Kitchen Appliances & Fixtures

Microwave Oven Common Questions and Troubleshooting Tips

How does Microwave Oven help cooking?

In normal cooking, the food is heated by an external heat source through conduction or convection. In microwave cooking, the heat is generated inside the food itself. The principle of microwave cooking is that the microwaves cause the millions of molecules to turn over and return very rapidly and to rub against each other. The rubbing of the molecules together generates frictional heat in the same way that the heat is generated when both hands are rubbed together. This method of cooking is faster & economical.

Will Microwave Oven increase my electric bills?

No. Microwave energy penetrates food below the surface causing food to cook rapidly. MWO does not need any pre-heating of the oven air. MWO generates heat directly in the food, without first heating the cooking utensil. Hence, in most cases, a microwave oven consumes less electrical energy to cook food than any normal electrically operated cooking range that finally does not increase electrical bill.

By any chance, do microwaves destroy nutrients?

No, microwaves do not destroy nutrients in food when compared with other methods of cooking. They do destroy harmful bacteria through normal cooking.

What type of utensils can be used in a Microwave oven?

One can use Ceramic, Chinaware, Porcelain, Glass, Thermoplastic wares, and Aluminum foils. The utensils should not have any metal trimmings or decoration.

The above said timings are at maximum power levels of Microwave, the electricity consumption decreases correspondingly with lower power levels, which please note. Like most appliances, it is better to safeguard your Microwave Oven against wide voltage fluctuations and hence use a stabilizer of 1.5 KVA or so. This will also ensure exact cooking time.

How is microwave reheating different?

Surplus/leftover food can be reheated quickly without losing its original flavor or taste therefore, maintaining its freshness. In addition, food that was cold & tasteless can be made hot and tasty in a few minutes in a Microwave Oven.

Can my oven be operated without the turntable?

No, generally microwave ovens are designed to operate with the turntable in its place. 

Can turntable in the oven reverse direction?

Yes. The turntable of Microwave Oven is expected to reverse its direction at random intervals.

How much time is required to cook on a microwave?

Microwave cooking is very fast when compared with conventional cooking.
For servings i.e. (250-300 g), see the table.
Type Time required to cook
Rice 15 - 20 minutes
Vegetables 7 - 15 minutes
Dal items 25 - 35 minutes
Continental 3 - 25 minutes (as per style/dish)
Sweets 15 - 30 minutes
Chicken / meat items 15 - 35 minutes
Fish items 7 - 15 minutes

What types of dishes can be cooked in a microwave oven?

You can easily make following food varieties in Microwave Oven:

Does Microwave oven emit radiation that is harmful to health / causes cancer?

Microwave oven is a non-ionizing appliance, that does not change the physical and chemical properties of food, and it only heats the same.

Microwaves when exposed to the food get completely absorbed that help in heating / cooking the food. The heat is generated by causing friction between the microwaves and the food molecules. The microwaves are completely converted into heat and there is nothing left behind, in the food. Microwaves are just another form of energy and hence are safe, not harmful.

Will Microwave Oven be damaged if operated without food inside?

A microwave oven should not be operated without food or liquid inside to absorb the microwave energy. It is not likely that an oven that has been operated for a short time while it is empty will be damaged. However, it is advised to stick on to the instructions given in the user manuals.

Why does the cabinet of the Microwave Oven become hot when it is in use?

Heat is generated by the electronic components like magnetron and the food being cooked. Therefore, the Microwave Oven gets heated-up, after it is used.

Why does accumulation of moisture inside the oven is seen, on certain occasions, after cooking food?

Condensation is a normal phenomenon or result of the cooking process. When the food that has high water content is cooked, the condensation is significantly visible. Condensation may be more noticeable during the periods when the weather is humid.

Aluminum being metal, is it safe to use aluminum foil in the microwave oven, as stated in the user manual?

Small, narrow strips of very thin aluminum foils are suggested for protecting the part of food that appear to be cooking or defrosting more quickly than the rest of the food item, e.g., the tips of the wings of a chicken or the edge of a roast, steak, etc. This limited use of Aluminum foil is safe inn Microwave Oven.

What should I do if someone overcooks the popcorn in Microwave Oven and there is a long lasting odor?

Most strong food odors can be removed by placing a mixture of 3 cups of water, 2 tablespoons of lemon juice and 10-12 cloves in Microwave Oven and bringing it to a rolling boil. Allow the mixture to cool on its own in the oven without opening its door. The steam generated therein will help to remove the odor.

How should I clean the inside of my oven?

Cleaning is easy because little heat is generated to the interior surfaces; so, there is no baking and setting of spills or spraying. To clean the interior surfaces, wipe with a soft cloth and warm water. Do not use abrasives or harsh cleaners or scouring pads. In case of heavier soil, use baking soda or a mild soap and rinse thoroughly with hot water. As a part of basic precaution, one should take care and ensure that nothing falls inside Microwave Oven.

Can microwaves leak radiation?

Normally Microwave Ovens do not leak radiation. Old or faulty door seals are the most common causes of microwave radiation leakage. Mechanical abuse, collection of dirt, or simple wear and tear of continued use can cause door seals to be ineffective. 

What is ideally suggested shape of microwave dishes?

Round and ring shaped dishes give the most even cooking results. In addition, since microwaves penetrate to a depth of 20 to 35 mm, shallow and straight-sided containers are better. In other words, round, shallow and straight-sided dishes are ideal for microwave cooking.

Why does the utensil remain cool in Microwave Oven?

Microwaves are able to pass through most materials except metals. (Refer to user manual - Cookware). If the material of utensil can transmit the microwaves without absorbing them, it remains cool. Heat is created in food itself so, as cooking progresses, it may become warm, as heat is conducted from the cooked food to the utensil by conduction. Hence in comparison to normal cooking the utensil will remain cool in Microwave Oven.

Do microwaves interfere with the functioning of other electronic appliances?

Normally they do not interfere. The Bureau of Indian Standards have set the required frequency of microwave ovens at 2450 MHZ, which does not interfere with radio, T.V or F.M broadcasting, as their features are different.

How can a microwave food be more nutritious than food cooked in conventional manner?

The nutritive value of food consumed is determined to a large extent by the method and duration of cooking. Vitamins and the other nutrients deteriorate with time at high temperature. Hence, important losses of nutrients occur in conventional heating of foods, especially in frying and cooking over long periods. Microwave heating is a rapid heating method, which has a potential benefit for the heatable nutrients. Since it requires very little or no cooking liquid, it enhances the retention of water-soluble nutrients. It does not use metal cooking utensils, hence eliminating the presence of trace metals.

Working of Microwave

Like a radio station in the air, magnetron tube of Microwave Oven into an oven cavity sends microwaves. Inside the oven, they "bounce around" to give even cooking.

Microwaves "bounce-off" of the metal. Hence, we cook in a round or six-sided box to avoid their moving out into the room. This makes all very safe to use. The microwaves pass through plastic or glass, like sunshine goes through a windowpane, with no effect at all. Therefore, we cook in utensils made from these types of materials. The microwaves are attracted, like magnets, to the fat, sugar, and water within the food. Water molecules are very good absorbers of microwaves, sugar, and fat are better and salt is best. Therefore, foods high in fat, sugar, and salt will cook faster and get hotter than foods made up primarily of water like vegetables.

Microwaves penetrate the foods about 20-30 mm in all directions (top-bottom and sides) causing the water molecules to move and vibrate against one another at the rate of 2 billion times per second. It may be noted that the microwaves do not actually cook the food but the friction caused by the vibrating molecules produce the heat. Microwaves do not actually touch most of the food they cook. The heat from the vibrating molecules on the outer edges of the food must go somewhere. It is by "conduction" this heat moves inward, layer by layer, to cook the food. Therefore, cooking larger, denser foods starts on the edges and heat is conducted to the center.
Stirring helps food to cook more uniformly as it redistributes heat from the outer layers of the food to the inner layers. Arrangement of the food, the style of dish (round vs. square), denseness of food, etc. affect in microwave cooking.

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