Ice Machine Hygiene

Where hygiene is an important consideration, eg for food manufacturing applications, it must be considered at every stage.

1. The ice machine and storage must be of the correct type and specification.
2. The location should be analysed for potential problems.
3. Any additional options to suit the application must be considered.
4. Operational procedures should be put into place to ensure good working practice.
5. Cleaning, sanitation and maintenance should be planned

The picture to the left shows 2 x UBE5.000 RV models feeding an AS500 mini silo.

1. The correct ice machine

When hygiene is important, Ziegra would recommend a machine with a single pass water system. This means that water enters the machine from the mains, travels through the machine in a single path and exits the machine as ice.

Granular flake ice, Nugget ice or StreamIce machines are of this type and are our standard recommendation for food applications, particularly when the ice is to be added into the food as part of the recipe.

In other types of ice machine, such as scale ice, the water is allowed to loop back to a water reservoir from the ice making chamber continuosly, resulting in any airbourne contaminants being entrained in the return water and building up in the storage tank.This makes scale ice machines intrinsically susceptible to microbial contamination and notoriously difficult to maintain in a sanitary condition.

Trapped foreign particulates and mineral deposits inside an ice machine can provide an ideal environment for microbiological organisms to breed. 

This is why all our hygienic ice machine models come with an external water filtration system as standard which is fitted inline between the site water supply and ice machine. These unit filter most particulates above 1 micron from the water and have an element that helps to slow down the rate at which mineral deposits form internally within the machine. This system builds upon the intrinsically hygienic nature of these machines and provides a good foundation for hygiene as standard.

When Ziegra engineers are designing these models, their first consideration is hygiene and how it can be enhanced. An example is the level control system in the picture on the right, this is a non-contact design, that sends a beam out to the ice and receives it back in order to measure the level of the ice without touching it. Some other types of sensor risk touching the ice, again introducing the possibility of contamination.

Small thoughtfull design decisions like this add up to reduce the contamination risk during operation.

Hygiene +

To capitalise further on this foundation, Ziegra also offer a number of options to increase the hygiene levels further and help to maintain this standard during normal operations.

Auto water drain. This is standard on units from 1,500kg per 24 hours and an option on the smaller models. This option automatically drains the water tank inside the machine when the machine is switched off to prevent nucleation.

Flushing, cleaning and disinfection systems. These options offer various levels from simple flushing, to full cleaning, disinfection and flushing. They can cycle automatically at user designated times, or at the push of a button when convenient.

UV filtration. This offers sterilisation of the incoming water supply by means of a powerful UV-C field. It will kill 99% of microbes in the water, slowing down the rate at which these microbes enter the machine through the water supply.  

The location.

When planning for an ice machine installation, if hygiene is a primary concern then the location where the equipment will be installed is also an important factor.

General area condition. The area should be clean, dry, well lit and in good repair. Light fittings, dusty pipes, flaking paint etc above the machine are all contamination risks and should be eliminated. The area should subsequently be kept clean and tidy at all times.

For more information on specifying an ice machine for a particular site location, click here

Operational procedures.

While ice contamination can occur through the water and from airbourne sources, another route is from poor operational procedures.

The ice machine external surfaces should be kept visibly clean and chemicals, rags, tools etc never be stored on top of the machine or on any nearby surface that it could be accidently knocked into the ice.

All tools and utensils used to handle the ice must be kept free from damage and clean, always handled by the handles and never stored in the ice.

Operators handling the ice should be equipped with appropriate hygiene PPE such as hairnets and should follow personal hygiene rules such as handwashing to avoid human contamination.

When filling open containers or boxes, lids or shields should be used during the filling cycle to prevent the ingress of foreign objects into the ice.

Cleaning and maintenance.

Regular cleaning and maintenance is vital to keep any ice machine reliable, efficient and hygienic. Even if all the above is followed, it will only buy you time if proper cleaning and maintenance are not carried out regularly. It may take many more months to reach a poor state of hygiene, or many more years to reach a poor condition than a less well specified machine, but eventually it will happen.

The ice machine external surfaces should be inspected frequently by the hygiene operatives and kept in a visibly clean condition.

Periodically the ice machine internal water pathways should be flushed through with Ziegra sanitiser to prevent colonisation of the machine by microbes. This should be done as a minimum every six months, but more frequently if conditions require. If you are following the guidelines, but find the machine is being colonised more often than you would like, or you just want to extend the periods between sanitation cleans, fit a UV filter into the water supply as this is where most microbes enter the machine.

Annually the machine should be serviced by Ziegra qualified engineers, who will strip down the freezing unit and mechanically clean any scale deposits that may be forming and replace all wearable parts. Contracts are available from the Ziegra service department.