The following information is provided
courtesy of The Catering Equipment Suppliers Association.
Understanding Deep-fat Fryers
a deep-fat fryer, all food floats in hot oil, cooking in the top
two inches of the fryer. This can lead to a kitchen having a
fryer which is too big and heating up more oil than needed.
mistake is to take a particular day when frying capacity is
high, such as fish and chips being popular on a Friday, and buy
a fryer as if demand were that high every day.
industry-wide performance measure of a deep-fat fryer is usually
given in weight of chips per hour the fryer can cope with. On
face value, that sounds a level playing field, but it is not.
Pounds of chips per hour assumes an even demand throughout the
day, which seldom happens. For many caterers there is a huge
burst of demand for chips at midday, so basing fryer needs on
what the output of chips is over an hour doesnít reflect what
the kitchen actually has to produce in a much shorter time than
to consider when looking a chips-per-hour ratings between
different fryers is to ensure that the same type of chip is
being rated by each manufacturer. Fry times will vary
considerably between frozen chips, chilled chips, blanched chips
and the size of chips. The best way of finding out the size and
power of fryer needed is to ask a manufacturer to calculate the
capacity based on your weekly throughput of fried foods.
There is no
clear answer to which is better, both have their own distinctive
advantages. The general rule of thumb is that electric fryers
are cheaper to buy and suitable for low to medium volume needs.
If the kitchen is churning out high volumes of fried product,
particularly chips, then gas-powered fryers may be dearer to
buy, but will cheaper to run. However, there have been advances
in the technology of electric fryers and the operation cost and
performance between gas and electric can be negligible.
costs on gas fryers may be slightly more expensive because of
the need to check the gas system.
inclination is towards gas fired fryers; there are three heating
systems with no clear choice on which is the best option. Tube
burners have wide tubes running across the lower inside of the
fry tank. Inside the tubes are gas jets which transfer the heat
into the oil through the tube wall.
The second gas system
is to have a big bank of gas jets concentrated on the exterior
of the fry tank while the third, is a system using infra-red
heaters, which give a high output of heat.
common to all gas-fired deep-fat fryers is that the rapid
transfer of heat into the oil through a metal wall can lead to
oil burn in the base of the fry tank. This happens when food
debris falls to the base of the tank and carbonises because of
the intense heat. This leads to oil taint and a breakdown of the
The way to
get around this used by most manufacturers is a feature called
the cool zone. This is normally a sharp depression in the base
of the tank which is below the level of the gas burners. Food
debris drifts down through the oil and collects in this cool
depression, which can often be up to 30 deg C below that of the
cooking area of the fry tank. However, the belief that every gas
fryer needs a cool has been challenged with the development of a
high-performance flat-bottomed gas fryer.
In a busy
operation it makes sense to have at least two deep-fat fryers,
once kept exclusively for chips, the other frying anything else.
Electric-powered fryers which have heating elements in the tank
have less of a need for a cool zone, but some do still have them
on the bigger models.
fryers or small counter-top models, the usual method of oil
filtration is the traditional one of a bucket, a sieve with a
tea-towel in it and pouring the oil into the bucket through the
sieve. This is both dangerous and inefficient.
The way high
performance fryers solve the oil filtration issue is to have
in-built filtration systems. Commonly, the oil is released
through the bottom of the tank while still hot through a system
of filters and pumped back into the fry tank. The whole process
takes between three and five minutes and since the most the
operator does is press buttons and open a valve, the safety
risks are almost non-existent.
Alternatively, there are freestanding oil filtration systems
available. Either way, oil should be filtered daily.
Look after it!
A deep fat
fryer is one of the workhorses of the kitchen and has almost no
moving parts and has a low maintenance cost. But that does not
mean that kitchen staff should not look after it.
maintenance job of a deep-fat fryer is the cooking oil. Cared
for, it will last many sessions without the need for changing.
Used carelessly with too high a temperature, a failure to clean
and filter food debris at the end of every kitchen session and
oil can be degraded within a couple of days.
While oil is
the big maintenance issue in a deep-fat fryer, it does not mean
the fryer itself can be neglected. Oil can quickly solidify and
become baked onto the frying baskets. This is not just
unsightly, but can taint the oil. Regular passing of the baskets
through the dishwasher will keep the build-up down, if not
totally eliminate it.
is also a problem in the fry tank and periodic degreasing with a
strong detergent during oil changes will soften the fat and a
non-abrasive kitchen scrubber or plastic bowl scraper will
remove much of it. The fry tank will want thoroughly rinsing
after the use of detergent and if there are electric element or
tubes in the tank, care must be taken not to damage them.
A build up
of sticky grease will happen over time around dials for power
control making them move slower. This puts stress on what are
often plastic fittings and can lead to the dial shearing on the
control pin. If the control dial pulls off, then do so on a
regular basis and clean around the dial. As part of a regular
maintenance cycle by a service engineer, the dials may be
stripped down, cleaned underneath and lubricated with a
long-lasting grease able to withstand high heat without
dribbling away such as lithium grease.
If there are
auto-lift baskets on the fryer, then the lift mechanism should
also be kept clean, but this is another job that can be done
thoroughly on a routine service call.
It is an
engineerís job to ensure that any item of equipment serviced is
left in a clean condition as well as a good working condition.
If the deep-fat fryer has been allowed to become very dirty with
a high build-up of congealed oil on the casing, the engineer may
well remove it, but this is going to reflect in the cost of
servicing. Far Better that a
the kitchen staff do the cleaning before the service engineer
But do not
allow kitchen staff to use abrasive scrubbers or powders on
control dials which could eventually remove the dial setting
marks and bring about the need for a replacement dial.
debris from oil as directed by the manufacturer
Keep fry baskets clean
Use an oil filtration system
Check for a build-up of grease at the rear of the fryer
stainless steel fry tanks with harsh abrasives
Allow a build-up of grease on control dials
Damage tank heating elements during cleaning
Allow staff to knock off excess oil with the size of the fry