Combi power
Chefs call them combi-ovens because they see them as convection ovens with lots of extra functions - such as steam injection, which can deliver much better quality food than dry convection ovens. Manufacturers prefer to call them combi-steamers because they don't want their cooking machines pigeonholed as standard convection ovens but with a few more bells and whistles.
Whatever name is given to them, there is no doubt that over the past 25 years the development of this piece of prime cooking equipment has changed the way professional kitchens operate.
Combi-ovens have traditionally been used for big food operations - hotels with banqueting needs and large numbers of residential guests, hospitals, universities and cook-chill production systems. That has changed as combi-oven manufacturers have begun to produce combi-ovens that are more versatile and more suited to the smaller end of the market.
The high-capacity market is still important, but manufacturers have recently been taking steps to produce ovens for catering operations that have previously considered a combi-oven either unnecessary or not financially viable.
Lincat is one of many combi-oven manufacturers that are giving first-time users and smaller kitchens as much attention as big production kitchens.
Nick McDonald, marketing and export director at Lincat, says it is wrong to assume a chef needs a big food operation to make a combi-oven viable. He argues that the wide range of cooking functions in a combi-oven can make many other items of prime cooking equipment redundant in a smaller kitchen, so it makes sense for small to medium-sized businesses to buy one.
Although even an entry-level combi-oven can be an expensive investment for a small kitchen, McDonald says chefs should not opt for the cheapest available. "Go for the best you can afford," he says. "A good-quality combi, properly maintained, will last many years. Taken over the whole working life of the combi, purchase price differences between models are relatively inconsequential."
Pub economics Food-driven pubs are typical converts to the combi-oven. Ray Scarbrow, owner of the Live and Let Live pub in Pegsdon, a village outside the Hertfordshire town of Hitchin, believes any pub with a busy restaurant business should have a combi-oven as a core part of its prime cooking equipment.
"When I bought the Live and Let Live a year ago it was run down and had been closed for a year," he says. "I started from scratch with the kitchen, chucking out all the old equipment.
"My local equipment distributor said I should install a combi-oven as an essential part of the new food operation. I went into the showroom expecting to pick to pieces his argument for a combi-oven in a small pub, but after half an hour I was convinced a food-driven free house like mine could see a business benefit from a combi."
While frozen and convenience food play a part in the pub's menu, Scarbrow wanted the emphasis on fresh food, particularly freshly cooked meat. He soon recognised the profitability of using a combi-oven for roast meats rather than a conventional oven beneath a cooking range.
The Live and Let Live has a broad-ranging menu but has become noted for its daily roast meat offer. This has helped the pub build up business from nothing to 500 main-course meals a week. The food-to-wet sales mix is now 70:30 and evening spend averages £20 a head.
The combi-oven used at the Live and Let Live is a six-grid CPC-61 ClimaPlus Combi from Rational, which, while delivering the daily roasts of meat with minimal weight loss, is also used for baking pastry desserts and regenerating pre-cooked vegetables.
"The combi-oven is absolutely brilliant for cooking joints of meat," Scarbrow says. "We do ribs of beef, a daily turkey, legs of lamb, whole hams - anything we put in comes out consistent. Pegsdon might be only a tiny village, but we have become a destination food pub within a year of opening."
Another pub to benefit from the combi route is the Seagull Inn at Brean in Somerset, between Weston-Super-Mare and Burnham-On-Sea. But this is a bigger operation than the Live and Let Live. It is a 700-seat restaurant and cabaret venue as well as a pub and can serve 1,000 carvery meals a day in high season.
Despite the volumes, the kitchen had stuck with conventional dry-roasting and vegetable cooking on an eight-burner gas range. But even when it became obvious that this traditional cooking method was struggling to deliver, there were still doubts that combi-ovens would provide a better product and greater efficiency.
Persuaded to go down the combi-oven route, the Seagull Inn bought two Angelo Po 40-grid Steam combi-ovens to cook the 30 joints of meat needed at peak service times. As with all who use a combi-oven for the first time for roasting meat, Seagull Inn head chef Dave King found that meat shrinkage caused through dry-roasting was hugely reduced and that meat tenderness through the steam injection in the combi-ovens was hugely improved.
Buying an oven
Combi-ovens may bring benefits for all, but buying one is not as straightforward as buying, say, a microwave or food processor. First, a small kitchen should be measured up before a combi-oven is bought, says Neil Roseweir, development chef for Falcon Catering Equipment. A business should ask itself some basic questions: Can a combi-oven fit through the kitchen door? Are power resources available? Is there adequate water supply, ventilation and water drainage?
Roseweir also has words of warning about missing out on the business benefits of combi-ovens, particularly at functions such as weddings and smaller banquets.
"Smaller urban or rural hotels usually have a strong business in smaller functions and the temptation is to use conventional cook-serve or to try and regenerate in a dry oven. It can work, but the chances are the food that arrives on the plate will either be cool, dried or a mixture of both.
"Just because the numbers at a function are not high doesn't mean that customer expectation is not high. Smaller hotels should invest in providing the same quality of equipment as big hotels."
Steve Loughton, managing director of Enodis Distribution, says first-time buyers should not be frightened off by the big brands of combi-oven associated with high-volume production.
His company sells Convotherm combi-ovens, designed to withstand heavy use, but he says: "They are equally at home in small kitchens. While a big production kitchen may restrict the role of the combi to a few clearly defined functions, such as roasting, cooking vegetables and cook-chill regeneration, for a smaller kitchen there is so much versatility in the combi-oven that it opens a new dimension in how much of the overall cooking process the oven can do."
Scott Williams, head chef at recently opened Kilworth House country house hotel in Leicestershire, goes a step further. He describes the new Zanussi Active combi-oven he bought from Northamptonshire equipment distributor Whitco as "a big step forward in food safety" .
The Active range measures and records food-cooking temperatures via a six-point sensing probe inserted in food during cooking. Williams says this will be a very welcome HACCP (Hazard Analysis, Critical Control Points) food-safety tool for events such as banquets, where large quantities of food are being prepared.
To operate the monitoring system, the oven is switched into Foodsafe mode and the probe inserted into the food for automatic monitoring of the cooking process. A red light on the control panel will switch to a green light only when the probe is satisfied that the food is microbiologically safe.
For Williams, just returned from eight years cooking in the Caribbean, another benefit of the two Zanussi Active combis he has as part of his kitchen is their even cooking performance at low temperatures.
"Any combi can work at high heat but low temperature can be a problem," he says. "These oven are very even when cooking things such as mousses and parfaits."
Lack of awareness
Many small kitchens simply do not recognise the scope of cooking options offered by combi-ovens. Robin McKnight of Dawson Foodservice Equipment, UK distributor of Lainox combi-ovens, says: "When a kitchen has big production needs chefs look at combi-ovens as a first-line item of cooking equipment.
"A chef who has been trained in a big kitchen, and who knows how versatile a combi-oven is, might move to a smaller kitchen and suggest to management that a combi-oven would produce better food and be more cost-efficient But a common reaction is that combis are only for the big guys.
"It's frustrating for a chef who knows how versatile a combi is and how suitable one is for any size of operation to be told that a four-burner oven range is all that's needed."
Another non-traditional area in which combi-ovens are increasingly being used is in schools. Allyson Lloyd, catering contract manager for schools in the south London borough, claims the quality and efficiency of lunchtime feeding in Croydon significantly improved last year when combi-ovens were introduced.
As part of a major sweep through the borough's food-preparation system, she decided to use combi-ovens from Rational and claims they have been versatile, space-saving, energy-saving and reliable.
St Mary's Junior School in Croydon is a good example of the way combi-ovens have become a focal point for school kitchens in the borough. St Mary's kitchen caters not just for its own 200 children but also for another local school.
What is a combi-oven? According to the Catering Equipment Suppliers Association (CESA), a combi-oven combines several cooking functions in one piece of kitchen equipment. It is by shortening the description "combination" that the combi-oven has got its name. An alternative name for the oven is the combi-steamer. The combi-oven uses dry heat - either still or fan-driven - and steam, which is injected into the oven as necessary. It is a versatile piece of equipment that offers the following cooking benefits:
* Meat - Up to a third of the weight of a piece of meat can be lost during dry roasting through loss of the water content of the meat. Having gentle steam in the oven during roasting both minimises weight loss and produces a more tender joint.
* Fish - Steaming is an ideal cooking medium for this delicate protein.
* Vegetables - By cooking in steam instead of boiling water, vegetables keep more of their nutritional value.
* Baking - By operating as a fan-driven convection oven, baked goods are evenly and crisply cooked. A slight injection of steam can also enhance baked foods such as bread.
* Regeneration - Food that has been pre-cooked and correctly chilled prior to service can be rapidly brought up to serving temperature, avoiding the need to hold food hot for long periods, which leads to flavour loss and drying out. Combi-ovens are ideal for busy banqueting operations and can handle both ready-plated meals and multi-portion containers.
Baking solution
One of the newest brands of combi-oven into the UK is HansDampf, distributed by MKN. Although a new name in the UK, this German-built combi-oven range is a leading brand in mainland Europe and there are smaller models that offer much of the versatility small kitchens look for.
MKN business development manager Paul Searing says the company's six-grid electric combi can perform many of the cooking functions small to medium kitchens require. Its bread-baking cycle offers the following sequence of functions:
* Proving at low temperature, with a puff of steam to prevent crusting
* A rest period
* High baking with steam to form a good crust.
* Before the end of the baking cycle, all steam is exhaled to provide a dry final baking period for a golden, crisp crust.
Searing says that while the outright purchase cost of a combi-oven is daunting for a smaller caterer, lease deals are available from distributors, often with the option to buy at a low price at the end of the lease period.
Limescale alert
Failure to fit a combi-oven with a water filtration system to remove limescale will lead to higher energy costs and very costly repair bills when the internal water pipework becomes furred up.
It is only ever safe not to fit an individual filtration system to a combi-oven if the general supply to the kitchen or the hotel goes through a centralised filtration system before it is distributed around the premises.
In a combi-oven, the most likely point for limescale is in the feeder pipe that generates steam or, if the combi has an internal steam boiler, within the boiler.
Research by water treatment company Brita shows that 70% of breakdowns in water-fed kitchen equipment can be attributed to hard-water limescale. It also claims a 4mm build-up of limescale on heating elements results in a 25% reduction in energy efficiency.
Microwave power
While traditional combi-ovens rely on a mixture of convection and steam to perform the cooking functions, Leventi combi-ovens, which are now distributed in the UK by Valera, include a third cooking medium - microwave power. Using a method of combining controlled microwave energy with steam and convection, the Leventi can reduce cooking times by up to 50%.
With the addition of microwave, the five-grid model will cook 20 1kg chickens in 12 minutes or 70 jacket potatoes in 22 minutes, while still retaining moisture, texture and flavour in the same way as a normal combination oven. Despite the use of microwave energy, the Leventi combi-ovens can still take metal pans. They are available in three-grid and five-grid configurations, which makes them an option for first-time buyers.
Suppliers
For more information on combi-ovens contact the following:
Angelo Po 01332 638030
Bonnet 01494 464470
Convotherm 020 8561 0433
Falcon 01324 554221
Hobart 07002 101101
Lainox (Dawson MMP) 01226 350450
Lincat 01522 875555
MKN 01709 380567
Rational 0800 389 2944
Servequip 020 8686 8855
The Catering Equipment Suppliers Association 020 7233 7724
Valera 01708 869593
Whitco 01832 735007
Zanussi 0121-220 2844
