# Popcorn button on microwave oven. How does it work? **URL:** \ **Category:** Factual Questions\ **Created:** [August 3, 2014, 8:20pm UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739 "2014-08-03T20:20:49Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [August 3, 2014, 8:20pm UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/1 "2014-08-03T20:20:49Z")
Put the bag in, press the “popcorn” button, and the microwave oven knows _precisely_ when to shut off. How does it do this? In [this](http://boards.straightdope.com/sdmb/showthread.php?t=348848) SDMB thread from 2005, **Q.E.D.** said the oven measures the humidity level in the chamber. I’m a bit dubious that this is how it works. RH sensors are not all that reliable or accurate. Plus I would think the RH level would get very high very quickly soon after the corn starts popping. I’m thinking a more reliable method is to use an audio transducer (microphone) to count the popping rate (pops/second). Is this how it works? ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [August 3, 2014, 8:58pm UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/2 "2014-08-03T20:58:30Z")
It could also just be that bags of popcorn are pretty consistent, and so the microwave knows what time it’ll need. ---
**Author:** ![DrCube](https://avatars.discourse-cdn.com/v4/letter/d/a3d4f5/32.png) [@DrCube](https://boards.straightdope.com/u/DrCube)\ **Post date:** [August 3, 2014, 10:46pm UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/3 "2014-08-03T22:46:12Z")
I’m pretty sure some count the pops and others use their best guess for time. I’ve had microwaves that popped a perfect bag every time (apparently using some sort of sensor, I presume audio) but my current microwave, which is pretty good otherwise, will burn your popcorn if you just let the popcorn setting do all the work. ---
**Author:** ![Rick\_Kitchen](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rick_kitchen/32/522_2.png) [@Rick\_Kitchen](https://boards.straightdope.com/u/Rick_Kitchen)\ **Post date:** [August 3, 2014, 10:53pm UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/4 "2014-08-03T22:53:11Z")
Ours is just a timer. You push the Popcorn button and the timer sets itself to 1.75 minutes, which is a strange measurement, and then you have to push the Start button. ---
**Author:** ![Chefguy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chefguy/32/138_2.png) [@Chefguy](https://boards.straightdope.com/u/Chefguy)\ **Post date:** [August 3, 2014, 10:56pm UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/5 "2014-08-03T22:56:59Z")
I’ve pushed mine dozens of times and still no popcorn; I think it must be busted. ---
**Author:** ![jasg](https://avatars.discourse-cdn.com/v4/letter/j/f0a364/32.png) [@jasg](https://boards.straightdope.com/u/jasg)\ **Post date:** [August 4, 2014, 12:42am UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/6 "2014-08-04T00:42:10Z")
> [@Chefguy](#): > > I’ve pushed mine dozens of times and still no popcorn; I think it must be busted. Is it connected? ---
**Author:** ![Chefguy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chefguy/32/138_2.png) [@Chefguy](https://boards.straightdope.com/u/Chefguy)\ **Post date:** [August 4, 2014, 1:03am UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/7 "2014-08-04T01:03:29Z")
> [@jasg](#): > > Is it connected? Whoosh. It was a joke, son. ---
**Author:** ![jasg](https://avatars.discourse-cdn.com/v4/letter/j/f0a364/32.png) [@jasg](https://boards.straightdope.com/u/jasg)\ **Post date:** [August 4, 2014, 1:09am UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/8 "2014-08-04T01:09:21Z")
> [@Chefguy](#): > > Whoosh. It was a joke, son. I know, was trying to set up another joke but failed… ---
**Author:** ![Chefguy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chefguy/32/138_2.png) [@Chefguy](https://boards.straightdope.com/u/Chefguy)\ **Post date:** [August 4, 2014, 1:15am UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/9 "2014-08-04T01:15:03Z")
> [@jasg](#): > > I know, was trying to set up another joke but failed… :smack: ---
**Author:** ![dropzone](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dropzone/32/7515_2.png) [@dropzone](https://boards.straightdope.com/u/dropzone)\ **Post date:** [August 4, 2014, 1:21am UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/10 "2014-08-04T01:21:16Z")
I have no reason to expect that the popcorn button sets into motion a pop counter or any such thing. I also have no expectation that it will do anything but set the timer for the 1.75 minutes on high or whatever it is that typical popcorn packs suggest. Then I use my ears. Okay, I really use a cheap air popper and plain kernels. They’re foolproof and I can control the salt and use real butter. ---
**Author:** ![Artemis\_Tardis](https://avatars.discourse-cdn.com/v4/letter/a/4bbf92/32.png) [@Artemis\_Tardis](https://boards.straightdope.com/u/Artemis_Tardis)\ **Post date:** [August 4, 2014, 1:24am UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/11 "2014-08-04T01:24:56Z")
I have had a few microwaves. All of them had only a timer for popcorn. I still prefer to make my own popcorn (without the bag), by putting popcorn kernels on a paper bag with some salt and oil. Works really well. ---
**Author:** ![panache45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/panache45/32/64_2.png) [@panache45](https://boards.straightdope.com/u/panache45)\ **Post date:** [August 4, 2014, 1:31am UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/12 "2014-08-04T01:31:21Z")
I’m wondering whether there could be a scale under the platter. Or isn’t there measurable time required for a larger bag, or is the number of kernels irrelevant? ---
**Author:** ![Irishman](https://avatars.discourse-cdn.com/v4/letter/i/b487fb/32.png) [@Irishman](https://boards.straightdope.com/u/Irishman)\ **Post date:** [August 4, 2014, 1:35am UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/13 "2014-08-04T01:35:10Z")
Mine doesn’t appear to work by time. It doesn’t display a time until the last 15 seconds. It doesn’t appear to work by sound, because the kernels are still popping regularly when the timer kicks in. I think mine is a humidity sensor. It works pretty good. I typically hit the 30 second button, then turn off by hand after an additional 10 seconds. The full 30 seconds burns, 20 seconds is too long, but 10 seconds squeezes out several more good pops. Yeah, I could do it by time, too, but the popcorn button ends if I get distracted. ---
**Author:** ![SeaDragonTattoo](https://avatars.discourse-cdn.com/v4/letter/s/df705f/32.png) [@SeaDragonTattoo](https://boards.straightdope.com/u/SeaDragonTattoo)\ **Post date:** [August 4, 2014, 3:45am UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/14 "2014-08-04T03:45:05Z")
My microwave has a fairly accurate sensor. Back when I bought it and read the instruction book, it stated the sensor uses steam + what it’s set for to tell when something is done. It also had fairly specific instructions as to how to prepare certain items in order for the sensor to work well. For instance, disregard whatever instructions come with a frozen dinner, simply put a 2" slit in the center of the cellophane cover and then press the “frozen dinner sensor” button. Baked potatoes, pierce with a fork twice on opposing sides and then press the “baked potato sensor” button. When I follow the instructions according to the microwave, stuff comes out perfectly. Frozen vegetables are perfect when covered with saran wrap with one small corner uncovered, but if I put them in uncovered it thinks they’re done when they’re still cold in the middle. Microwave popcorn comes out perfectly. I’m quite certain the sensor is programmed to use a certain amount of steam as a trigger for the timer. As noted by another poster, when it’s set to “sensor cook” it doesn’t have the time displayed initially, it just scrolls “sensor cook” until it senses a certain amount of steam, and only when there’s a certain amount of time it has calculated to be left does it put a time countdown on the display. That countdown time is not consistent. It can be anywhere from 2 minutes to 15 seconds and doesn’t do the same final time for the same setting. ---
**Author:** ![GusNSpot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gusnspot/32/436_2.png) [@GusNSpot](https://boards.straightdope.com/u/GusNSpot)\ **Post date:** [August 4, 2014, 4:45am UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/15 "2014-08-04T04:45:28Z")
We use several brands of Microwave popcorn. We set the timer to 2minutes, 35 seconds and it works great. The only built in timer like thing we do is sometimes ‘defrost’ on something big. ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [August 4, 2014, 10:58am UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/16 "2014-08-04T10:58:08Z")
> [@SeaDragonTattoo](#): > > Microwave popcorn comes out perfectly. I’m quite certain the sensor is programmed to use a certain amount of steam as a trigger for the timer. Perhaps. But many times I’ve made two bags of popcorn in quick succession. If the oven used an RH/T sensor, you would think the second bag would not pop correctly. A timer would be the simplest approach. But the popcorn button works equally well for smaller and heavier bags. ---
**Author:** ![kayaker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayaker/32/441_2.png) [@kayaker](https://boards.straightdope.com/u/kayaker)\ **Post date:** [August 4, 2014, 11:18am UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/17 "2014-08-04T11:18:25Z")
> [@jasg](#): > > Is it connected? Yeah, I push the button and Vinnie brings me popcorn. ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [August 4, 2014, 12:27pm UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/18 "2014-08-04T12:27:10Z")
Fucking magnetrons! ---
**Author:** ![Max\_Torque](https://avatars.discourse-cdn.com/v4/letter/m/e9bcb4/32.png) [@Max\_Torque](https://boards.straightdope.com/u/Max_Torque)\ **Post date:** [August 4, 2014, 1:49pm UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/19 "2014-08-04T13:49:19Z")
Ours at home has three popcorn settings depending on the size of the bag. As you press the button, it cycles between, I believe, 3 ounce, 2.7 ounce, and 1.6 ounce sizes. Some of y’all should press your “popcorn” button more than once and see what happens. ---
**Author:** ![Tom\_Tildrum](https://avatars.discourse-cdn.com/v4/letter/t/e95f7d/32.png) [@Tom\_Tildrum](https://boards.straightdope.com/u/Tom_Tildrum)\ **Post date:** [August 4, 2014, 2:29pm UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/20 "2014-08-04T14:29:53Z")
> [@Rick\_Kitchen](#): > > Ours is just a timer. You push the Popcorn button and the timer sets itself to 1.75 minutes, which is a strange measurement, and then you have to push the Start button. Interesting. Presumably this means two minutes fifteen seconds, but why wouldn’t it just say that? I don’t use my popcorn button, but my potato button has always been successful. [Next page](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739.md?page=2)