Part 1 of this series explained how Induction cooktops use a magnetic field to directly heat the the pot or pan. Part 2 explained the growing popularity of induction cooking by exploring induction’s many advantages over conventional cooking technologies. This installment of the Induction Cooking Explained series expands on an issue introduced in part 3 by looking at the types of cookware that work best on induction cooktops and explaining which types of cookware should be avoided.
Unlike gas and conventional electric cooking elements, induction elements do not heat up and then transfer heat to the pot or pan. Instead, they directly heat the pot or pan via magnetic hysteresis loss. While the home cook or restaurant chef has no need to understand the details of magnetic hysteresis, he or she must be aware that induction cooking only works with pans made of a ferrous (magnetic) material and will not work with aluminum, glass or ceramic cookware. In addition, although steel is normally magnetic, some stainless steels are actually non-magnetic alloys unsuitable for induction cooking.
Because of induction’s growing popularity, many manufacturers whose cookware is compatible with induction cooking will state this in their product descriptions. In addition you can perform an easy test: generally speaking, if a magnet sticks to the bottom of a pot or pan then that pot or pan can be used for induction cooking. Conversely, if a magnet does not stick to the bottom of the pan, then the pan cannot be used for induction cooking.
In addition to being magnetic, a pot or pan used for induction cooking must have a flat bottom; therefore traditional round-bottomed woks are not suitable for induction cooking, nor are pots or pans that have extremely warped bottoms. Several manufacturers make Chinese-style induction cooktops specifically designed for round-bottomed woks; however these cooktops are suitable only for woks and can’t be used with flat bottomed pans.
The materials suitable for induction cooking fortunately turn out to be among the most commonly used and effective cookware materials: cast iron, carbon steel and some stainless steel. The first of these types, cast iron, is a very traditional type of cookware and is well suited for a wide range of applications. Cast iron has a high heat capacity compared to many other cookware materials, so cast iron pots and pans tend to be relatively slow to heat up and, once heated, tend to hold heat longer once the heat source is removed. This property is advantageous for many types of cooking (for example, non-enameled cast iron skillets excel at browning and searing meat because of this property), but cast iron cookware is not ideally suited for dishes that require rapid temperature changes. Also, cast iron cookware must be seasoned to protect against rust, to prevent acidic food from reacting with the cookware, and to prevent food from sticking (a well seasoned cast iron pan is almost as stick resistant as a modern “non-stick” pan) and care must be taken when cleaning cast iron cookware not to remove the seasoning. cookware
Enameled Cast Iron
In addition to the plain cast iron cookware discussed above, several manufacturers produce enameled cast iron cookware. The enamel coating means that the cookware:
- does not have to be seasoned
- is fairly easy to clean
- will not react with acidic foods.
Furthermore, enameled cookware is attractive because the enamel coating is typically available in a variety of bright colors. However, enameled cookware does not do a good job of browning food and the enamel is subject to damage if the cookware is dropped or heated to an extreme temperature. Both enameled and plain cast iron work well with induction cooktops.
Carbon steel is common in woks used for Asian-style stir-fry cooking but is otherwise not commonly used for cookware in the U.S. Like cast iron, carbon steel must be seasoned to reduce sticking, rusting and to prevent food from reacting with the cookware. Also like cast iron, once properly seasoned, carbon steel is almost as stick-resistant as modern non-stick cookware. Flat bottomed carbon steel cookware works well with induction cooktops; however round-bottomed woks will work only with specially designed Chinese style induction cookers.