Buying Commercial Microwaves
Microwave ovens are an important part of every professional kitchen. A microwave can perform essential functions such as safely re-heating frozen or chilled food, which is at the heart of many menus in informal dining restaurants, pubs and in room-service for hotels.
How do Microwaves Work?
Microwaves use ‘micro waves’ to heat food at a frequency of 2,500 mega hertz (MHz). When the waves are absorbed by water, fats or sugars, they’re converted directly into atomic motion – or heat. Micro waves are not absorbed by most plastics, glass or ceramics but they are reflected by metal, so never put any metal pans or utensils in a microwave. Unlike conventional ovens where heat is conducted from the outside of the food towards the centre, the microwave’s radio waves ‘excite’ the water and fat molecules evenly throughout the food.
Commercial vs Domestic
There is a minority view among caterers that all microwave ovens are the same, the only difference between commercial ovens and domestic ovens being the power and price. This is in fact false. There are clear cooking, construction and food safety differences between microwave ovens designed for domestic use and those designed for use in a professional kitchen. Microwaves are available in a choice of power levels in either manual or automatic touch pad controls.
Domestic microwave ovens are often low power, which means they will take far longer to reheat, defrost or cook food than a commercial one. While domestic ovens have a power rating from 600 watts to 900 watts, commercial microwaves can be up to 2000 watts. The device which produces the energy waves which heat food in a microwave oven is called a magnetron. Domestic microwave ovens usually have a single magnetron while commercial microwave ovens usually have two magnetrons which are built to a higher specification, making them faster, more efficient and longer lasting.
Commercial microwaves are built to withstand hard use every day, while a domestic is designed to be used a couple of times a day. Microwave energy needs to be evenly spread around the oven cavity to ensure that all parts of the food inside are safely heated. Where chilled or frozen food is not thoroughly heated, harmful bacteria within the food is unlikely to be killed, risking food poisoning. Many domestic microwave ovens use simple turntables to try to distribute the heat, while commercial microwave ovens have sophisticated heat mixing systems in the oven cavity.
The casing of most domestic microwaves is painted mild steel which will chip, corrode and cause food safety hazards. Most commercial microwaves have casings made with hard-wearing stainless steel which is easy to keep clean and will not corrode. Commercial microwaves are likely to have far more sophisticated cooking programmes, often push-button pre-sets, so staff can reheat properly and easily.
Grouping Commercial Microwaves
Manufacturers group commercial microwaves into four power bands:
The oven will have a power ranging between 900 watts and 1100 watts. This is suitable for use where demands are light, such as a café.
A power rating of 1100 to 1500 watts, proportionately more robustly built than a light-duty and suitable for locations where the microwave is only in occasional use.
Powered from 1500 to 1900 watts and the most popular power range used in catering as they are built to withstand heavy use. They are suitable for busy environments.
These are used when large quantities of food are needed to be reheated quickly.
Energy Efficient Microwaves
Kitchens are aware that switching on the six burner for hours is bad on all sorts of fronts; energy, kitchen environment, over working the ventilation, and costs. It’s much better for them to par-cook food items and then regenerate them on demand. Microwaves are perfect for this as they are flexible, so chefs can regenerate fast in either single or multi portions. By cooking or regenerating on demand, kitchens cut down on wastage, too.
Where microwaves get much more versatile is when they become a combination microwave oven, with the addition of convection hot air and a grill. When a microwave is a combination microwave, it turns a simple re-heating cabinet into a multi-function cooking oven. For example, jacket potatoes can be softened then crisped and pastry dishes can be reheated and crisped. A general rule of thumb is that a microwave is only is for re-heating, combination microwave ovens are for reheating and primary cooking.