Woman heating food in microwave
What Microwave Power Levels Actually Indicate
The microwave has come a long way since its creation in 1945 by engineer Percy Spencer. While this appliance is in over 90% of American homes, many aren't aware of how it works.
The power settings on a microwave intermittently turn on and off the electromagnetic waves (aka microwaves) that radiate and heat up our food.
Many modern microwaves have at least five settings, and some have power levels that range from 1-10. We can adjust the power level to suit whatever we are trying to cook or heat.
By default, the microwave cooks things at the maximum level, but if it were reduced to a medium setting, or 5, the microwave energy would only be on for half of the time.
As a rule of thumb, the default, or high power, should be used for liquids like water, soup, and beverages, along with foods that are less than ½ inch thick, such as popcorn.
Medium or 50% power should be used for items that can't be stirred, such as lasagna, whole roasts, or chicken. This setting is also useful for softening things like butter.
A medium or low power setting is best for dairy or delicate sauces. Grains require a more gentle heat and should be microwaved at a low setting to avoid burning or spilling over.
Lastly, defrosting frozen food requires a lower power level because microwaves need liquid to generate heat, so after it melts the outer part of the item, it can heat the rest.