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How We Tested Microwave Ovens

Wednesday June 29, 2022

When exploring your options in the world of kitchen appliances, you can easily end up overwhelmed with all the choices on the market. Our aim is to demystify the options and make your decision easier. We bought the top microwaves currently available and put them through the wringer to see which model came out on top. Our testing process is split into four different metrics, with a handful of sub-tests in each metric.

in our heating tests, such as the pizza heating test shown above on...
In our Heating tests, such as the Pizza Heating test shown above on the AmazonBasics microwave, we used a Laser Infrared Thermometer to measure for consistent temperature across the food surface area.
Credit: Laura Casner


For our heating metric, we looked at how well each product heated up different types of foods and how quickly and evenly they heated using a pair of side-by-side tests. We used a plate of breakfast sausage, green beans, and potatoes to represent a plate of leftovers, a bowl of canned soup, and two slices of pizza as our test food items. Each was heated according to instructions for the power level for each microwave and then scores were determined based on temperature readings across each type of food. For the mixed plate of leftovers, we looked at the range of temperatures across each type of food, how closely the temperature of each type of food was to the others, and if all three were warmed enough to serve.

the nostalgia yields different temperatures for different foods, so...
The Nostalgia yields different temperatures for different foods, so it's not great for leftovers.
Credit: Laura Casner

To measure and compare how quickly each product heated up food, we took 125 ml of water in a beaker in each microwave and ran them for 45 seconds, comparing the temperature increase to award points.

for our heating speed test, we measured how much the temperature...
For our Heating Speed test, we measured how much the temperature increased in 124mL of water when heated for 45 seconds on high.
Credit: Laura Casner

We ranked and rated the evenness and consistency of heating by spreading out a thin layer of marshmallow fluff on a piece of parchment paper and heating it up in each microwave.

we found some very uneven heating with the toshiba em925a5a in our...
We found some very uneven heating with the Toshiba EM925A5A in our heat map test.
Credit: Laura Casner

We wanted to see even browning across the marshmallow, without any raw or burned spots.

the miniature lasagna did a great job of highlighting differences in...
The miniature lasagna did a great job of highlighting differences in how each microwave heats up food.
Credit: Laura Casner

Frozen Foods

For our frozen foods metric, we used three types of prepared food to test performance: Hot Pockets, a frozen burrito, and an individual serving of lasagna. For each test, we used a series of instant-read digital kitchen thermometers to compare the thermal gradient throughout each type of food.

we found that one side was just a tiny bit cooler than the rest...
We found that one side was just a tiny bit cooler than the rest during our Panasonic NN-SB458S heat test.
Credit: Laura Casner

We also checked to ensure that each type of food reached the recommended serving temperature.

the toshiba em131a5c defrosted the entire block of turkey.
The Toshiba EM131A5C defrosted the entire block of turkey.
Credit: Laura Casner


We used a one pound block of frozen ground turkey for this metric, attempting to defrost it according to the instructions for each microwave. After the conclusion of the defrosting cycle, we scraped off all the completely thawed meat and weighed it to determine scores. We also deducted points if any of the turkey was prematurely cooked.

the toshiba em131a5c does a great job with premade frozen items.
The Toshiba EM131A5C does a great job with premade frozen items.
Credit: Laura Casner

Ease of Use

Our last round of tests scored and compared how user-friendly and easy to use each microwave is, including how effective the preset functions are using the popcorn button as our test options.

We started by looking at the interface for each appliance, specifically if they have a +30 seconds button that automatically start the microwave and if they have one-touch features. For example, if you hit the "2" button, does it automatically put two minutes on the clock and start it.

the panasonic nn-sb458s doesn't have quite as many convenience...
The Panasonic NN-SB458S doesn't have quite as many convenience features as some of the others.
Credit: Laura Casner

We then looked at the internal lighting and how easily each product slid around on a smooth countertop when opening the door or hitting buttons. We were looking for products that easily remained in place with normal use. Finally, we assessed the popcorn preset function by making a bag of popcorn in each microwave. Scores were based on the number of kernels that remained unpopped and whether any were burned.

the popcorn preset on the nostalgia left a decent number of kernels...
The popcorn preset on the Nostalgia left a decent number of kernels un-popped.
Credit: Laura Casner

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GearLab is founded on the principle of honest, objective, reviews. Our experts test thousands of products each year using thoughtful test plans that bring out key performance differences between competing products. And, to assure complete independence, we buy all the products we test ourselves. No cherry-picked units sent by manufacturers. No sponsored content. No ads. Just real, honest, side-by-side testing and comparison.

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