Metallic Pots And Pans: What's The Metal?

Pots and pans are often made from metals such as copper, aluminium, and iron. These metals are suitable for cookware because they have high thermal and electrical conductivity, malleability, and ductility, which are properties imparted by metallic bonding.

The two most common metals used in commercial cookware are aluminium and stainless steel. Aluminium is popular because it is an excellent conductor of heat, inexpensive, and lightweight. However, it is porous and reactive, potentially transferring flavours from previously cooked foods and leeching into acidic foods. Stainless steel, on the other hand, is non-porous, non-reactive, durable, and scratch-resistant. It is widely considered the best material for cooking, especially with acidic foods. However, it is a poor conductor of heat and can be more expensive.

Stainless steel is the safest metal for pots and pans

Stainless steel is a safe option for pots and pans. It is a metal alloy that typically contains iron, chrome, and nickel, and sometimes other metals. It is called "stainless" because it is resistant to rust and corrosion, which makes it a great material for cooking. Stainless steel is also non-porous, so it won't transfer flavours from one dish to another. It is also non-reactive, meaning it is safe to cook acidic foods in it. Stainless steel is harder and more durable than other metals, so it is more resistant to wear, scratches, and tarnishing. Most stainless-steel cookware is also induction-ready.

While stainless steel is a safe option, there are some cons to consider. Stainless steel is not the best conductor of heat, so it distributes heat more slowly and less evenly than other metals, like aluminium. This means food may not cook as evenly. Stainless steel is also more expensive than other metals. Additionally, if you have a sensitivity or allergy to nickel, you may find that stainless steel aggravates your allergy.

When choosing stainless steel, it is important to buy high-quality products. Look for food-grade versions and avoid scratching the surface to minimise the risk of any toxins leaching into food.

Metals like copper, aluminium and iron are suitable for cookware

Metals like copper, aluminium, and iron are suitable for making cookware due to their properties, which are imparted by metallic bonding. These properties include high thermal and electrical conductivity, malleability, and ductility.

Cookware, such as pots and pans, often uses these metals because of their suitability for cooking applications. Copper, for instance, is known for its excellent heat conductivity, allowing it to distribute heat evenly. This makes it a favourite among professional chefs worldwide. However, copper is highly reactive to acidic foods and requires polishing to maintain its shine, making it a costly option.

Aluminium, the second-best heat conductor after copper, is lightweight and inexpensive. It heats up quickly and evenly distributes heat, making it a popular choice for restaurants. However, it is porous and reactive to acidic foods, which can result in a metallic taste in dishes.

Iron, another suitable metal for cookware, is extremely durable and can last a lifetime with proper care. It retains and evenly distributes heat, making it a preferred material for items like frying pans and grill pans. However, cast iron is slow to heat up and cool down, and it can be reactive under certain conditions, requiring extra care for maintenance.

In summary, while copper, aluminium, and iron all have their advantages and disadvantages, they are suitable for cookware due to their heat conductivity, durability, and ability to distribute heat evenly.

Aluminium is the second-best heat conductor for pots and pans

Aluminium has a high thermal conductivity of 205 W/(m/K), which explains why it heats up quickly and cooks food evenly. It takes less time to heat up to your desired temperature and distributes heat more evenly than stainless steel. This more even heat distribution means more evenly cooked food, making aluminium cookware the most popular choice among restaurants.

However, aluminium is a reactive metal, and if used to cook highly acidic or alkaline foods, the food will likely take on a metallic and bitter flavour. This is because aluminium is porous, and can potentially transfer flavours from foods previously cooked in the pan. When cooking with foods that are high in acidity, reactive metals like aluminium can leech out into the food, leaving behind a metallic flavour. This could be a health concern for those with weaker immune systems, such as young children or the elderly.

To prevent this, aluminium cookware is always coated to provide a barrier between the metal and the food. Most aluminium cookware incorporates a non-stick coating that will protect food from reacting with the metal. Manufacturers have also developed a process known as anodization, which treats the aluminium while retaining the metal's high thermal conductivity. This process involves a series of electrochemical baths that thicken the oxide film that forms naturally on aluminium. As this coating hardens, the metal becomes more scratch-resistant and will no longer react with acidic or alkaline foods.

Cast iron is a poor conductor of heat

The thermal conductivity of cast iron is 52 Watts per meter-Kelvin (W/m K), compared to 54 W/m K for carbon steel, 237 W/m K for aluminum, and 413 W/m K for copper. Therefore, cast iron is approximately 4.5 times worse at conducting heat than aluminum, the most common choice of metal for non-stick cookware, and 8 times worse than copper, which is often used by high-end cookware manufacturers.

The poor heat conductivity of cast iron is due to its low heat conductivity, which means that heat is transferred slowly from the bottom surface of the pan to the other parts. As a result, cast iron cookware is less responsive to adjustments in temperature and takes longer to release accumulated heat. This is why cast iron is not suitable for sautéing, where quick temperature changes are often required.

Despite being a poor conductor of heat, cast iron is valued for its remarkable ability to hold a uniform temperature. Once heated, cast iron cookware will remain at a uniformly high temperature for even cooking. This is ideal for dishes such as fried chicken and cornbread.

In summary, while cast iron may be slower to heat up than other metals, its ability to retain heat and distribute it evenly makes it a popular choice for various cooking methods and dishes.

Stainless steel is made by adding chromium and nickel to steel

Stainless steel is a metal alloy created by adding chromium and nickel to steel. It is also known as inox, corrosion-resistant steel (CRES), or rustless steel. The addition of chromium, usually between 10 and 30 percent, gives stainless steel its remarkable resistance to corrosion and heat. Nickel is added to stainless steel in smaller amounts, typically ranging from 8 to 12 percent, to further enhance its corrosion resistance. The combination of these elements results in a durable and non-porous material that is widely used in cookware, cutlery, and appliances.

The process of making stainless steel involves melting the base metals in electric-arc or basic oxygen furnaces. This is followed by refining to lower the carbon content, which can be achieved through the argon-oxygen decarburization process. By adjusting the ratio of oxygen and argon, carbon can be removed while preserving valuable chromium, allowing for the use of cheaper raw materials.

Stainless steel is known for its corrosion resistance due to the presence of a chromium oxide layer that forms a protective barrier. This layer also contributes to its non-reactivity, making it safe for cooking with acidic foods. Additionally, stainless steel is harder and more durable than other metals like aluminum, making it more resistant to wear, scratches, and tarnishing. However, one disadvantage is its lower thermal conductivity compared to aluminum, resulting in slower and less even heat distribution.

Stainless steel cookware is commonly found in commercial kitchens due to its advantages over other materials. It is non-porous, non-reactive, durable, and easy to care for. While it may be more expensive, stainless steel offers superior corrosion resistance and can be induction-ready, making it a popular choice for those seeking long-lasting and low-maintenance cookware.

In summary, stainless steel is a versatile and durable material created by adding chromium and nickel to steel. Its unique properties, such as corrosion and heat resistance, non-reactivity, and durability, make it a preferred choice for cookware and various other applications.

Frequently asked questions