Foodservice operators can choose from a variety of fryer types and styles, from models geared for general use to multi-purpose and specialty units. Donut fryers offer a shallow cooking depth, while deep vat units can cook items like fries and chicken. Flat bottom fryers can accommodate floating products, like fish and seafood, while operators commonly use larger conveyor units for production line frying as in a doughnut shop. Operators can place their fryers in a battery configuration, where five or six fryers sit side by side, and employ a single, central filtration system.

Operators can choose from gas, electric, infrared and induction-heated fryers. Countertop and floor models are available, too. Fryer wells come in a variety of widths, from 11 to 34 inches and depths of up to 34 inches. Manufacturers generally measure tank capacities by pounds or the maximum oil volume. Operations with limited footprints and low-volume frying needs can utilize ventless countertop fryers, which offer 2- and 3-pound capacities.

High-volume operations typically utilize pressure fryers, which cook food with a combination of hot oil and steam. Cooking under pressure raises the boiling temperature of the product’s juices without boiling it. This can result in a juicier product that’s less greasy when compared to other frying methods. Also, because there is no flavor transfer between foods, these units can simultaneously prepare a variety of items, like fish and fries.

Operators can choose from three basic fryer configurations. Open pot designs with heating elements on the tanks’ exterior, a popular choice for preparing fries, provide more frying space and easier cleaning. Tube type units carry gas through pipes located inside the pot, which serve as the heat source. Shallow square flat bottom fryers are preferable for more delicate items, like fish.

Fryers offer either dial or computer-controlled thermostats, with the latter automatically turning the fryer on and off for added temperature consistency. The more advanced the controls, the tighter the fryer’s variance or tolerance.

With electronic controls, operators receive notification when the preset cook time expires. Automatic lifts raise the baskets out of the cooking oil, halting the cooking process. Self-cleaning fryers have stainless steel nozzles that attach to the basket hanger and connect to the plumbing system for easier cleaning of the vat’s interior and fryer’s heat exchanger.

A number of energy-efficient fryers are available. Some utilize a blower system powered by an electrical motor, which pushes or pulls heat from combustion through the unit. As a result, these fryers do not solely rely on gas pressure to heat the tank’s metal and the shortening. Other models have premix burner systems that accurately mix air and gas for maximum energy efficiency. Fryers with alternative baffling designs rely on the natural vacuum in the tank that, through its exhaust, slowly pulls flames within the unit. There also are models that employ self-cleaning burner systems that perform daily preventative maintenance and keep fryers running at peak efficiency levels.

Purchasing Considerations

Operators should weigh a variety of factors when purchasing a commercial fryer.

For example, consultant Brent Hall, principal/vice president, Clevenger Associates, Puyallup, Wash., won’t specify a fryer without built-in filter drawers. These make operation easier and safer, he feels.

“It’s also important to pay attention to oil recovery systems,” Hall says. “Operators can have central oil filtration and recovery pumped through the kitchen. Some love these systems and others don’t, but they’re a good idea for larger facilities.” For these systems, operators have to plan for piping to the fryer and for room on the wall to house the hose.

Sizing represents another key factor when choosing a fryer. “If it’s a small cafe, one fryer may be required, unless two conflicting products, like fish and fries, are being prepared with it,” says Hall. “In that case, it’s necessary to have separate tanks, so a split tank fryer will fit in a single footprint but accommodate two types of products without contaminating the oil.”

Because it’s important to keep fryer oil as clean as possible for the highest product quality, the filtering processes should operate when and how they’re supposed to. Clevenger specifies fryer covers to cover tanks, but these don’t often get used. “Fryer placement is critical,” says Hall. “This equipment cannot be located by open burners or broilers without a 12-inch spreader in between to protect from splattered oil.”

Cleaning & Maintenance Considerations

Fryers show a number of signs when they reach the end of their service life. The main indication: a leaking tank or well. Look for hardened oil beneath the fryer and behind the unit’s door. Carbon build up will not only cause leaks, but it will also impact the fryer’s productivity and can be a fire hazard.

While most fryer components, such as the thermostat, can be inexpensive to replace, vats or tanks are cost prohibitive to install. Oil quality and regular filtering or replacement of oil is very important when using a fryer in terms of product quality. “However, it’s the fry pot life that usually dictates its service life,” says Don Thompson, service technician for Baltimore-based EMR. “That’s seven to 10 years.”

If it takes longer for a fryer to heat to a ready temperature or it has difficulty maintaining that temperature during normal use, it should be serviced. “Visual inspection of the fry pot should include looking for signs of oil leaks or anything that affects frame integrity, such as rust, dented sides or bent supports,” says Thompson.

Cooking at too high a temperature also can compromise the unit. “Just because the thermostat can be turned up to 375 degrees F, satisfactory results can be achieved at 325 degrees F to 350 degrees F,” says Thompson. “Your oil will last longer, which could result in lower operating costs.”

Faulty thermostats need attention, since they will set off a fryer’s high-limit sensor. If the fryer temperature exceeds 400 degrees F and the thermostat is not working, the high-limit sensor will shut down the fryer. If both the thermostat and high-limit sensor are not operable, this can cause a fire. Thompson also recommends using vat covers when fryers are off. “Light and heat will darken the oil, requiring more frequent filtering or oil replacement, which increases costs,” he says.

Cabinet rust represents another potential indication that a fryer is nearing the end of its service life. This typically occurs when fryer surfaces have regular contact with water. Because costs are high to tear down and replace major fryer parts, a severely rusted fryer will most likely need replacing.

Finally, if temperature recovery time is getting significantly longer, this also may be a good indication that a fryer is reaching the end of its service life.