What is Blast Chilling and Blast Freezing?
The principle feature of Blast Chillers, Blast Freezers or Blast Chiller Freezers is that they are capable of rapidly reducing the temperature of hot foods (+90°C) to low, safe temperatures (+3°C or -18°C). This means it passes through the 'food danger zone' quickly eliminating the opportunity for harmful bacteria to develop and multiply (bacteria multiplies fastest between 5˚C and 63˚C).
A blast chiller rapidly lowers the temperature of hot food from +70°C to +3°C in just 90 minutes. Williams blast chillers can accomodate higher starting temperatures of +90°C, offering the same cycle performance, down to +3°C in just 90 minutes.
The advanced 'Airsmart' system in a Williams product blast chills in three directions simultaneously, ensuring even chilling and eliminating dehydration time after time. Even delicate foods are cooled without damage and maintained in the best possible condition.
A blast freezer rapidly reduces the temperature of hot foods from +70ºC down to –18ºC in 240 minutes. Williams blast freezers can accomodate higher starting temperatures of +90ºC, offering the same cycle performance, down to –18ºC in 240 minutes.
The process makes it easier for caterers to comply with Food Safety and Temperature Control Legislation too. In fact, many caterers are using them solely for that purpose, and in doing so are performing a very simple cook-chill operation.
What is Cook-Chill?
Cook-chill is a simple, controlled system of advanced food preparation designed to provide more flexibility in foodservice. The technique involves the full cooking of food, followed by very rapid chilling and then refrigerated storage, at carefully controlled temperatures, for up to five days. The food must be regenerated (reheated) before service.
A well-managed cook-chill system is simple to operate and absolutely safe – so long as food safety guidelines and HACCP regulations are followed. Cook-chill systems have the added benefit of maintaining food quality, nutritional value, flavour and appearance. Installing a cookchill system also offers the caterer the potential for added flexibility, productivity and profitability
Read more about the cook-chill process here.
When to use a Blast Chiller or Blast Freezer?
Blast chillers and blast freezers are the perfect choice for caterers within every sector who cook and then chill food such as hospitals, pubs, airlines, schools, restaurants and events, to name but a few.
There are many advantages of implementing a cook-chill system using a blast chiller or freezer, including:
- Improved kitchen efficiency and productivity
- Menu extension
- Reduced food waste and improved portion control
- Reduced labour costs
- Fantastic opportunity for expansion
- Increased profitability
- Guarantee of food safety and HACCP guidelines
At Williams, we supply a range of sizes from reach-in 10kg undercounter blast chillers and blast freezers to roll-ins that are able to handle up to 320kg of food. For even larger capacities, we have developed a range of modular roll-in blast chillers. We also offer specialist models such as our WTBC70 roll-in for Rational and Lainox trolleys.
More on our chiller freezer ranges can be found here.
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Blast Chilling and Blast Freezing: Energy Efficient Tips
Our latest generation of blast chillers, freezers and chiller freezers have been developed under Williams’ Greenlogic initiative - designed to offer the most sustainable, energyefficient and ‘greenest’ models on the market.
Food safety is vital
HACCAP compliance is a must with blast chilling. Before buying a unit that uses less power ensure it’s able to blast chill food in an acceptable time. Regulations state that the core of the food must be chilled in 90 minutes and frozen in 240 minutes. For added flexibility consider a unit that can chill from +90°C rather than the standard +70°C.
Choosing Natural Refrigerants: Choosing a blast chiller operating on natural, energy efficient green refrigerants that are 100% CFC free will substantially reduce energy costs.
Before you begin: Ensure that the blast chiller or freezer is switched on and is at the correct temperature (3°C for chilling / -18°C for freezing) before hot food is loaded, otherwise the refrigeration system will be overworked. As well as being less efficient to run there’s the risk that the cycle may not complete correctly.
Use a food probe: Using a food probe to control the blast chill cycle can save energy by stopping the blast chill cycle as soon as the food reaches the correct temperature.
Air distribution: Having even, all round air flow not only ensures uniform chilling and minimises the risk of damaging the food but also reduces energy use.
Self-diagnostics: With any unit maintenance is key to ensuring your product runs efficiently for the life of the unit. Blast Chillers are available with self diagnostics, which mean service engineers can quickly find a fault and correct it. Maintenance reminders such as condenser cleaning lights are also invaluable in keeping your refrigeration running smoothly.
Keep it closed: Once the blast cycle has started, do not open the door, for example to add more trays of product. The food already in the unit will be subjected to warm air, while the food that is added won’t get the full blast cycle. This not only reduces the efficiency of the unit but, food safety will be compromised.
Don’t cover food: Don’t cover food in trays in the blast chiller or freezer, it will compromise the efficiency of the blast cycle. Modern blast chillers and freezers have special airflow designs, such as Williams’ AirSmart, which protect even delicate food, so there is no need to cover it.
Storage mode: Many modular reach-in units now come with a storage mode. The energy savings available for this can be sizeable as it negates the need for a separate unit to hold products at the appropriate temperature. This is especially true for high volume modular units.
View our range of Blast Chillers and Blast Freezers here.