Fryer Categories and Types
To begin, it’s important to understand the four main categories of fryers on the market.
- Deep-Fat Fryers
The most popular type of commercial fryer in foodservice. Operating in gas (liquid propane or natural) or electric and available as counter units, freestanding floor models, or multiple battery units.
Countertop fryers save floor space by resting on top of worktables or counters and are generally cheaper than their floor model counterparts. Power input for countertop deep-fat fryers range between 45,000 to 75,000 BTUs for gas models, or 5 to 21 kW for electric. Shortening capacities typically range between 15 and 30 lbs. Production output is between 25 and 60 lbs. of french fries per hour. Drop-in fryers work in tandem with countertop units to help conserve kitchen space. Countertop and drop-in models are ideal for small kitchens, food trucks, or concession stands.
For high volume operations needing to produce more than 60 lbs. of french fries an hour, you’ll want to opt for either a freestanding floor fryer, or a battery of fryers. Gas floor fryers usually range in input from 80,000 to 200,000 BTUs an hour while electric models range between 12 to 42 kW. Shortening capacities range between 35 to 210 lbs., capable of cranking out 60 to 300 lbs. of french fries per hour. Floor models are geared more towards fast-paced restaurants, cafeterias, or other industrial kitchens.
Floor models can also be built into what’s referred to as a battery of fryers for a high production output. Installing batteries entails banking several fryers together for a continuous line. Though this takes up more space, it also allows you to customize and accommodate production demands specific to your establishment. Fryer batteries also alleviate the need to order multiple units separately.
Deep-fat fryers come with either one or two wire baskets constructed of either nickel-plate or stainless steel. These are placed outside of the frypot and used to load product into the shortening to cook. When cooking is complete, these baskets are removed and excess shortening is drained to finalize the product for service. Most fryers also come with thermostat controls and a timer.
- Pressure Fryers
Though less common than deep fat fryers, pressure fryers are still important to note because they carry a distinct set of benefits. Pressure fryers are ideal when the speed of cooking is critical, typically used to prepare fried chicken. Unlike the open-pot design of traditional deep fat fryers, pressure fryers use a cover to seal in the shortening with the product loaded inside.
Once the food is inserted and it begins to heat, its natural moisture vaporizes into a steam barrier that slows the penetration of the shortening. After a short amount of time, this steam begins to generate pressure (most pressure fryers operate between 5 and 12 PSI). During this process, the food retains most of its natural juices. As the pressure continues to build, the shortening experiences minor turbulence that results in the food gently tumbling to create an even and thorough fry.
Some advantages of pressure frying include: the retention of natural juices; foods come out less greasy due to less shortening absorption; less absorption means less shortening used, thus reducing some operational cost.
- Conveyor Fryers
Conveyor fryers are great for high volume sites like theme parks where concession stands need to produce large supplies in short periods of time. These units operate with a conveyor system that automatically moves products through the cooking cycle. The food is placed on one end and then carried through the shortening-filled tank, depositing freshly fried at a collection station. The fry basket then returns to the front for another round. Speeds can be increased or decreased, depending on the demand. This allows the operator control over the cooking process while still using automation for high and efficient production. Some high efficiency models can produce up to 100 lbs. of fries per hour!
- Air Fryers
Air fryers are smaller countertop units that use a minimal amount of oil in a rotating drum that’s mounted inside a closed compartment to fry single portions or product in smaller batches. They use convection heat technology to force air through to heat frozen products. The big advantage of these units is they don’t normally require placement under a type I ventilation hood, and they don’t release high amounts of grease-leaden vapor, making them ideal for bars, small snack shops, and other areas without heavy-duty utilities or ventilation.
One of the biggest determinants in deciding which fryer to go with will be the amount you’re looking to produce. This will ultimately determine the size you’ll want to go with (see above for the differences between countertop and floor model units). The fryer’s tank capacity will inform you of how much oil it can hold, and therefore how much you’ll be able to cook at a time. Some manufacturers rate their fryers based on tank capacity, while others are based on production output (again, typically notated in terms of pounds of french fries per hour). Generally speaking, an efficient fryer will be able produce a volume of either 1-1/2 to 2 times the weight of oil it holds. For example, a 50 lb. deep fryer should in theory produce 100 lbs. of fries an hour.
Fryer Design: Tube vs. Open Pot
Commercial deep fryers come in varying designs that serve different purposes. The two most notable are a tube design and an open pot design.
Tube-type deep fat fryers are designed with a series of tubes welded into the frypot near the bottom of the vat, housing gas-fired burners that evenly heat the oil they’re submerged in. These are the most popular type of restaurant fryers because of their versatility, able to fry a variety of foods. Other advantages over fryers with an open pot design include energy efficiency and a large cold zone that helps preserve the life of the oil, making them ideal for breaded foods that leave behind a lot of excess sediment. On the other hand, they are also known to be challenging to clean and use a high percentage of oil. These tubes also hold baffles to ensure the most efficient heat transfer. These tend to weaken over time, which makes lower-end models more prone to failure.
Open pot type restaurant fryers are better for foods with lower degrees of sediment such as french fries or frozen items. They don’t feature any tubes or burners in the oil themselves, which makes them much easier to clean. The cold zone is smaller, which is why these units can’t handle as much sediment. In lieu of tubes that house burners, these units feature a heating element on the outside of the frypot, and are usually gas-powered. In addition to an enhanced cleaning experience, other advantages to open pot designs include a reduced amount of oil necessary for the cold zone, and burners that are more reliable because they don’t require baffles which means they’re less prone to breaking down. However, they’re not considered as energy efficient as tube-types, and they have a much lower sediment capacity.
Gas vs. Electric
As noted, many models are available in either gas or electric. There are pros and cons to each. For many, the choice ultimately comes down to the cheaper option, and this is dependent on location. Some operators are charged less for utilities, so to them a gas fryer is ideal, while others experience lower energy costs, so an electric deep fryer may suit them better. Regardless, you must know how your kitchen is naturally outfitted before making a purchase. For gas fryer purchases, know whether you have a natural gas hookup at the ready, or if you’ll need to opt for liquid propane. For electric commercial fryers, understand the voltage (traditionally 208V, 240V, or 480V) and phase (single or three) requirements. Some electric units may need to be hardwired directly into the building’s energy supply, while others may simply plug right into an outlet with very little installation hassle.
The primary advantages of electric deep fryers include:
- No need to worry about gas leaks
- Simple installation
- Faster recovery times
- Smaller models are easier to transport
- Considered more energy efficient, especially during heat transfer thanks to submerged burners
On the flip side, many advantages to gas fryers include:
- More options are available for the frypot shape
- Traditionally more common, so employees are more likely to already be familiar with their operation
- Heats and cools down faster
- Not as affected by power outages
Fryer Oil and Filtration
The type of oil you use in the frying process is crucial. Shortening is expensive and requires regular filtering to extend its life to ensure a high quality of food. One key component to use for comparison purposes is how long the fryer can make the shortening last. Efficient fryers that notate longer shortening life may cost a little more up front, but will save money down the road.
No shortening will last forever, but there are a few areas to be conscientious of as they increase the rate of shortening deterioration.
- Exposure to oxygen is the primary cause of shortening break down.
- High heat destroys shortening. Some shortening brands are formulated to withstand temperatures between 200°F and 400°F.
- Various contaminants like acid, food particles, water and salt can affect the shortening life.
- Detergent residue left over from improper cleaning will also have a negative impact on the shortening.
There are many ways to be proactive about extending the life and getting the most bang for your buck out of your shortening. A solid filtration system will have the biggest positive impact. Many units feature built-in filtration. These traditionally cost more but are worth it in the long run. Filter systems remove contaminants that break down oil and can have an ill-wanted effect on taste. Add-on filter systems are available if your unit doesn’t have one built-in. These are often mobile and can be used to service multiple units that are equipped with a quick-disconnect hose, but they also pose more risk to employee safety and require additional labor.
Other factors that can increase the longevity of your shortening include:
- Units with a larger tank capacity can hold more shortening. Once the shortening is initially heated to the desired temperature, they tend to maintain it longer.
- Cold zones that are designed into most modern fryer units work to catch food particles and hold them at a lower temperature to reduce burning or carbonization.
- Fryers with a high BTU-input feature faster recovery to the desired cooking temperature after raw foods are added. With a faster recovery time, units don’t have to use high temperature settings to compensate for the addition of cold products. Reduced cooking temperatures save on both energy and shortening costs.
- Sophisticated controls make it easier to maintain the desired temperature. More on control types in the next section.
Here are a few other key considerations to help finalize your fryer decision.
- Control type – Some fryers come with programmable controls for more automation to assist in cooking processes that your operation uses regularly, while others feature solid state or manual controls. With programmable controls, operators can program in multiple factors, such as the temperature and cook time, and control the cooking process with the push of a button, saving on labor while delivering consistent results. Some high-end models even feature options to adjust temperature or the cook time based on the current quality of the oil. Programmable fryers are often the more expensive fryer. Fryers with manual controls, on the other hand, are more cost effective and straight forward to use. However, they’re not capable of automatically adjusting settings.
- Recovery time – As discussed briefly above, the recovery time refers to the amount of time needed for the oil to return to the desired cooking temperate after raw foods are inserted. If the oil temperature decreases too much or fails to rise fast enough, the greater risk of fat absorption and a greasier product.
- Energy Star Rebates - 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. For more information on ENERGY STAR® rebates, click here.
Cleaning Your Commercial Fryer
Regular cleaning and maintenance are crucial to ensure a long product life. Proper oil filtration and cleaning will have a direct impact on the flavor quality of your fried foods. How often you need to filter is based on usage. It is recommended to filter oil at least once a day, but for operations with much higher volumes, it may be necessary to filter more often.
The same can be said for regular cleaning. Most establishments include cleaning as part of the nightly kitchen shutdown. It is encouraged that the cleaner wears high-heat gloves, an apron, and protective goggles for safety. Turn off the burners but ensure the oil is still hot when you begin the filtration process. Otherwise it will start to congeal and solidify.
After the unit is depleted of oil:
- Identify and secure the thermostat probes on the frypot as these are often fragile and can be damaged or lose calibration if hit with a scrub brush.
- Using a fryer brush, which are designed with a bend specifically to assist in the scrubbing of hard to reach burner tubes, scrub excess sediment off the walls and the bottom.
- Ensuring the valve is closed, fill the frypot halfway with hot water, making sure to cover burner tubes or heating elements. Add cleaning solution.
- Set the temperature to 350°F and let boil for 15 to 20 minutes.
- After, turn the thermostat off and drain the water.
- Rinse thoroughly with clean hot water, ensuring the drain valve remains open.
- Dry with a clean towel.
- Refill with oil and secure a cover over the frypot until ready to use.
You can view our entire selection of fryers and accessories here. For any additional questions, call 800.215.9293 to speak with a foodservice expert.