Innovate Blog
Professional dishwashing in busy foodservice environments

Monday July 31, 2017

Clean and simple: a series of blogs from Cleanline expert Rod Hale.

We asked our Cleanline expert ‘In simple terms, how does my dishwasher work?’

And here’s what he told us…

Cleanline Expert – Rod Hale Twitter – @rodhale2

Cleanline Expert – Rod Hale Twitter – @rodhale2

A lot of money is spent on commercial dishwashers and once they’re up and running they are generally taken for granted, but it does help to know how they actually work.  Once you understand how they function, it’s easier to troubleshoot problems and quicker to get them fixed – meaning less disruption during busy foodservice times.

There are probably as many types of dishwasher as there are models of cars on the road; they’ve been in mass production since the 1950’s and since then numerous improvements have been made to make them more efficient, more economical and kinder to both the user and the environment.  However, just like a motor car with four wheels and an engine, the basics of how they work remains unchanged.

In the world of catering and hospitality there are three distinct types of professional dishwasher.  There’s a small one with a hinged drop-down front-opening door, often found under counters or bars.  These are generally known as “front loaders”, “under-counter” or “cabinet” dishwashers.  Then there’s the free-standing type you find in a much busier kitchen.  With these you must open a spring-loaded door by pulling upwards on a large handle to reveal the rack housing and the wash and rinse arms, one set below the rack of items to be washed, and  one above-these are termed as “hood type” machines.  Finally there’s a bigger machine that automatically pulls multiple plastic racks full of dirty tableware on a track right through the stages of washing, rinsing and drying; these are known as “rack conveyors” and are used in very busy catering operations.

All three types of professional dishwasher contain a tank of water with a heating element at the bottom of it.  This is called the wash tank and automatically heats up to around 55 degrees C when it is switched on.  A powerful electric pump is housed in the body of the machine to shoot this hot water out through jets in wash arms once an electronic signal has been received.  It is into this wash tank that detergent is introduced, mixed with the water and blasted out onto plates, cups and cutlery to get rid of all the residues of food and drinks.

With cabinet and hood type dishwashers, the washing process (known as the wash cycle) is activated when the door is shut; with the rack conveyor, the process starts as soon as the machine is switched on.  The jets blast hot water mixed with detergent directly onto the full racks of dirty cutlery and crockery dissolving fat, grease and dirt.  The hot water goes straight back into the wash tank to be recycled and more detergent is automatically delivered when necessary by small pumps connected by tubes to the detergent container.

With the two smaller kinds of dishwasher, after about a minute you can hear the wash pump stop, and a new, higher pitched pump springs into action.  This part of the procedure is called the final rinse cycle and involves jets pumping super-heated fresh water all over the full racks to flush away any loose food debris and the detergent residue.  The water should be super-heated to at least 82 degrees C because it kills bacteria and sanitises everything being washed so that all the items are safe to use again.  It’s at this stage that another chemical is automatically introduced into the water in tiny quantities – rinse aid. Once mixed with water rinse aids chemical formulation makes everything dry quicker as well as producing that squeaky clean look and feel.

The truth is, the bigger the dishwasher, the quicker it does the job.  If you think of the white goods kind of domestic dishwasher at home, they take around 45 minutes from start to finish – well, professional dishwashers should do exactly the same job in as little as 1 minute.

With the bigger, professional dishwasher machines there’s another similarity to a car and that’s the price!  Just like an expensive car, dishwashers really need to be looked after properly.  That means using products like Cleanline machine detergents and rinse aids whose sheer volume of sales alone prove that they do a great job.  Once you’re with a Cleanline system the quality of the products themselves combine with the support of experienced professionals to give you fantastic results all round.

Cleanline also provides additional resources – like a series of YouTube videos that talk you through how to solve common issues on a professional dishwasher.  Also, the Cleanline e-learning website, that provides auditable COSHH awareness training for free as part of the Cleanline service offer.

Click here to see the core-range of Cleanline cleaning products for the kitchen, washroom and front of house and bar – including the Cleanline dishwasher detergent and rinse aid products.

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