Microwaving is cooking food in a microwave oven. It is often quicker and more convenient than equivalent methods such as boiling or baking. Many vegetables, for example, can be microwaved instead of boiled or steamed.
As with other cooking instruments some care must be taken and food should be checked regularly if it is microwaved for a long period. Aluminium foil and other metal items should never be put in a microwave. Always use a container labelled "microwave safe" to avoid toxins in foods. Similarly, metal decorations on the dishes can damage the dishes and denature the food.
Items are often extremely hot after being microwaved, so take care when removing them.
Microwave cooking includes a number of methods which at first sight are similar to those used in a conventional oven. The methods all make use of a microwave oven, and that might be either a simple microwave heating device, or one that includes the additional techniques of steaming, crisping, or grilling.
Although microwave cooking is in general use, it is usually acknowledged as having more limited scope than conventional ovens. That said, for those tasks for which it is particularly useful, it is both efficient in energy terms and in the time it takes to complete its tasks.
The basic microwave oven heats by the movement of water in the foods. This movement generates the heat that is used for cooking. This technique cannot in itself cause browning, so the above-mentioned combination ovens have been designed with additional heating elements (grilling). Like conventional ovens, some foods are dried out at their surface during cooking, so both the addition of water and steaming are commonly used. Additional crisping plates are used to make foods like pizza and roast potatoes crisp on their surface.
Containers for Microwaving
Because microwaves cannot effectively penetrate food beyond about one or two inches, food in excess of these dimensions depends on conduction of heat from the absorption regions to cook them. For this reason microwave cooking has adopted a number of necessary conventions.
Adjusting Cooking Times for Power Level
If the microwave oven used for the recipe did not have a 750W or 350W setting, but had a 600W and a 300W setting instead, then all of the cooking times could be adjusted for the new power levels. The new cooking times would just become (750/600) times 6, and 350/300 times 10. For example:
The old cooking times were 6 minutes at 750W and 10 minutes at 350W. The ratio is always: "Recipe quoted power divided by machine power being used" These times are therefore just: (750/600)*6 = 7.5 minutes at 600W and (350/300)*10 = 11.91 or about 12 minutes at 300W So the old cooking times are increased slightly in proportion to the change in power.
The change could be calculated for a more powerful oven too, using the same proportionate method. That is to say, power changes can always be calculated on the assumption of proportionality. In fact it is likely that cooking times will be adjusted for both changed power settings and for changed weights of ingredients. In this event the table in the next section may prove useful.
Adjusting Cooking Times for Changed Weights
If the weights of the food to be cooked much differ from those of the recipe then the cooking times will be wrong. It is possible to adjust the cooking times to take account of these changes, but the changed cooking times do not work in proportion to the change in the way of power level changes. Specifically, if you double a recipe quantity, you should not necessarily double the time; it is more likely to be closer to a multiple of 1.5 times the original recipe time; not twice.
The figures given in the table are approximations for small changes, and should not be used beyond a single doubling or halving of the recipe time; that is, they cannot be used four times to increase by eight, since large errors will occur. Make gradual changes minute by minute when near the approximate time, and check the cooking each time to get it right.
Microwave Recipes for Basic Foods