Frowned on by some cooking purists but nevertheless a handy gadget
Available in free standing and built in options and in a range of sizes, the microwave can be a very useful device. Ideal for a reheat task or for defrosting, but particularly combination microwaves offer scope for more serious cooks.
How do Microwave Ovens work?
The heart of the microwave oven is a device called a magnetron. This produces high frequency electromagnetic waves which penetrate into food and cause mainly water molecules to bounce around. This movement creates heat, so the food is heated from within. The wave energy can tend to concentrate in small points so a stirring rod is employed to scatter the waves around and so prevent hot spots occurring. Many microwave ovens also use a turntable to keep the food revolving and further reduce the occurrence of hot spots. This design ensures that food is heated evenly throughout, preventing overcooking in some spots and undercooking in others.
It is important to allow food to rest for the recommended time after the microwave oven switches off. This is because the molecules will still be moving rapidly and generating heat for a time after the wave energy ceases. Its a bit like pushing a swing, the swing will continue to move for a while after you stop pushing. How long food needs to stand for depends on the food, the quantity, how loong it has cooked for and the power of the microwave oven. Food labels will usually have microwave instructions these days, setting out timings for different microwave powers.
Power levels.
Microwave Oven power output is classified from A (the lowest power) to E (the highest). Power level measured in Watts is most commonly around 650W for a category B, 770W for a category D and 850W for category E. There are some even more powerful models around now, maybe up to 1000W. Simply put the higher the power rating, the faster the oven will cook.
The power level will be shown usually on the door of the microwave oven. Most ovens also have variable power settings for defrosting and gentle cooking.
Limitations of microwave cooking.
Because microwave ovens do not use radiated of conducted heat to cook the appearance of microwave cooked food is very different from regular cooking. Meat in particular will not look well cooked as the surface does not brown or caramelise. There are accessories such ad browning trays and browning bags availoable which will help to make meat in particular look more palatable. Another answer is the Combination Microwave
Metal plates utensils and containers should not be used as the wave energy will be reflected off. This can cause "arcing" or crackles and sparks to occur which can in turn damage the machine. So avoid kitchen foil for the same reason.
Combination Microwave Ovens
These are simply a microwave oven which also has a fan oven element and/or a grill element. This is a really useful piece of kit as it will do everything that a microwave oven can do, but it will also work as a fan oven (and grill sometimes). Any function will cook independently or the functions can be used in combination. Combination cooking will offer the speed of microwave cooking but also give food the colour of roasting. This can be a great way to cook meats and in particular chicken.
If you are stretched for space, a combination microwave oven is worth considering.
