Choosing a deep-fat fryer

As prime cooking equipment goes, the deep-fat fryer is a simple piece of kit: an oil tank, a basket and a heat source. And while it may sound like an easy buying decision, the choice becomes as cloudy as three-week-old cooking oil when the man in the showroom asks for a decision between gas and electricity as the energy source.

Joe Goggin runs National Energy Costs, which advises catering businesses on energy efficiency and energy buying. He says that while there are many variables when choosing gas- or electric-powered deep-fat fryers, there is one inescapable truth when it comes to buying energy: gas is cheaper.

The key question to ask of someone trying to sell a deep-fat fryer, says Goggin, is: "What is the running cost per kilowatt hour?" "This strips it down to what the energy cost is. That is very important, though it doesn't tell you how efficiently the energy you are buying is being used," he explains.

That is part of the case put forward in favour of electric fryers by Malcolm Morris, national account manager with Valentine. He says that although gas is cheaper, there are other factors in the choice. The heating element in electric fryers is immersed in the oil, whereas with gas it is often burners underneath the tank, which need venting.

The ventilation cost of gas fryers is definitely underestimated, according to Paul Cudworth, UK director of sales for Enodis, distributor of Frymaster fryers. "It's not just about the extraction of cooking fumes, it is the carbon monoxide extraction. As a rule of thumb, you will need 40% more ventilation with a gas fryer than with an electric fryer."

It is when the volume demand on frying becomes high that gas can begin to steal the edge. The advantage of gas is that oil temperature recovery time is often better than with electric. Recovery time is the technical term for how long the cooking oil takes to regain optimum cooking temperature after frozen or cold food is immersed in it.

Neil Roseweir, development chef with Falcon, believes kitchens often underestimate the cost and quality implications of oil recovery time. His point is that while oil is thought by chefs to be no more than a commodity purchase, the annual cost of oil for a kitchen is huge, and rapid recovery time is crucial in delivering crispy food with minimal oil absorption and minimal oil loss.

The way some high-powered gas fryers deliver rapid heat recovery time is through forced-air burners which, like turbochargers, inject air into the burner to allow a higher combustion rate and consequently a higher heat output. The downside to this massive gas-fired heat is that it can lead to tank damage and leaks. On a top-end gas-fired fryer don't be surprised if the replacement and repair bill for a split fry tank is as much as £1,000.

Cleaning is not a major issue between gas and electric, but it is a consideration. In a gas fryer with fixed burner tubes inside the fry tank, food debris will collect under the burner tubes and, while cleaning is not difficult, it's not as simple as in an electric fryer or a gas fryer with under-tank heating. This is a point made by Nick McDonald of Lincat. He says that with in-tank burner tubes cleaning requires a disciplined regime in the kitchen, whereas under-tank heaters or removable electric elements make cleaning of the fry tank far easier.

Another hidden cost of gas is in the installation. Les Starling, service manager at the Parry Group, points out that while a gas fryer needs a Corgi-registered commercial engineer to install the gas connection, with an electric fryer it is often just a matter of plugging in. And although the supplier of the gas fryer will usually arrange installation, it is a cost normally passed on to the caterer either directly or reflected in a lower purchase discount.

And servicing must not to be forgotten when calculating the whole-life cost. Mike Davis, field technical manager at equipment distributor Olympic Catering Equipment, says there is a noticeable difference in servicing costs between gas and electric, with gas being more expensive. He says there are gas pressures to check, flame-failure devices, and the cleaning of burners and pilot lights.

This compares with a much simpler servicing routine for electric fryers, the main item to check being the overheating microswitch, which automatically cuts out the heating element should it be exposed to the air through a depletion of oil or by the fryer being accidentally switched on when empty.

Buyer's check list

aConsider your present and future frying requirements and always buy the size to suit this need allowing for future expansion.
aCheck production timings of chips.
aAre any essential accessories such as fry baskets and lids included in the price?
aCan it be dismantled for cleaning?
aHow easy is it to drain off the oil for filtration?

Using solid fats for deep-frying

The frying medium is also a consideration in choosing your energy source for a deep-fat fryer. While liquid oil is the most popular, there is still a big following for solid fats, mostly based on palm oil, but also using rendered beef fat as a flavour enhancer.

Using solid fat can cause maintenance problems with electric fryers which have the heating elements inside the fry-tank, according to frying consultant Barrie Bullimore, who works in the fast-food sector advising on cooking oil management. Bullimore says an oil change means dropping big lumps of solid fat into the fry tank, which can easily lead to the elements being exposed to air as they heat up. "Electric elements are not designed to be heated without the presence of oil, and this can cause early failure of electric elements which have been allowed to go beyond the operating temperature. Anyone who wants to use electric power and fry using solid fat must make sure the new fat is broken up and packed tightly around the elements so as they begin to heat up they are permanently coated in liquid."

The more top-end electric fryers get around the element burn-out problem with solid fats by having a melt cycle, which typically will keep the elements at 90°C. This will melt the fat slowly, preventing element damage and prolonging oil life by not burning it in localised areas.

It's worth remembering that this problem with electric fryers and solid fat is worse in winter when the fat will have set very hard.

Contacts

Angelo Po 0115 944 0622
Bonnet 01494 464470
Fagor 01732 860360
Falcon 01324 554221
Frymaster 0114 257 0100
Hobart 07002 101101
Lincat 01522 875500
National Energy Costs 01772 615815
Parry Group 01332 875544
Valentine 0118 957 1344