Extension of food safety regulations from 1 January next year requires all caterers to store food at the correct temperature and maintain HACCP (Hazard Analysis Critical Control Point) logs. Contrary to initial expectations, blast chillers are not part of the new requirements, but environmental health officers increasingly look for evidence of rapid-chilling capabilities in any kitchen that regularly needs to cool batches of cooked food. Chilling down hot food in an ordinary fridge or coldroom increases the proliferation of harmful bacteria and also encourages ice crystal formation, which adversely affects food quality and texture.
Additionally, latent heat in the food can adversely affect the other foods in storage as well as the efficient operation of cabinets and coldrooms. Various methods exist for dedicated fast chilling, from dunking wrapped foods in chilled water to liquid nitrogen, but the simplest and most widely used catering answer is a dedicated blast-chilling cabinet. Helped by a beefed-up refrigeration unit, large fan and special timer controls, these cabinets are designed to take batches of hot food from just-cooked temperature to about 3C in less than 90 minutes.
However, the standard full-size blast chillers used widely in cook-chill and banqueting applications have footprints as big as bakery ovens and five-figure price tags to match. Refrigeration manufacturers supplying restaurants, cafs and pubs recognise the need for much smaller and more economical blast chillers.
For example, the Biostore Turbo SR2 made by Bonnet can chill 8kg batches on its two gastronorm 1/1 shelves for an outlay of just over 2,000, while Universal Foodservice Equipment includes a table-top "baby" blast chiller for about 1,500 in the Italian-made Baron range. Delfield Sadia, part of Enodis UK, introduced a 7kg table-top model, the RS10TO3, this year. The 2,100 list price also includes a shock freezer facility which enables users to go beyond chilling if required and reduce the temperature of hot foods down to a frozen state of -18C within four hours.
With space-saving in mind, the idea of linking blast chillers with other equipment is also attracting interest. Angelo Po now offers a six-grid blast chiller underneath one of its six-grid combi-steamers, which helps reduce manual handling when transferring food as well as optimising kitchen space. Integration between cooking and blast chilling is also practised by Electrolux. Its Air-O-Chill blast chilling cabinets are fully compatible in dimensional and handling terms with its Air-O-Steam combi-ovens.
As yet, it has not proved practicable to incorporate a blast chill compartment inside an ordinary fridge in a way analogous with the fast freeze compartments seen on some chest freezers. But Adande, which makes the innovative VariCool dual-duty refrigerator/freezer counter, this year added the capability of blast chilling in up to two of the VariCool's four removable storage drawers.
"The key issue with standard refrigerators is not the cooling but getting the hot air out," comments David Holliday, Adande sales and marketing director. "Our cabinet was designed from the start with very strong air inflow and outflow, so it was a matter of putting on a booster rather than having to reinvent the wheel."
He concedes that there's an element of compromise. The blast chiller version of the VariCool doesn't have automatic timing, requiring manual temperature probing of food during chilling, while users need to develop a way of juggling their storage whenever they want to use part of the cabinet for rapid chill-down. "But a lot of restaurants we've talked to say that they only need bulk chilling on a Thursday or Friday, so they're not keen to spend a lot of money on a separate piece of equipment," Holliday adds. The cost is an extra 500 on the standard VariCool cabinet price.
For smaller kitchens, cabinet utilisation is an important consideration. The Rose and Crown Inn in Snettisham, Norfolk, serves up to 160 covers on busy weekend evenings in the summer, and proprietor Anthony Goodrich has discovered several uses for the 21kg capacity Foster blast chiller he bought a year ago. Its basic job is to deal with dishes such as lasagne, shepherd's pie and chilli con carne, which are cooked in bulk on a Thursday night or Friday morning and chilled down to be ready for service over the weekend.
"The main issue is to bring cooked food down to refrigeration temperature very quickly, making it much safer," Goodrich observes. "It also saves space in that we can put the food into storage more quickly." The blast chiller also helps the pastry chef on dishes that need to be set quickly, such as recipes containing gelatine, and is useful for holding ice-creams and sorbets for short periods immediately before service. "And we often pop in wines and Champagne to get them really cold very quickly," Goodrich says.
At Byfords, a 200-seater deli, coffee shop and wine bar at Holt in Norfolk, proprietor Iain Wilson is extending the use of the Williams blast chiller he bought three years ago to produce cook-at-home versions of restaurant meals. It was introduced into the preparation kitchen to ensure minimal bacterial growth and, according to head chef Darrell Bethell, has made it possible to increase batch sizes safely with more flexibility in food production scheduling. "Not having to wait long periods for food to cool not only improves safety but allows us to work much more quickly," he comments."
As with a growing number of small blast chillers now available, the cabinet at Byfords is a dual model which can not only chill but also freeze food down to -18°Cif required for longer-term storage. The cost of this extra versatility is modest, at just over 100 on the price of a standard blast chiller.
The cabinet can also be set to hard or soft chilling, another refinement worth considering. Set on hard chill, the chilling temperature drops below freezing to deal with large, dense products such as mashed potato and joints, or foods with a high fat content. The soft chill setting keeps air temperature above freezing and is better suited to more delicate items such as fish, rice and desserts.
Some blast chiller manufacturers have refined such facilities, as with the intelligent food recognition facility on Angelo Po blast chillers, which automatically adjusts chill temperature to prevent surface freezing. And with maximum hygiene in mind, blast chiller specialist Irinox offers a patented sterilisation system which injects ultra-violet (UV) rays into the cabinet to sanitise internal surfaces and prevent formation of moulds or odours.