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The following information is provided
courtesy of The Catering Equipment Suppliers Association.
Understanding
Warewashing
Warewashing
equipment is the collective industry name for dishwashers and
glasswashers. It derives its name from glass “ware” and table
“ware.”
A common
question from caterers is why can’t they use the same machine
for both glasswashing and plate washing? The answer is you can
and very small establishments cannot justify the cost of a
dedicated glasswasher and dishwasher, but there are problems in
using the same machine for glassware and tableware. The wash
time for glassware is very short, so putting glasses in with the
longer wash cycle needed for tableware wastes energy.
Food debris
from tableware can easily cause smears and spots on glassware,
leading to the need for hand finishing or re-washing. Even
putting glasses in the washing machine on their own following a
tableware washing cycle can still produce soiled glassware.
Dishwashers are often programmed to do a pre-rinse cycle to
clear loose food waste stuck to plates and may have a high
finishing hot rinse to aid sanitisation.
Types of
machine available
Glasswashers
Glasswashers
tend to be front-loading compact machines for small to moderate
usage of glassware, often fitting under a counter or on a bench
in a preparation area. Being compact leads to fast turnaround of
soiled glasses, avoiding the need for heavy stocking levels.
While they are often sited underneath the bar because of space
restrictions, it is better to use the bar area for retailing
rather than glasswashing. Busy pubs and bars may need to move to
a pull-down hood machine which enables rapid washing of a large
volume of glasses.
Cabinet
dishwashers
Dishwashers
start with compact machines, which look and work in a similar
way to glasswashers and are designed to fit on a bench in a
back-of-house cleaning area, still-room or satellite kitchen.
Pull-down hood
dishwashers
The next
stage up in machine design is a pull-down hood machine. These
are more powerful, faster and are manually loaded with a basket
of soiled tableware. They are usually configured with stainless
steel tabling either side of the dishwasher so while a basket of
dirty tableware is being washed, another basket of dirty
tableware is being loaded ready to go in and a washed basket on
the other side of the hood washer is waiting to be emptied. This
gives a continual cycle of plate washing.
Rack conveyor
dishwashers
These work on
a pass-through system where the baskets of soiled tableware are
on a conveyor belt which passes through the washing machine,
going through wash zones which start at pre-rinse, go to hot
wash, then hot rinse and come out on the other side of the
conveyor ready for stacking away.
Flight
dishwashers
These are a
semi-automatic dishwashing system, similar in principle to rack
conveyor systems, but very much bigger. They are designed to
cope with huge volumes of soiled tableware which might be found
in a university or hospital kitchen, an airline food production
kitchen, large staff feeding facility or a conference and
exhibition centre.
Which size
of machine to choose
Many small
to medium businesses underestimate the capacity of warewashing
machine they need. The big mistake is looking at the overall
daily throughput
and basing
machine size
choice on
that. This is to ignore there are always peak demand times in
the day when tableware and glassware is needed very quickly.
Also, buying a machine for current needs makes no allowance for
an increase in business. The safest way of avoiding buying the
wrong size machine is to ask manufacturers for advice.
Questions to
ask before buying
There are
strict national regulations on how dishwashers and glasswashers
should be connected to the water main to prevent contamination
of the mains water system through accidental backflow of dirty
water. Some cheaper machines may not fully comply with water
supply regulations, involving costly later modifications. Check
the machine complies.
Ask about
the type of steel. All warewashing machines offer stainless
steel washtanks, but there are different grades used in
manufacture. The best is Grade 304, much more
corrosion-resistant than the cheaper 430 grade stainless steel,
though both look the same.
Ask about
noise and heat emissions. Double skin casings will reduce noise,
operating cost and be cool to the touch.
Study the
energy and water consumption performance. What may seem a cheap
machine to buy could prove to be a very expensive machine to
run.
Ask advice
on the fitting of a water treatment system to prevent limescale
build-up in the internal pipework of the machine. Water
treatment is essential in hard water areas and recommended in
other water areas.
Be very
specific about the availability of spare parts, the turnaround
time for spares and what are the service options offered with
the machine.
Look After It!
Warewashing
equipment is often shunted to the far corners of a kitchen and
since in all but very small catering businesses is operated by a
kitchen assistant rather than a chef. Professional warewashing
machines are built to take hard work, but a lack of care during
use can be a potential source of unplanned and unnecessary
maintenance cost.
Responsibility for supervising dish and glasswashing equipment
should lie with a senior kitchen manager, who while not involved
in daily operation of the machine, will ensure correct operation
procedures and in-house maintenance as set out by the
manufacturer. Warewashing equipment has heavy use during every
service period. It is built for hard work, but not for neglect
or abuse.
The biggest
drain on maintenance cost of a warewashing cabinet is the
failure to fit a water softening system. It is normally an extra
item to a new machine, but it is not a luxury. Mains water
contains dissolved salts which when heated break out of the
water and attach to metal. This will be heating elements and
pipework. This familiar furring up of metal increases energy
costs and in furring up of pipework in a dishwasher can lead to
serious internal damage.
Fitting a
water treatment system in hard water areas is essential, but is
also strongly recommended in soft water areas, since all water
contains dissolved salts and water is passed around the national
water pipeline. Fitting a water treatment system to a
glasswasher will also reduce the risk of streaking and smearing,
which is mostly caused by dissolved salts. It will almost
certainly be a requirement for a manufacturer’s warranty to be
valid on new equipment and for a service contract.
There are relatively few moving parts on a
dishwasher, the main two being the pump that circulates the
water around and the wash arms. Fitting a cheap pump is
invisible and it may even deliver a comparable time for the wash
cycle to an expensive unit, but it will break down quicker and
more often than a well-made pump.
The wash arms
spin on bearings can wear out and cheap wash arms themselves can
get damaged or broken if poorly designed. Spray jets may be
individually replaceable, but on cheaper machines it is often
the whole wash arm which needs replacing. These points need to
be considered when during a routine maintenance visit by a
service engineer it is reported that a part needs replacing and
there are several spare price part options available.
All
warewashing machines have filter systems to trap food debris,
but a dishwasher is not a waste disposal system and excess food
waste should be scrapped first into a dry waste bin and
preferably with a pre-rinse using either a sink hose or a simple
dip and scrub in a sink or by using a waste disposal unit.
Larger dishwashing system are built to deal with food residues,
but with smaller cabinet machines, allowing excess plate waste
to go into the cabinet could cause clogging of the water filter
system. Rice may seem a benign food, but it notorious for
clogging filter systems.
Under-performance of dish and glasswashing machines often has
nothing to do with the machine, but with the quality of the
detergents being used. Cheap detergents will not damage a
washing machine, but can lead to double washing because the
plates and glasses were not clean.
Like any
item of catering equipment, regular servicing is the key to
keeping warewashing equipment running effectively.
In brief
Do
Fit a water
softening system
Check the detergent dosing levels
Scrap plates thoroughly before washing
Train staff on good work practise
Check and un-block spray jets
Don’t
Use cheap
detergents
Use a dishwasher as a waste disposal unit
Neglect to clean filters
Mix dirty plates and dirty glasses
Overload the machine
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