The micro climate
THE speed and convenience of microwave ovens have ensured a place for them in most kitchens performing a great number of specialist tasks. But as their applications grow, it is important to choose a model whose performance matches the needs of the job.
So what should you look for? The Association of Catering Equipment Manufacturers and Importers (CESA) warns against being fooled by exteriors. A domestic microwave oven may look very much like its commercial big brother, but it is not designed for the same consistent use - it doesn't have sufficient facility to cool the magnetron component (the source of the microwave energy), and if a microwave's components overheat through extended use, the cooking power may drop, resulting in undercooked food.
Getting the power right is also important. CESA recommends that when you need things done quickly you should remember that a 2kW model can cope with nearly double the throughput of a 1kW model. All commercial models in the medium to high category (more than 1.4kW) will have two magnetrons, and some of the larger ones as many as four. Below 1kW they will have only one.
Although magnetrons are the source of microwave energy, extra magnetrons do not necessarily mean better speed or power: they are simply a way of designing the appliance so the energy is balanced. Over time, or with heavy use, the power of a magnetron will decline.
Size also needs to be considered. Larger models will take two full-sized plates side by side or a 1/1 gastronorm container, and some have a central shelf to double capacity. However, the bigger the load, the longer the heating time, so for single portions a smaller model will do the job more economically.
Having different power levels is a useful option, as reducing the power can be important in delicate work. Programmed power levels make it easy to alternate between a full oven, half-full and defrost, for example.
Get the timing right, as well. While simple dials may suit some, more and more manufacturers are introducing keypads, which can hold predetermined cooking times in the oven's memory and some will work out the times for multiple quantities. Preset timings are useful if you regularly cook or heat the same products and they are invaluable in vending applications.
Make sure the oven is easy to clean and made of rust-free stainless steel, as paint finishes can chip and are not sufficiently hard-wearing for commercial use. Having rounded corners inside avoids dirt traps. Also, look for an effective door-locking system to minimise the risk of leakage. This can occur if the oven has been badly knocked or dropped, or if the door and its seals are damaged. If this happens, the oven should not be used until it has been professionally checked.
Manufacturers meeting needs
So how do manufacturers respond to these ideals? Samsung, which claims to be the world's largest manufacturer of domestic microwave ovens, introduced two commercial oven ranges for the first time last year. There are two models in each range, one with manual controls, the other with a touch-pad and 30 programs.
Power outputs of up to 1.4kW are available in the medium-duty range, while the heavy-duty version goes up to 1.8kW. They all have twin magnetrons, using a system that distributes microwave power throughout the oven in a uniform heating pattern, creating less spitting and splashing, says the company. Made of stainless steel and with an oven capacity of 26 litres, the company claims that the ovens are one-third larger than the nearest competitor, despite having a footprint of just 240mm x 240mm. A special feature of the ovens is the "zap-pad", which enables users to add 20 seconds to the cooking time without stopping the program.
Automatic programs
Zanussi's ZA1200 model has a double-quantity pad that automatically increases the programmed time for two servings, and an option to automatically repeat the previous cycle even when it is manually selected. Oven capacity is 20 litres and it has a 1.2kW power level. Its strong, stainless steel construction means that two ovens can be stacked.
Hobart's new HDM1700 (1.7kW) takes up just 425mm x 600mm of counter space and offers a choice of settings from 0-100% in 10% increments. Four quick-power buttons allow 100%, 50%, 25% and defrost to be instantly accessed, saving valuable time in busy periods, says Hobart. Another time-saving feature allows the oven to be programmed to take a product from frozen to fully cooked by pressing one button.
Once cooking times have been determined, the 10 most popular items can be programmed into the oven's memory. Other new features include the X2 and X3 cooking operation, which means that once the time has been set for one item, by touching X2 you can cook two portions, or three with X3.
Claiming to offer the widest range of commercial microwave ovens in Europe, Merrychef has a wide variety of styles and functions available. The Microcook range includes six models between 1.025kW and 2.025kW with full gastronorm and 500mm standard cavities. The Mealstream combination oven is available in two models: the Series 5, which features multi-stage electronic microprocessor control with manual, rotating dials; and the Microaire range of mid-size ovens.
The Mealstream compact medium-duty combination oven is powered by 550W of microwave and 2kW of hot air and is fitted with one magnetron. It is claimed to have the capacity to prime-cook dishes in one-fifth of the time of a conventional oven.
Another combination microwave oven is marketed by Lincat: the MW3, a compact microwave with conventional oven, fan-assisted oven, conventional grill and fan-assisted grill all in one.
"Each of the four cooking options can be used singly and the microwave function can be used with each of the other cooking methods, such as microwave with oven or microwave with grill," says marketing manager Nick McDonald. "This makes it easy to give a crisp, brown finish to meat or poultry while retaining the speed of microwave cooking."
It is made from stainless steel with vitreous enamelled interior, base and top panels and a self-clean back panel. The fan-assisted operation allows for fast heat-up times and baking on two levels. n
