material offers high thermal conductivity. And, cookware made of copper is coveted for making delicate candies because heat spreads so quickly and evenly throughout a pot or pan.
In a nutshell, materials that have low thermal conductivity will heat slowly, create hot spots and can burn delicate ingredients. Materials that have high thermal conductivity will heat quickly and evenly.
From high to low, here’s how five popular cooking materials compare when conducting heat:
|Cast Iron||80 W/(m·K)|
|Carbon Steel||51 W/(m·K)|
|Stainless Steel||16 W/(m·K)|
How do you apply your understanding of thermal conductivity when choosing the right pots and pans for the job? While you can certainly reference our list at the end of this article to match different cookware materials with common ingredients, it helps to understand why certain materials are a no-go when cooking different meals.
The Do’s and Don’ts of Stainless Steel Cookware
Let’s assume you have a thin stainless steel pan or skillet. We know that stainless steel is a poor conductor of heat, so you’ll want to avoid cooking delicate ingredients such as:
Pancakes - Liquid pancake batter is prone to seeping across a pan, allowing it to cook unevenly in stainless steel. This will lead to some areas being burnt while others are undercooked.
Chocolate or candy - Despite constant stirring, these temperamental liquids are prone to scorching and require an even application of heat throughout.
Sauté - Flash frying foods requires cookware that is sensitive to temperature changes.
Unfortunately, stainless steel by itself is such a poor conductor of heat that it makes a miserable cookware material by itself.
If you have cookware that’s made from stainless steel alone, it’s best used for ingredients that will be constantly moving around the pan. This includes:
Boiling water or heating broth-based soups. The movement of liquid ingredients helps to evenly distribute heat so that no area burns. If your soup contains heavy chunks of meat or vegetables, be sure to stir frequently.
Stir-fried vegetables. Items that are constantly stirred while being cooked at high heat, such as stir-fried vegetables or breakfast potatoes can benefit from high temps at the center of the pan, then being moved to the cooler edge while other items sear.
Bottom Line Regarding Thermal Conductivity and Cookware Materials
Don’t use stainless steel or carbon steel cookware for delicate ingredients unless clad with another metal.
Even moderately conducive cookware, such as cast iron, should be avoided when immediate heat is required. Although, cast iron is thick enough to retain a heated charge, and will give you a lasting cooking surface for browning. (More on this material shortly.)
Factor #2. Reactivity – When Cookware Changes the Taste of Your Food
After reading the section above, you might be wondering why isn’t all cookware made of copper or aluminum? Sadly, thermal conductivity comes at a price – cookware materials that heat quickly and evenly are reactive.
A reactive pan contains metals that might interact with certain foods. Aluminum and unlined copper are all examples of reactive metals. (Note that cast iron gets its own special section shortly.)
The good news is that not all types of foods react similarly. Here are the do’s and don’ts of cooking with reactive materials.
The Do’s and Don’ts of Cooking With Copper and Aluminum
Avoid cooking the following in your reactive cookware:
Acidic foods - Tomato sauce, anything with lemon or citrus, even fruits and hams will take on the flavor of your metal cookware and should be heated in a non-reactive pot instead.
Light colored foods - Items like eggs will take on a dark color or develop gray streaks.
However, because cookware made of these materials conducts heat very well, copper and aluminum are ideal for cooking rice, melting sugar, and pan-browning meat. The consistent heat and fast reaction time of reactive materials allow you to control what’s happening inside your pot or pan.
Is Copper Safe to Cook With?
Foods will also pick up chemical elements from reactive cookware, causing us to ingest metals like copper and iron. Our bodies process iron relatively easily, so using cast iron cookware regularly isn’t a problem. However, we have a harder time eliminating copper.
Basically, when copper cookware is used to occasionally whip egg whites or sautéed vegetables, the small amount we ingest isn't enough to harm us, but you definitely don’t want to use copper for everyday use.
Bottom Line Regarding Reactivity and Cookware
Reactive metals are great for cooking items that require a responsive material. But, avoid cookware made from copper or aluminum when cooking anything with a pH of 4.6 or below (the lower the pH, the higher the acid content). Additionally, save your copper for special occasions.
The Exception: Cladding Helps Poorly Conducting Materials Heat Faster and More Evenly
In Finding the Perfect Pots & Pans for Your Cooking Style we share how manufacturers have been able to mitigate the poor thermal response of materials like stainless and carbon steel by combining different layers of metals to make what’s called clad cookware.
The cladding means that different materials have been bonded under high pressure to make a sandwich with high conductivity “filling” that’s encased in stainless steel.
There are several variations on this theme: steel- or tin-lined copper, stainless steel with aluminum or copper disk, stainless steel-cladded aluminum, and stainless steel-cladded copper.
The table below summarizes the effectiveness of various cladding material combinations from most effective to least:
|1||Copper with tin lining||Highest response; tin lining can be finicky and can be susceptible to melting; copper exterior requires more care|
|2||Copper with stainless steel lining||Copper exterior requires more care but imparts the utensil with copper’s excellent thermal properties|
|3||Aluminum with stainless steel lining||Thick aluminum provides excellent thermal response to thin steel interior|
|4||Copper fully clad by stainless steel||Copper layer may be thinner than copper with stainless steel lining; exterior and interior are durable and easy to maintain|
|4||Aluminum fully clad by stainless steel||Aluminum layer may be thinner than aluminum with stainless steel lining; exterior and interior are durable and easy to maintain|
|4||Aluminum with stainless steel lining and copper exterior||Same performance as cladded aluminum, but with the difficulties in maintaining copper|
|5||Stainless steel with copper disk||Curved edge of the bottom causes the disk to not come into full contact with the complete bottom of the pan resulting in inferior heat conduction as compared to cladded copper|
|5||Stainless steel with aluminum disk||Same as stainless steel with copper disk|
The Do’s and Don’ts of Cooking With Cast Iron Cookware
You might have noticed that cast iron is both moderately thermally conductive and, conversely, moderately reactive. Based on those factors alone, you might think that cooking with cast iron offers the worst of both worlds.
But, because iron is so cheap, cast iron pans are made to be incredibly thick. Their heft means that, while cast iron takes some time to charge (heat-up), they maintain consistent heat for a long time.
What about reactivity?
Seasoning your cast iron—a process by which layers of fat are slowly cooked into the porous iron until the fat polymerizes forming a protective barrier—creates a non-stick surface that reduces a cast iron’s reactivity. (Though seasoning doesn’t eliminate it completely.)
This makes cast iron pans cookware great for cooking lots of things. But the trick to great results is knowing when to use them and when another pan might be better for the job at hand. Here are five things not to cook in a cast-iron skillet:
- Tomato sauces
- Deglazing with an acidic liquid, such as wine or vinegar
- Delicate fish
On the upside, cast iron's ability to get and stay really hot makes them ideal for searing meats and cooking stir-fries. Additionally, they can go straight from stovetop to oven, which makes them perfect for baked goods like cornbread.
See Also: Guide to Cast Iron Cookware
The Do’s and Don’ts of Cooking With Non-Stick
Non-stick pots and pans are generally made of aluminum. However, it’s less the cookware’s material that we’re concerned with, and more that interior non-stick coating.
We’ve covered the properties, chemical composition, and safety concerns surrounding non-stick in a three-part series Non-Stick Cookware 101.
But, here’s what you need to know in a nutshell: Various non-stick coatings can withstand different temperatures ranging from 350-degrees to 500-degrees. Once the coating is heated beyond their temperature limit, it may begin to “off gas,’ which can cause flu-like symptoms in humans and be fatal to pet birds.
Because to need to reach at least 500-degrees to brown meat and 600-degrees to achieve a good sear, non-stick cookware isn’t a good choice for those ingredients.
The Right Cookware Material for Your Favorite Foods
There is really no single cookware material that is perfect for all foods, so it's a good idea to buy different pieces to suit different needs on hand.
Here are the best cookware options for your favorite foods:
Steak: Cast iron is the best material to help you achieve a sear. However, aluminum or stainless steel clad cookware will also work well. Don’t use non-stick coated cookware.
Tomato sauce: Stainless steel clad with an aluminum or copper disc will keep tomato sauce true-to-taste without creating hot spots. Avoid copper or cast-iron.
Braised meats: Since deglazing requires an acidic liquid, braised meats follow the same rules as tomato sauce.
Baked goods: If you like a good, crisp edge to your cakes and brownies, cast iron provides a surprisingly great alternative to coated baking sheets. However, this material takes on the taste of ingredients, so considering having a separate cast iron for sweets.
Eggs: Since eggs don’t require high heat, non-stick cookware is best to provide an even, slippery surface that yields perfect omelets. Stay away from cast iron for reasons of discoloration.
Hard-boiled eggs: A stainless steel sauce pot gets the job done.
Fish: Like eggs, very flaky fish fillets can stick to a pan, making non-stick surfaces your best option. Avoid cast irons, lest they take on a lasting fishy flavor and require deep cleaning before cooking other ingredients.
Sautéing veggies: A stainless steel skillet can handle any temperature range without imparting any unwanted tastes.
Whipped egg whites: This is one place where copper cookware shines. A safe chemical interaction occurs between copper and egg whites that stabilizes whipped egg whites against overbeating or “unfolding.”
A Pot and Pan for Every Job In the Kitchen
Whether you’re building your first kitchen’s arsenal of tools or just decluttering and purging your outdated and old equipment, it can be tough to know which pots and pans you really need and which are just taking up precious cupboard space.
Love steak? Stick with cast irons. Enjoy a good omelet? Be sure to have a non-stick pan on hand. Want to make candied treats? Copper is your go-to cookware material.
Now, with a solid grasp on the relationship between different types fo cookware materials and your favorite ingredients, you can tailor your stock of pots and pans for the foods you love to cook.