Serveries: Self-service hots up

18 April 2007
Serveries: Self-service hots up

The sale of freshly cooked food via open-front shelves is spreading from sandwich bars and convenience stores to coffee shops, staff restaurants and hotels. Bruce Whitehall asks how designers are tackling the challenges of maintaining safe, consistent temperature and humidity

The ever-shortening lunchbreak taken by UK office workers and shoppers - less than 28 minutes, according to the Eurest Lunchtime Report 2006 - has undoubtedly contributed to the hot food-to-go revolution promoted by the likes of Marks & Spencer and Pret A Manger. The latter traditionally focused its food offer on cold sandwiches, salads and desserts self-served from retail-style chilled shelves. But in the past year it has introduced a choice of hot wraps, cooked fresh in the kitchens at each unit and presented in specially developed paper packs, at all 150 of its UK sandwich bars.

With the tight dimensions of each store, open-front heated shelf units had to fit seamlessly within the existing chilled display shelves so that customers could grab both hot and cold items without delay or complications at the service counter.

The solution proved to be Grab & Go merchandising units made by Dutch company Fri-Jado. Just 620mm wide, each full-height cabinet keeps hot products stable and palatable in a circulating air-flow current that also enables customers to touch the shelves without burning themselves. Pre-programmable controls maintain the required air curtain temperature without the obstruction of doors or plastic insulating strips.

The Nuttall Group has also tackled the challenge of open-shelved hot foods with its Turbo-Serve cabinets, initially developed for Marks & Spencer and now seen in various outlets prone to sudden influxes of customers, such as schools, colleges, sandwich bars and petrol station forecourts. Heat generated in the cabinet base circulates over and around the open-fronted grille-type shelves.

Marketing manager Alison Nuttall says it took nearly four years to resolve the conflict between consistent product quality and maximum customer accessibility. The biggest challenge came from draughty locations, especially near air-conditioning units. "It is possible to adjust the temperature of the air supply within the unit but what you don't want is an extremely high temperature because that will dry products out," she says. The happy medium is usually a core temperature around 68-72°C, which generally needs the heat unit in the cabinet base to run at 82-84°C.

Equally significant is the design of the food packaging. This led Nuttall to ally itself with a company called Cafe Connection as packaging partner. "People eat with their eyes and they really want to be able to see the product so clear packaging is important - but it must also not mist over," Nuttall points out. "For that you need small ventilation holes of exactly the right size too big and the product dries out too small and products such as pastry go soft."


Ian Osborne, group managing director of Enodis UK, sees the new generation of open-front grab-and-go shelf units as a major development in the fast-food sector. "Previously the pressure has been on the outlet staff to remove the hot food," he says. "Now the customers can do it themselves, saving valuable time for the clients and staff. In most cases these units are in convenience locations where the consumer wants to be in and out in less than two minutes."

Open-front merchandisers under Enodis UK's Delfield Sadia brand are made in 900mm and 1,300mm widths with three glass shelves per section, profiled glass sides and rear access via hinged doors. All modules - hot, cold or ambient - are visually identical when put together to give a clean appearance in both retail and food service applications.

Anti-fog technology

In applications where putting hot food behind glass is better than packaged grab-and-go, the attractions of visibility can be impaired if food dries out or if the glass panels or sneeze screens steam up. Simon Lopeman, commercial manager at ServEquip, claims that patented ThermaVec technology, which his company employs on its Henny Penny humidified heating cabinets (made in five sizes and four profiles), can resolve such issues, preventing both fogging-up and hot or cold spots.

Special sensors operate in conjunction with the heating elements to detect and compensate for changes in air temperature and the humidity created by water wells. The technology can also help towards an issue experienced with all hot food display: how to maintain the condition of different foods consistently within the same cabinet. This is achieved by "zoning" elements and can enable a mixture of foods such as rice, bhajis, naan breads and curries to be displayed alongside each other. "Using just one piece of kit is not only a vital space saver and efficient but is a real cost saver for caterers," Lopeman says.

Another hot food display/serving concept suited to fast on-counter service is the Hatco Flav-R-Savor range of heated and humidified display cabinets which offer the ability to hold hot savoury and sweet products such as pizza in a controlled, moisturised blanket of heat. Units can also be used, if necessary, to bring frozen bread products up to serving temperature, easing pressures on cramped or busy kitchens.

Hatco is also active in more conventional hot-food display applications involving serve-over counters. Finding that the impact of open display was often diluted by heat-lamp gantries, the company identified a need for a bigger choice of cloche-style heat-lamps in keeping with modern serveries and without the industrial look of many standard lamps. The resultant Decorative range comprises eight mix-and-match lampshade styles with any of eight mounting options, four switch locations and 12 colours and finishes - from warm red and hunter green to brass and nickel. Lamps are available in high wattage versions for overhead food warming and standard versions suitable for lighting only.

Cooking and display trolleys

Another new approach to hot-food presentation is the mobile cooking/display counter unit with a choice of hot, chilled and ambient tops and built-in lighting. In units such as the Rieber Varithek, one important option is built-in air extraction. Cooking smoke and fumes around the sides of the top are pulled through fan units and carbon filters within trolley bases, eliminating the cost and complications of fixed overhead extraction.

Extending the principle of multi-functional trolleys one stage further is E&R Moffat. Its Chillogen line of trolleys, which have built-in facilities for chilling, storing and heating, either sequentially or as discrete functions. While mainly intended for applications such as function catering and hospital ward meal service, the trolleys can effectively act as kitchen extensions during busy periods or whenever space is at a premium.

Safety issues

Delivering food of consistent quality which does not dry out is the main aim with all heated display cabinets and trolleys but caterers need also to be aware of the tighter food safety regulations that came into force as part of EU safety laws (EC 852) from January last year. These require caterers to make formal records of food holding times and temperatures. Failure to comply leaves caterers open to fines of up to £20,000 or a prison sentence.

The new laws encouraged Lincat to rethink its Seal display cabinets, made in hot, cold and ambient versions. Heated food display merchandisers, for example, are now built to hold food at a minimum of 72°C - well in excess of current safety requirements - with built-in humidity controls to guard against drying out. The parallel ranges of chilled food display cases and counters are now designed for holding food at 3-7°C and 60% relative humidity.

The Turbo-Serve cabinets (below) from the Nuttall Group use circulated hot air to keep food at the right temperature. Right: Lincat's Seal cabinets


BGL Rieber - 01225 704470

Delfield Sadia/Enodis UK - 0845 370 4888

E&R Moffat - 01324 812272

Fri-Jado/Equip Line - 01895 272236

Hatco - 01664 424323

Henny Penny/ServEquip - 0845 390 9808

Lincat - 01522 875500

Nuttall Group - 01455 638300

Key maintenance points

  • Regularly check the trolley temperature read-out against your hand-held reader. If it's not the same (or almost the same), don't use the trolley again until a service engineer has checked the heating and calibration.
  • When it's hot in the summer, leave the display case operating temperature at normal - don't turn it down. It will ice up the evaporator, and cause it to go over temperature.
  • Refrigerated servery counters may not be designed for storing food overnight. After service, move the chilled products to overnight storage and switch the servery off, so it can defrost.
  • Use only food-approved lamps in your heated display counter. Keep a spare one handy so you can get it replaced quickly when you need to.
  • Open-front display cases may struggle to maintain temperature if the curtains are not pulled down between service and overnight.
  • Most trolleys have bumpers, but these are to protect them (and your premises) from damage, and not to encourage rough handling. Most damage to trolleys results from careless use such as crashing the castors over rough ground, and bashing into walls.
  • Remember to release the brakes before towing otherwise the castors will flatten on one side. Damaged castors are a safety hazard, so must be replaced as soon as possible.
  • If you see damage to the cable on a heated or refrigerated trolley, don't plug it in - have an electrician check the cable and gland.

Source: Serviceline 01438 363000

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