Steam cooking works by using heat energy to convert liquid water to gas. This heat energy is measured in British Thermal Units (BTUs) which represent the amount of heat required to raise the temperature of one pound of water up one-degree Fahrenheit. It takes 180 BTUs to raise a pound of water from 32°F to its boiling point at 212°F. This is where the water begins the process of absorbing heat, known as latent heat of vaporization. However, it takes 970 BTUs for that pound of water to evaporate into steam. Therefore, the higher BTU output on your commercial steamer, the faster it converts. Steam carries up to six times the heat energy of boiling water.

Commercial food steamers channel this energy to fully cook and prepare products for consumption. There are many operational and health benefits to cooking with steam, including the efficiency of heat transfer that quickly cooks products without drying them out. Steam also helps to lock in nutrients normally lost in other methods of cooking. As a result, steamed vegetables retain their texture and color, as well as their natural life enhancing vitamins. Another health benefit commercial steamers offer is eliminating the incorporation of fatty cooking oils necessary with other methods.

Before making the final decision on which commercial steamer is right for your operation, read on to learn more about different steam sources, types of steamers, and other considerations that can assist along your buyer’s journey.

Our top commercial steamer brands include:

Cleveland – with a long history of designing innovative equipment, featuring convection, countertop and pressure steamers.

Vulcan – from compact to high efficiency, Vulcan steamers are available in gas or electric, easily outfitted to accommodate any commercial space to offer tasty and nutritious items.

Groen – featuring carefully crafted and industrial grade products to simplify and streamline kitchen operations of any size.

Southbend – notable for their constant innovations in energy savings, cooking speeds, automation and safety.


Steam Sources

Steam is produced in a variety of ways. The first step in selecting your steamer is understanding how it converts water to steam.

Direct Steam

Direct steam steamers are designed to generate clean steam without cross contamination from a central steam supply, hooking up to your building’s existing supply. The steam must be considered “food safe,” containing no contaminants or chemical impurities. If your building already has a ready steam supply, direct steam steamers are your most cost-effective choice; however, they are not a good option if your building isn’t outfitted with a steam supply or generator.


Steam Generator

Some steamers produce their steam via an internal generator. Designs vary. Some steamers with built-in steam generators incorporate steam jets, while others spray water onto the heating components. There are a few benefits to selecting a steamer with a steam generator. They are easy to clean and maintain, and they aren’t as susceptible to limescale buildup as boiler-based steamers are. However, they also don’t produce the same high level of output that boiler steamers produce, and recovery time is slower.



Steamers that produce their steam with the use of a boiler either have the boiler built into the cabinet, or the units may rest on top of a boiler base. Boilers vary, some operated with gas, others electric, and some use a steam coil. They are designed to operate more than one piece of equipment, but pay attention to the boiler capacity which will either be rated in horsepower or pounds of steam per hour. The capacity must be matched to the demands of the steamer.

Boiler operated steamers are ideal for high volume operations, steaming large batches of food with fast recovery times. To maintain a high rate of performance, they require regular maintenance and deliming.

Steam generators and boilers are sometimes referred to interchangeably. However, there are key differences. Boilers are closed vessels that create steam under pressure and are tightly regulated, held to the American Society of Mechanical Engineers standards, pressure tested at the manufacturing plant, and National Board Registered. True boilers include a valve controlling and restricting the steam, a pressure gauge, water sight glass, pop-safety or pressure relief valve, and other built-in safeguards. Steam generators are open systems that do not build pressure and are much less regulated.


Steam Generator

Boilerless steamers either spray water onto a heated plate or heat water in a compartment to produce steam, making them ideal for low-volume operations. The cook times are longer, but they typically have much lower utility and maintenance costs than the previous steamer types.

Along the same lines as boilerless steamers, connectionless models can be filled manually. These are a great option if your operation doesn’t have a water or drain connection readily accessible.


Types of Steamers

Now that we understand a bit more about how steamers produce their steam to deliver desirable results, it’s time to delve deeper into the individual types of steamers you’re likely to come across on the market.

Pressure Steamers

With pressure steamers, the steam gradually builds within the compartment during the cooking process, allowing food to cook at temperatures up to 250°F. The pressurization of the cooking compartment can range between 5 and 15 PSI. Because the pressurization can build to intense heights, there is a risk of damaging or overcooking delicate products, as well as flavor transference between dissimilar items.

Pressure steamers are ideal for high volume batch steaming and are sometimes referred to as “lazy steam” because they cook food from the outside in. This is a great way to cook fresh, defrosted or loosely packed frozen products quickly; however, it’s best to avoid cooking frozen block products because the outside will become overcooked before the inside even thaws.

High pressure and low pressure steamers are available. Low pressure cookers operate at around 5 or 6 PSI and are ideal when cooking single items in large volume. They are popular in schools, institutions, large cafeterias, etc., and come equipped with gas or electric boilers built into the cabinet base. Some are also available with direct steam hookups, or with a steam coil heat exchanger.

High pressure steamers can build steam up to 15 PSI. Though they are capable of a higher output and faster cooing times, high pressure steamers are still not recommended for delicate foods or frozen block products.

In addition to high and low pressure steamers, there are also countertop and floor steamers and countertop models. Countertop steamers are available in gas, electric, or direct steam operation requiring no water or drain connection. They are manually filled with water and then drained through a petcock, which is then easily drained into a pitcher. Floor steamers are available for direct steam or outfitted for a boiler.


Convection Steamers

Also known as pressureless steamers, commercial convection steamers were introduced in the 1970s as an alternative to pressure steamers. These steamers feature vented steam compartments that relieve the pressure. Instead of relying on the pressure to cook food thoroughly, the heat is transferred through forced convection air achieved via a blower, port or distribution manifold that focuses and accelerates the steam produced with a boiler or generator.

The venting system eliminates the air from the cooking compartment, allowing the steam to expand and fill, cooking fast and gently at a lower temperature. Convection steamers are one of the most popular choices because they generally come at a lower price point than pressure steamers; produce higher quality results; are more versatile because they can also poach, stew, reheat, and thaw in addition to steam; are easier to operate and more forgiving that their counterparts. The risk of flavor transfer is also eliminated due to continuous ventilation. The drawback is they are not as fast.

It is recommended to use perforated hotel pans to prepare most food items, but some foods like pasta, rice, scrambled eggs, and casserole dishes are prepared in solid pans.

Some brands manufacture models that can operate in either pressurized or pressureless steam modes. This provides operators with more flexibility and enhances water and energy conservation efforts. These steamers are often found in schools, universities, hospitals, correctional facilities, banquets, and large cafeterias.


Microwave Steamers

Several brands have designed high powered microwave ovens specifically for steaming. Microwave steamers save space compared to other countertop pressure or convection steamers yet feature a large internal cavity to accommodate different food pans, great for quickly and conveniently preparing vegetables or other items. They are cost effective and don’t require a water supply or drain, and most don’t need placed under a hood for ventilation.

Flash Steamers

Sometimes referred to as tortilla steamers because they’re often used for quickly warming tortillas or bread, flash steamers are ideal for rejuvenating stale foods, cooked meats, or quickly preparing small portions of frozen vegetables. They are compact units that fit nicely on countertops, making them great for kitchens with limited space. Commercial flash steamers are operated by filling with a pint or two of water that is then heated on a plate, converted into steam and administered like a quick shot to revitalize foods. They are likely to be seen in small diners, delis, bars and snack shops.

Other Considerations

A filtered water supply and ENERGY STAR® certifications are a couple other considerations worth researching prior to purchase.

Using filtered water greatly improves taste, enhancing product quality. Filtered water also slows mineral deposit build-up in water lines. This reduces the build-up of scale on heating units, water probes and the cooking chamber, thus enhancing the operational efficiency and longevity of your steamer.

ENERGY STAR® rated products are given this designation for designs that reduce energy usage, thereby contributing to a cleaner environment. Products with an ENERGY STAR® label reduce utility bills and, in some states, qualify for sizeable rebates. ENERGY STAR® qualified steamers feature sealed cooking cavities that don’t consume nearly as much energy and water as traditional open systems. The average Energy Star commercial steamer is 60% more energy efficient than standard models. For more information on ENERGY STAR® rebates, click here.

Water hoses for connection to a water supply and accessories like casters, assemblies, steamer baskets, and more are also available to help you get the most out of your commercial steamer.