How Microwave Preset Buttons Work (If They Even Do)

Have you ever used the preset buttons on a microwave? These buttons scattered around the microwave controls don't literally say "preset" on the label — instead, these options claim to cook foods in specific ways, like the buttons simply called "popcorn" or "baked potato" or even just "defrost." You've likely seen these labels on your appliance, and it's entirely possible that you've never once touched them. If you're like me, you like to microwave the old-fashioned way: by nuking the food for a minute, touching it to see if it's hot, and then placing it back in if it's still cool.

Should you use the microwave's popcorn button then, or those medium or low power options? Those preset buttons are deceptively simple. Microwaves work by bouncing microwave particles through the food (using a fancy tube called a magnetron), which vibrate the molecules in your food and heat them up. Many presets only control when the power is switched on or off while the food is cooking. By cycling the fancy magnetron tube on or off at different times during the cooking process, it can create an ideal heat level to warm up certain foods (or at least, it's supposed to). Other presets don't do anything beyond set a timer for a certain food's estimated cooking time. So, you might need to do a trial run before deciding whether or not your preset buttons work for you (and what dishes they work best with). 

To give an example: when you hit the defrost button, the microwave is essentially just switching the power on and off constantly, and the microwave's interior is cooled to about 20 or 30 percent of its normal power, per Whirlpool. It can gently thaw frozen food without overdoing it — unfortunately, it's not always reliable, so it's worth checking on your item every so often.

If you don't hit the right preset button, is that a microwave mistake that can ruin your food? How well these dedicated settings actually work is often up for debate. Lots of timed buttons have a tendency to overshoot and possibly burn the dish, and the time and intensity for the presets can vary to a frustrating degree between microwave models. Chances are, your food's packaging already has specific microwave instructions which are more helpful than the presets. If you need to be messing with the power settings before microwaving food beyond the default high setting, the instructions should say so.

With that said, some newer microwaves can do slightly more with those presets. If your microwave comes equipped with a steam sensor, it's not just guessing the best time for your popcorn: it's measuring steam and humidity to decide when the food is properly prepared, and that can be more helpful. It's worth checking whether your microwave model has sensor cooking, but it's certainly not crucial for warming up your meal.