With the arrival of microwaves in the 70s, cooking evolved to a new level. When people came to know how fast this appliance could cook or heat the prepared food for them, they became tempted to use it more often. They also have many other advantages over a traditional oven. For instance, they do not need to be heated in advance, which can save energy.
Many believe that a microwave cooks a dish from the inside out, which makes it cook it faster. But, that is not the exact science behind it. To learn how does a microwave work, keep reading further.
How Does A Microwave Work
1. Parts Of A Typical Microwave
A typical microwave oven comprises of several parts, namely:
• A cooking cavity: It is a box-like structure in which the food is placed for cooking or heating. This box is made of metal that stops the harmful rays from going out of the oven box.
• A Magnetron: This device is responsible for emitting the microwaves, which are used for heating or cooking the food.
• A lightbulb: This component is there to provide illumination
• A turntable: The rotating table is used for placing the food upon it for cooking it.
• A waveguide: This is the passage through which the microwaves travel to reach the stirrer unit.
• Stirrer: It is like a small fan. The microwaves delivered to it through the waveguide are spread throughout the cooking cavity.
Depending on your microwave model, you may have additional components and features built-in. However, a typical one comprises of the above parts.
2. Function Of A Microwave
With the help of microwaves, a modern oven can guide the heat energy to the food molecules directly. These microwaves act similar to electromagnetic waves travelling through the air in a zigzag pattern and influenced by magnetism and electricity.
Microwaves are also a type of radio waves with very short wavelengths. A modern microwave oven comprises of microwaves that are just 5 inches long. Even though they have a short length, they can still transmit large quantities of energy. Unfortunately, microwaves can be harmful to humans, as these waves can destroy the cells and tissues. So, the waves are trapped inside the high-quality metal boxes without a chance to escape outside.
3. How Does A Microwave Cook Food?
This process of cooking is carried out in the following step:
• Once the food is kept on the turntable top, and the power is turned on, the cooking process starts.
• Through the power supply, the magnetron starts generating microwaves inside the metal box.
• The generated microwaves travel from the magnetron through the waveguide channel. These waves then reach the stirrer fan.
• The stirrer spreads the microwaves inside the cavity.
• This turntable keeps spinning slowly for letting the waves cook the food thoroughly.
• The microwaves keep bouncing back and forth, reflecting from the metallic surface of the box. In this process, these waves also hit the food laid on the turntable.
• Instead of reflecting them, the food lets the waves pass through it. While passing through the food, the food molecules start vibrating due to excitement from the microwaves.
• As per science, molecules that vibrate have heat in them. So, with faster vibrations, the food becomes hotter.
• The passing waves heat the molecules of the food evenly, thus cooking the dish.
4. The Concept Of Inside-Out Cooking
As mentioned before, people believe that a microwave oven tends to cook a dish from the inside out. However, this is not true. A microwave oven tends to cook a meal using radiation. This radiation passes through the food evenly. Therefore, all the molecules in the food get heated up at the same time.
On the other hand, a conventional oven relies on the process of conduction. The heat from such an oven spreads from the outer layer of the food towards the inner layer. In most cases, the heat may never even reach to the very centre of a dish. That is why certain dishes get burnt around the edges and do not even cook appropriately in the middle unless the dish is cooked correctly.
In fact, the cooking process depends upon the ingredients of food. Microwaves will cook a dish with more fluid content faster, such as a pie. In such a case, the liquid molecules (which are present in the middle) will cook first, and the outer covering cooks after that. So, it appears as if the dish is cooking inside out.
You may have noticed that a pie that has been heated using a microwave for a couple of seconds is hot in the centre, but barely warm at the crust. Similarly, foods with even distribution of water will be heated evenly.
The concept of cooking with a microwave oven solely depends upon the time it takes for each type of food molecule to vibrate energetically. The ones that vibrate faster have more heat in them and vice versa.
Hope that you have understood how does a microwave oven work. Unlike a conventional oven, a microwave oven has enabled people to get their meals cooked at a much faster rate. Remember to use these appliances safely and avoid experimenting with something that you are not supposed to.