Commercial kitchens have a vast array of different pieces of equipment designed to aid commercial cookery in an efficient and safe method, the most common – other than that of the oven – would be the Microwave. But how exactly does it work?
Firstly, let’s define a Microwave. A microwave oven is generally a sealed box or chamber with a fan for ventilation and a source of microwave radiation. When food is placed in the chamber and is bombarded with microwave radiation, this ‘excites’ water molecules in the food, which become hot, generating steam and heating the foodstuff around it. This process is similarly described to that of Steaming.
Microwave radiation penetrates deeper into food than heat (infra-red) energy does, and instead cooks from the inside out.
If, for example, a block of butter is placed in a microwave oven for a short time, heat builds up in the centre and so the centre melts before the outside.
Heat can easily build up inside foodstuffs and is not able to easily escape. This can cause burning or other undesirable effects. Therefore, it is important to follow manufacturer’s instructions and test cooking processes carefully.
As microwave ovens use penetrating radiation to cook foodstuffs, there are some products that cannot be placed inside the microwave oven without causing damage to the equipment. There are many materials that should not be placed into microwave ovens. However, most glass, ceramic, and some plastic containers are suitable. Melamine crockery should never be microwaved, as it may catch alight and may cause fire.
Microwave cookery, as a process, involves the transfer of energy to the food in the form of electromagnetic radiation, also known as “Mircowaves.” These “microwaves” or radiation penetrate the food and rapidly move the molecules of liquid it contains. Creating friction, this in turn translates into energy and heat, therefore cooking the food through friction.
Microwaves are designed so that the radiation can bounce around inside and penetrate the food from all angles. “Microwaves” of radiation can move through some types of containers, as it is only when the waves reach the water molecules in the food that friction is created. This is also why some materials, such as metals, are unsuitable for microwave cooking, as the radiation will come into contact with the metal and cause unecessary friction.
Microwave ovens are convenient and useful appliances, but they do have some limitations due to the nature of this cooking process. Microwave ovens do not tend to produce the same results as conventional cooking methods. For example, microwaving foods does not produce the same browning effect that grilling or frying does. This is because microwaves do not use applied heat to cook foods, but rather that of friction, meaning – food can be cooked without coming into contact with any heat source. Pastries and cakes tend to go soggy in a microwave oven because of the steam created by microwaving, as baked goods and pastries can have high water content. The friction caused by the “microwaves” can therefore bring out the liquid and disrupt the chemical balance of the food. In general, microwave ovens are smaller and have limited capacity compared to a standard oven – therefore limiting the types of food that can be cooked in microwave ovens, and also the quantities in regard to cooking commercially.
However, microwave ovens can also be advantageous in a commercial kitchen, as they are particularly useful for:
- Defrosting frozen foods,
- Reheating pre-prepared dishes,
- Cooking foods that don’t require browning,
- Foods that can be cooked fast at an even temperature.