Technology has provided commercial kitchens with an array of equipment for applying heat to food, from combi ovens and digital water baths to induction hobs, but one method of cooking has enduring appeal for diners all over the world - grilling over hot coals.
High above street level in London's Kensington High Street, Babylon restaurant at the Roof Gardens takes full advantage of the UK's love of barbecues.
"Barbecues are popular in the UK as a lot of people tend to associate them with big social and family events, with good food and drink, in the summer months," says deputy restaurant manager Peter Avis.
"The whole concept creates a relaxed and fun environment, and our guests really enjoy being able to watch the chefs in action as they cook on the barbecue."
Seven tables are set out in the gardens and the area is covered by a canopy, with heaters available if the weather turns chilly. The barbecue menu is available from May to September and includes tiger prawns, Scotch rib eye steak, spatchcock poussin marinated in garlic and smoked paprika, pork and apple sausage, lamb thyme burger and vegetable skewers with halloumi cheese, all cooked on a gas-fired barbecue grill.
Barbecues are a popular summer attraction at about half of the 2,300 Scottish & Newcastle pubs around the UK where they use Outback Pro gas barbecue grills with four or six burners. As manager of the British Barbecue Team and the 2004 winner of the National BBQ Association's Britain's Best Barbecuer award, the group's food development manager Ben Bartlett is something of a barbecue guru.
"Pubs with beer gardens are really geared up for barbecues and the informality appeals to all ages," he says.
"People enjoy the creativity of a professional chef cooking on a barbecue, for instance, trout stuffed with thyme and wrapped in vine leaves, or desserts with chunky fruit such as pineapple."
Starting next month, Bartlett will run an alfresco roadshow for the estate's tenants, where they can learn about suitable cuts of meat for barbecuing and get involved in interactive cooking demonstrations.
According to Ray Hall of catering equipment supplier RH Hall, in light of the smoking ban and the recession it has never been so important for operators to use any outdoor space they may have.
"It's probably down to our unreliable climate, but many food service operators fail to maximise on the profitable opportunities offered by barbecues and other alfresco dining occasions," he says.
"With a little imagination, any establishment can easily turn outside areas into an extension of their business, adding valuable seating space and generating an opportunity to grow turnover through additional food and beverage sales."
RH Hall supplies the stainless steel Smeg BQ91C professional barbeque, which provides a large 700 x 420mm grill area with three powerful 5kW gas double burners, six enamel cooking grids, an internal water reservoir drawer and a drip tray that prevents flare-ups and aids cleaning. The stainless steel base has two cupboard doors and lockable wheels.
Hall says: "Professional barbecues feature high pressure burners, which are unaffected by wind, and castors or legs that resist sinking into soft earth. The power to cook efficiently and quickly is vital - a single grill area on a professional barbecue will turn out, for example, 16 well done 8oz steaks in just eight minutes."
Perhaps one of the best known makes of commercial barbecue is Cinders, as supplied by 3663. The Caterer TG160 and Cavalier SG80 have high-pressure burners, which are unaffected by the wind and reach cooking heat in less than five minutes. A self-cleaning feature that works by reflected heat is incorporated into both pieces of equipment, meaning there is no need to dismantle the barbecue to clean it, and excess fat can be collected in a disposable ring pull can, making it easy to dispose of after use.
The foldable legs are designed so they don't sink into soft ground, and once folded up, they protect the controls so the barbecue can easily be stored upright on its end. Total grill areas are 7,312sq cm for the Caterer TG160 and 3,656sq cm for the Cavalier SG80.
CHOOSING THE RIGHT KIT
Keith Warren, director of the Catering Equipment Suppliers Association (CESA), offers advice on choosing the right kit for the job.
"Ideally a commercial barbecue needs to deliver a controllable heat source so that food can be cooked safely," he explains.
"Gas is ideal for this because it offers flexibility and reliability. While there are plenty of barbecues around, buyers need to be careful - quite a few don't carry the CE mark. A CE mark indicates that a product has met EU safety requirements. It's a mandatory requirement on catering equipment sold in the EU so if it doesn't have the CE mark, it's not legal for you to use."
Even if the cooking isn't taking place outdoors in a traditional barbecue setting, many restaurants recreate the outdoor barbecue experience using an under-fired open-hearth charbroiler or chargrill.
Warren explains: "This is basically a firebox with a top grate of cast iron or steel on which to broil food. The top grate becomes very hot and is designed to add sear marks to the food - the charbroiler's trademark signature."
Neil Roseweir, development chef for Falcon Foodservice Equipment, explains the science behind chargrilling.
"Chargrilling is cooking over an open flame and is a relatively quick cooking method. The unique flavour is due to the two different types of heat transfer - the food resting on the bars is cooked by conduction and the food between each bar by radiation," he says.
Roseweir considers it a great way to cook food but warns operators of potential pitfalls.
"The cuts of meat need to be tender, such as fillet and sirloin, as this is not slow cooking and only certain cuts can cope with the temperature, which reaches 330e_SDgrC. You really need to understand the heat and when to turn, season and oil, or the food is easily overcooked."
While lava rock is the most common way of delivering the heat on a chargrill, a drawback is that it can become impregnated with food, which creates smoke when it burns off and makes for difficult cleaning. Consequently some manufacturers have done away with the need for lava rock.
Falcon's radiant chargrills do not require any coals and feature double-sided brander bars that can be turned during busy periods, with channels to direct grease flow and angled to reduce flaring and smoke within the kitchen. The company supplies chargrills to Whitbread's Beefeater restaurants, which champion this method of cooking.
Suzanne Curry, head of marketing for Whitbread restaurants, explains: "Chargrilling gives customers an experience with their food that they cannot easily recreate at home. It works by cooking food over an intense heat to sear in all the flavour and juices while giving the food an irresistible smoky crust with the chargrill branding bars."
Beefeater launched its spring/summer menu in February, offering traditional chargrill dishes with different seasonal dishes every six weeks. Choices include a giant chicken skewer, topped with bacon and bourbon and black barbecue sauce, and Beefeater's signature ribs with new sauces such as sticky tomato and chilli, and spiced Worcestershire.
Lincat has replaced the lava rock with heat transfer radiants in its Opus 700 and Silverlink 600 chargrills.
"It is the igniting of fat and flaring that gives food a chargrilled taste rather than the lava rock itself, which gives off no aroma," says Paul Hickman, Lincat development chef.
"The heat transfer radiants are more controllable and consistent than lava rock, yet still ignite sufficient fat for optimum flaring to give a distinctive chargrilled taste. At the same time removable branding grids provide the characteristic branding effect. These can be removed at the end of the cooking session, together with the radiants, fat collection tray and splashguard to facilitate cleaning."
Aiming to give consistent results each time is Imperial's CrossFire Over-Fired Broiler, available with two or three burners. The 0.5in thick polished steel searing plate with splash guard seals in flavour and moisture, while ceramic radiants direct heat downwards to penetrate the exposed surface of the meat, which protects it from too much hot air and convection, to ensure minimal shrinkage and a tender result.
The adjustable grids are removable for cleaning and have a 3in range to ensure precise broiling. The broiler channels direct built up fat away safely so they don't collect and flare dangerously. Grease from the broiler is disposed of via the removable grease pan while run-off from the extended grids is caught in the large front-mounted trough.
A rather different approach to grilling comes from Black Rock Grill, which offers a hot volcanic rock cooking system for added theatre and customer interaction at the table. Orders are brought to the table sizzling on a hot rock ready for the customer to cook it to their requirements. The Black Rock Grill is available to hire in 30, 60 and 100-rock ovens and there's a Café Rock 16-rock system for smaller operators.
Pub restaurants the Bird Cage in Oxfordshire and the Sausage Tree in Buckinghamshire have seen an increase in food sales since introducing large tables to seat 30 for special Black Rock Grill nights, and in Pembrokeshire, the Carreg Bar, Bistro and Restaurant now uses its courtyard and garden to encourage families to enjoy dining outdoors from the Black Rock Grill.
A similar idea comes from the Red Hot Plancha System, which is about to be trialled in a dozen Scottish & Newcastle pubs. It consists of a round table with a Teflon-coated cooking surface in the centre on which diners seated at the table can cook their food.
3663 Catering Equipment
Black Rock Grill
Falcon Foodservice Equipment
RH Hall (Smeg)