FAQ’s Answered – with Hoshizaki UK’s Technical Manager, Stuart Kayes

In this blog post, we speak to our technical guru – Stuart Kayes – as he celebrates his double decade anniversary by answering some FAQ’s surrounding refrigeration and ice machines.

How can I safely blast chill/freeze foods, whilst maintaining food quality?

Only fast, controlled reduction of the core temperature of a cooked food item makes it possible to preserve both the natural goodness and the prevention of the accelerated growth of harmful bacteria at temperatures between +70°C and +10°C.

Blast Chill

This is achieved through strict process times:

Chill = +70°C and +3°C in 90 minutes.

The Hoshizaki range of blast chillers bring food items through this high-risk temperature range in a controlled process cycle, helping to preserve natural vitamins and maintain the appearance and taste of the food.

Blast Freeze

Blast Freeze = +70°C and -18°C in 4 hours.

If a food item is to be stored for a longer period of time, it must be shock frozen to a minimum of -18°C. When using a commercial blast freezer, a core temperature of -18°C is reached within HACCP requirements of 4 hours. During this timescale, ice crystals that form will be small, known as micro crystals. These micro crystals are less damaging and do not adversely affect the quality, nutritional value, and structure of the food item.

What is the difference between climate class and energy labelling?

Climate Class
Climate class is the environmental conditions by which an appliance has been tested (in temperature and relative humidity, RH).

Climate class 1 is the lowest and climate class 5 is the highest. Therefore, it is important that a customer not only looks at the energy label on a refrigerator, but the climate class ranking too.

To efficiently run in a hot and humid professional kitchen, operators should be looking at a minimum of climate class 4 tested appliances (30°C ambient temperature and 55% relative humidity) or ideally the top-level climate class 5 (40°C ambient temperature and 40% relative humidity).

The Climate Class is just one factor that determines a products energy label.

Energy Labelling
An energy label displays important information on the energy efficiency of your product including energy class, annual energy consumption, net storage capacity and climate class.

All commercial refrigerators receive an energy rating between A+++ to G, with A+++ being the most efficient product of its class, and G being the least efficient. All commercial refrigeration manufacturers test products to the same criteria.

The EU energy label is an important tool for helping catering professionals make an informed decision when purchasing commercial refrigeration.


What ways can I boost savings further?


Operators can reduce their energy bills and prolong the life of their refrigerator simply by implementing more efficient practices such as:

  • Keeping the refrigerator door closed, so energy is not wasted. Some busy kitchens could be opening refrigerator doors over 120 times a day which can become costly and unsafe.
  • Placing warm food inside the cabinet will raise the internal temperature and should always be avoided. Products should only be placed in a refrigerator or freezer at the intended storage temperature. To ensure food safety blast chillers/freezers should be used to reduce the temperature in a safe and controlled way before storing.
  • The incorrect positioning of a cabinet can drastically effect energy efficiency and its ability to run reliably. Wherever possible, refrigeration cabinets should be located in well-ventilated areas away from direct sunlight or heat sources such as ovens and hobs and not in outdoor or unheated areas.
  • Implementing a planned maintenance schedule to ensure equipment is checked and serviced regularly can save operators future repair costs and will improve day to day efficiency and avoid unexpected breakdowns.
  • Regularly review the performance of old cabinets. Upgrading often allows for a venue to cut down on energy bills and servicing costs whilst adapting to changes in menu or capacity.

How can I keep my ice machine in tip top condition?

Ice is classed as a food product, and must be produced, stored and handled hygienically. Following these steps will allow for a safe ice making and serving process:

  • Ensure all staff are trained on how to use the ice machines and are aware of the risks of contamination.
  • Empty the ice bin at least once a week for cleaning and sanitisation.
  • Regularly clean and sanitize all scoops, tongs and buckets used to handle the ice. Do not store within the ice bin itself or other open areas.
  • Customers should not have access to the ice storage bins and buckets to avoid cross contamination from untrained personnel.
  • Make regular checks to ensure the machine is in good condition, especially the following:

1.Door gasket is in good condition and sealing correctly.

2.The condenser air filter screen is free frost dust/dirt.

  • Deep clean your Hoshizaki ice machine at least once a year.
  • If the machine is fitted with water filters, these should be replaced every year to prevent scale and improve flavour and remove odours from the water.

For more information on cleaning and maintenance guidelines please download the machine user manual from the Hoshizaki website