Microwaves are typically one of the most underspecified pieces of equipment in commercial kitchens due to the stigma of being considered a tool for reheating, but they have become a staple in cafes because of their small size and versatility. Commercial microwaves complete the same tasks as several pieces of equipment, such as steaming, rethermalizing and defrosting, while utilizing less energy and space.

Depending on the application and menu, culinary staff can use microwave ovens to reheat or rethermalize foods that were previously cooked as part of a cook-chill system, boost the temperature of foods from holding cabinets, such as burgers, or cook fresh foods. The only limitation of a microwave is the inability to brown foods. The exception is high-speed combination ovens, which utilize convection and infrared radiant elements to quickly brown and heat foods.

Foodservice operators can choose from a wide range of microwave sizes. Cabinet sizes on most commercial models range from 13 to 25 inches wide, 13 to 25 inches deep and 13 to 19 inches high. Usable cavity space generally ranges from .8 to 1.56 cubic feet. Larger-size cavities can hold a 13-inch platter or two 4-inch-tall full-size steam table pans with covers.

It’s important to note the cubic food cooking capacity has a direct correlation to the oven’s chassis size and wattage. For example, a larger unit may have a 1.6-cubic-foot capacity cavity and accommodate full-size hotel pans, operating at 3500 watts.

Higher wattage equals faster cooking. For instance, a food item that cooks in a 1000-watt microwave oven at 4 minutes and 3 seconds will cook in a 2200-watt oven in only 1 minute and 50 seconds.

Microwave classifications include light duty, heavy duty and specialty. Light-duty types are typically between 1000 and 1200 watts and not as popular in cafe settings. Heavy-duty models that require more than 1200 watts are better suited for these operations.

In terms of construction, commercial microwaves feature a stainless-steel cabinet and cavity, although economical models may have a painted cavity instead. Adjustable legs are commonly chrome-plated, and powder-coated handles are a popular feature. Heavy-duty hinges are designed to withstand the wear and tear of repetitive door slamming.

As for the design, heating components are housed in the cabinet, and controls are either on a side and/or top escutcheon, depending on the complexity of programming required. Operators can choose from units that have dial or one-touch operation. Most commercial microwaves are programmable.

One standard microwave feature is stage cooking, or the ability to control how much of the oven’s energy permeates the food during different stages of a cook cycle. For example, a unit can defrost, cook and hold a food item with one cook cycle. The operator only has to press one keypad rather than monitor the food or constantly change the power level.

Variable power levels of microwave energy measure between 0 percent and 100 percent and are usually selected in 10 percent increments. Other commercial unit components include LED or VFD displays and a filter with a clean filter reminder to protect oven components in harsh commercial kitchen environments.

Sensors that automatically adjust power output and cooking based on how much power is being inputted are typically standard. For example, some outlets may input 208 volts, while others are 240 volts. The automatic voltage sensor will determine voltage input and adjust the microwave’s operation accordingly.

Most options for microwaves relate to programming preferences, such as end-of-cycle signals or how the operator is notified that a cook cycle is done. This consists of a beeping sound. Cafe operators who prefer to manually enter cook times or use only preprogrammed keypads should confirm that an oven’s cook cycles can be interrupted to input additional programming information.

Microwave ovens generally come equipped with an automatic shut-off device to prevent overheating. Doors are required to have two independent but interlocking systems that automatically shut off oven operations when a door is ajar. Doors also come with seals and absorbers to eliminate the chance of radiation leakage. Other features that some makers offer include Braille keypads, self-diagnostic capabilities, multistage cooking, bottom energy feed and drop-down counter-style doors.

USB programming is not readily available on most commercial microwaves, but models are available that can save programs to a flash drive. However, this is more commonly seen on high-speed combination ovens.

Along with high-speed combination ovens, or microwave-assisted cooking — which combine microwave energy with traditional cooking energies like convection and infrared heat — there are also specialty microwaves that accommodate hotel pans and can act as steamers.

Purchasing Considerations

Microwave ovens’ magnetron tubes are rated for between 3,300 and 3,800 hours of use. Typically, when these units’ three-year warranties expire, the tubes are at the end of their service life.

Before choosing what size microwave an operation requires, determine the cooking vessel size. Cafe operators should also consider how they intend to use their microwave ovens and what wattage is necessary. For example, if the intended application is bulk defrosting, then operators should consider a higher wattage. If a menu warrants a microwave that can store cooking programs, a model offering stage cooking or a multiple quantity option may be necessary.

Foodservice operators need to determine how many times staff will use the microwave each day, the necessary space requirements and the unit’s electrical needs.

Microwave ovens can work in high-volume cafes as well as smaller operations. These ovens can free up stations that may get overloaded by providing a quick-heat solution either with fully heating or starting the heating process. Because microwave heat works from the inside of the product outward, this is especially helpful with dense products that would normally take 15 to 25 minutes in an oven and often burn on the outside before the center is sufficiently heated.

It often pays to purchase microwaves with the most power, given the need for quick service at today’s cafes. These units can take the place of other pieces of equipment. For example, soup can be heated to order in microwaves, thus preventing small operators from having to purchase soup warmers. Microwave heating can prevent operations from dealing with waste and potential food safety issues that can occur when a product is put through more than one heating cycle.

Microwave Care and Maintenance

Although microwaves are one of the most low-maintenance pieces of equipment in commercial kitchens, operators can take certain steps to prolong these ovens’ service life.

Microwave ovens require cool air to keep them from overheating and to ensure the units function properly. For this reason, location represents a key factor in keeping these ovens operating at peak performance. Placing a microwave above a fryer or steamer could impact performance and longevity.

Keeping microwaves clean is also important. Wipe down the unit throughout the day. Keep air vents clear of both dust and debris by vacuuming this area, wiping down louvers and cleaning out cooling fans. This will help the units operate properly.

Adhere to a maintenance program to to ensure microwave doors do not leak radiation. Service techs use tools to gauge this, but operators can perform their own test by shutting the door on a dollar bill, which should not be easily pulled out.

Operators need to make sure the microwave’s panels and lights aren’t cracked, which could cause problems if moisture from food reaches the oven’s interior. Never turn on a microwave when empty since the unit needs to emit energy through product absorption.

The service life for commercial microwaves varies, depending on use. When used often, these ovens typically have an average service life of between 5 and 7 years, compared with 10 years or more for microwaves that are used less often.

Due to the low cost of replacement, only about half of commercial microwaves get repaired. These mainly include heavy-duty types and combination microwave/convection ovens. Service calls range from faulty magnetrons or bad computer boards, which are big-ticket items and not worth the cost to fix.