How To Cook Chill: The Process Explained

Cook-Chill involves cooked food being rapidly chilled, using either a blast chiller or blast freezer, and then stored at controlled temperatures.

What is Cook Chill?

Cook-Chill is a simple, controlled temperature system of advanced food preparation designed to provide more flexibility in foodservice.

The technique involves the full cooking of food, followed by rapid chilling and storage at controlled temperatures (for up to five days). When required, the food must be regenerated before service. The production system itself is simple to operate if well managed, and completely safe provided the Department of Health Guidelines on temperature/time controls are followed.

Cook-Chill Systems have the added benefit of maintaining food quality, nutritional value, flavour and appearance.

Installing a Cook-Chill System also offers the caterer added flexibility and management – and of course profitability

Why do I need a cook-chill system?

If you cook then chill food, its temperature needs to be reduced safely from 70°C to 3°C within 90 minutes. If you are freezing cooked food, the temperature needs to go from 70°C to -18°C in no more than 240 minutes. Otherwise you are breaking the law. Worse, you are putting your customers at risk.

This is because bacteria grows most aggressively between 5°C and 63°C – so the food needs to get past this ‘danger zone’ as quickly as possible.

It’s no good putting hot food into a refrigerator or freezer – it won’t cool fast enough, the resulting rise in the cabinet temperature will endanger other food being stored there, and it will overwork the refrigeration system.

The only safe way to comply with the food safety regulations governing the chilling or freezing of cooked food is to use a blast chiller or blast freezer.

What is the difference between hard chill and soft chill?

Blast chillers offer the option of soft or hard chill. Soft chilling is a gentler process that ensures delicate products, such as fish, fruit and vegetables, do not develop ice crystals.

Hard chilling is suitable for denser foods such as meat, casseroles and lasagne. Here the airflow drops below freezing to maintain safety while ensuring the product stays in prime condition.

What equipment do I need for a cook-chill system?

If you are already serving hot food, the only additional equipment you will require for a small to medium sized Cook-Chill operation is a suitable Blast Chiller or Chiller Freezer. You will also need a suitable refrigerator or coldroom (0ºC/+3ºC) for the storage of the finished product.

Williams Refrigeration provides Blast Chillers and Blast Freezers with capacities from 10kg under counter models up to roll-in models capable of Blast Chilling 320kg. Simply work out the volume of food you will be preparing in advance and choose a model that suits.

To find out which model is the most suitable for your operation, consider the type of food you will be blast chilling or freezing, as well as the volume of food you need to produce, calculated in quantity of kilograms.

When calculating volumes remember that you may be producing meals for consumption over seven days but with production in only five days. It is also wise to allow a little extra capacity than you require at the present time, in order to allow for the expansion of your business and changing menus.

Whatever the type of Blast Chiller or Chiller Freezer you choose, it must be capable of reducing the temperature of a 50mm layer of food from +90°C to between 0°C and +3°C within 90 minutes, when fully loaded.

It must also feature an accurate (+/- 0.5°C) temperature display, with a built in food probe featuring digital display. Digital and audible timers are also useful features.

On completion of its rapid chill cycle, the machine should automatically revert to storage mode (0°C/+3°C), until the chilling mode is selected again. This enables the operator to put one load in last thing at night, for example, and remove the chilled product first thing in the morning.

Make sure that the model you choose is compatible with the electrical supply you have. Smaller models will operate satisfactorily on a 240 volt domestic supply.

The best equipment is made from stainless steel. You should also look for a good seal around the door. Poor seals mean an inefficient machine and will cost you money in increased power consumption and less effective to comply with the important times referred to in the Cook-Chill/Freeze Guidelines.

Pay close attention to the design. It should be possible to have easy access to the evaporator compartment for cleaning and servicing.

Look for removable shelf slides and racking. Cabinets with these features are easier to clean.

Automatic defrost and evaporation are essential features to look for when selecting a machine.

Storage equipment

The storage equipment used for holding pre-cooked chilled foods must be designed and used specifically for that purpose. Steps must be taken to ensure that possible cross contamination between raw foods or other cooked products and stored chilled food does not occur.

The store must be capable of holding products at a constant temperature of between 0°C and +3°C, and this should be indicated clearly by a visible temperature indicator.

The equipment should ideally feature an audible alarm which will alert you if the storage temperature reaches unacceptable levels. A temperature recording device is also required.

When selecting storage equipment, allow for sufficient capacity to cope with peak production, as well as room for an efficient stock rotation system. A minimum storage capacity of two days is normal for Cook-Chill products.

Storage equipment will need to be sited in an area that allows for easy access, and must be sufficiently close to the Blast Chiller to ensure that food arrives at the store without risking any fluctuations in the 0ºC/+3ºC chilled temperature - whilst still at the optimum chill temperature.

View our range of Blast Chillers and Blast Freezers here.

IMPORTANT! Make sure your cooking, chilling and storage equipment are all compatible with the containers you use (Gastronorm or designed for Combi ovens).
As with any cooking operation, a Cook-Chill system requires care to ensure that food does not become vulnerable to harmful bacteria. Staff should, therefore, be given specific training on the Cook-Chill operation, in addition to basic Food Hygiene training. Williams Refrigeration and its dealers are able to help you with this.