An overview of induction cooktops, including maintenance and replacement tips. 

Induction Cooktops: An Overview

Induction cooktops are electrically-powered and create electromagnetic fields, which excite iron molecules in pans to generate heat. Here is a closer look at the types of induction units available today.

The widespread use of induction in North American cooking applications began about 20 years ago as foodservice operators began using single burner portable units as replacements for butane burners. While this mostly took place in display cooking applications, operators started finding other uses for induction.

Induction cooktops work by inducing eddy currents and hysteresis, which are the physical processes harnessed to generate heat directly in the fabric of the pan. When induction cooktops were first introduced, they had limited controls and were costly. Units now have advanced power level and temperature controls, are durable for true commercial environments and cost a fraction of the originals.

The technology spread to encompass a variety of units, including double burner, wok units and drop-in units, which have become standard in high-end kitchen island suites. In the last five years, induction has expanded into primary cooking applications in four and six burner commercial ranges and stock pot boilers. Most recently, it has successfully been applied to direct cooking surface applications, such as griddles and planchas.

Induction cooktops consist of two main categories: cooking and holding.

Induction cooktops come in countertop and drop-in versions in single and double hob models, which offer a front-to-back or side-by-side configuration. These come with the more familiar flattop cooking hotplates or in round bowl wok units. Foodservice operators can choose from a wide range of cooktops, which goes from 450-watt warming units to 10-kilowatt stockpot units. The variety of functions goes from low power warming to wok ranges to single-, double- and four-coil units. Operators can also choose griddle top models and hidden warmers to heat through the countertop.

Single hob induction ranges are typically about 13 to 15 inches wide, 15 to 17 inches deep, and 3½ to 5 inches tall. Double units may be roughly 27 to 30 inches deep. The hobs generally will hold a 14-inch-wide vessel, but these can be wider than the range itself. Typical stockpot capacities would be 24 to 40 quarts, but can be larger. High-powered induction ranges that must accommodate stock pots and braising pans will tend to grow in size with power level. For example, 60-quart stock pot applications will require higher wattage ranges.

Induction units' exterior construction goes from plastic or aluminum housings with tempered glass tops at the low end to heavy duty stainless steel housings with ceramic-glass composite tops on the high end.

Standard features include empty pan protection and over-heating limiters. Some manufacturers include self-analysis by the induction range to adjust to varying cookware, voltages and electrical cycles. Manufacturers may offer either control knobs or touchpad operation. Control panels that rely on cooking levels to select temperatures generally offer between 20 and 100 settings. The latest models have leveling feet to adjust to uneven tabletops.

Manufacturers continue to redesign induction to make them more affordable and provide operators with greater control and increased durability. Oftentimes, the innovations impact a unit's interior and remain invisible to the customer.

How to Know When to Replace an Induction Cooktop

An induction cooktop's service life varies greatly, depending on its components and usage. Here are three signs that it is time to replace an induction cooktop.

Ceases operation: A number of induction cooktops include self-diagnostic features that will provide visual prompts that can alert operators to such problems as an issue with the electrical supply, blocked grease filters or overheating. When an older or heavily-used induction cooktop is not operable, its service life has most likely ended and the foodservice operator should replace the unit.

Surface damage: If an induction cooktop's has a damaged or cracked surface, the operator should immediately disconnect the unit from its power source and replace it.

Cooking is compromised: It is time to replace an induction cooktop if the unit fails to maintain proper temperatures or can no longer read induction-ready pans.

Induction Cooktop Applications

Foodservice operators can use induction cooktops in place of traditional gas and electric ranges as well as burners. Here are a few ways operators from all industry segments are using induction cooktops.

Induction cooktops easily plug into almost any electrical outlet, and foodservice operators commonly use them in display cooking in catering and buffet applications. Induction cooktops are ideal for myriad of other applications, such as a sauté station, stock pot range, high-temp cooking unit, an auxiliary heating station for soup and sauce work, stir frying, warming salad components and in pastry kitchens. These units also are popular with single-plate demonstration cooking and plating.

When it comes to buffet lines, operators commonly use two types of induction units. One offers an effective controlled heat source for keeping food items at proper temperatures, while the other acts as a cooking unit for display action stations. Operators can also opt to use induction ranges that provide both heating and cooking modes.

Induction planchas and griddles add direct surface contact cooking. Foodservice operators often combine this method of cooking with sous vide equipment as a means of providing the sear either before or more often following cooking in the water bath.

Please note that very hot, greasy, high-humidity kitchens are not the proper environment for induction units. The electronics need to cool and will require ambient temperatures to be less than 105 degrees F. Also, foodservice operators need to separate grease-generating cookers with guards to avoid damaging induction electronics.

Maintaining an Induction Cooktop

For optimal results and food safety, foodservice operators should keep induction cooktops clean and free from food debris. Here are three other important maintenance tips that will help extend the service life of an induction cooktop.

Induction cooktops are basic pieces of equipment that are simple to maintain.
There are key factors to consider when taking care of these units.

• Induction cooktop surfaces are pretty durable and, due to the cooking method, spills aren't baked onto the unit. Avoid abrasive cleaners as they will scratch glass and ceramic tops.
• Allow tempered glass cooking surfaces to cool prior to wiping them clean with mild dishwashing detergent.
• Regularly clean the air intake and exhaust to ensure proper cooling of the unit's internal components.

Spec Check: Induction Cooktops

Induction cooktops can be a suitable replacement for traditional ranges and burners for those foodservice operations that don't have available gas. Here are five considerations foodservice operators should weigh when purchasing an induction cooktop.

Power: In terms of power, 1800 watts is ideal for light sauté and omelets; between 2200 and 3000 watts is appropriate for stir-fry, saucepots and higher volume cook stations.

Equipment: Operators should use only induction-ready pans with these cooktops, which will provide the most even heat and efficient cooking.

Application: Determined, in advance, in what capacity the induction range will function. Some units operate in dual modes, with the ability to hold food at serving temperature such as for a buffet, while others are more suitable as a cooking range for made-to-order applications.

Ventilation: While induction units create no effluent, vapors from the cooking may still require some form of ventilation, depending on local codes. Operators can comply with local codes by installing either vents, fans or both. Operators should allow at least 7 inches or more of unobstructed space under the induction range for venting.

Environment: If there will be grease and moisture in the air, units that have grease filters and conformal-coated electronics may be warranted.

Energy Efficiency and Induction Cooktops

Because no radiant heat is produced, induction cooktops do not affect atmospheric temperatures or raise air conditioning costs.

Induction continues to be among the most energy efficient heat sources available. For cooktops, induction typically posts an efficiency rating of 90 percent to 95 percent efficient, meaning that up to 95 percent of the energy consumed ends up in the pan. This compares favorably to electric hotplates, which typically perform at around 50 percent and gas at 35 percent.

The unit also saves energy because it stops producing heat once staff remove pans from the cooking surface.

Also with induction, since the pan completes the circuit, even if left on full power, when the pan is removed, power consumption drops to a fraction.

Because less heat is generated into the atmosphere, there is energy savings from a hood perspective, as well.

Sleep modes offer added energy efficiency. With this feature, if a pan is not returned to the unit in a specified amount of time, the cooling fan shuts down and the display changes. As a result, power consumption drops significantly.