# 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:** 14\ **Page:** 2
**Author:** ![tim-n-va](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tim-n-va/32/3001_2.png) [@tim-n-va](https://boards.straightdope.com/u/tim-n-va)\ **Post date:** [August 4, 2014, 2:33pm UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/21 "2014-08-04T14:33:54Z")
> [@Max\_Torque](#): > > 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. This is how ours works and it screws me up now that most brands have reduced from the 3.5 oz bags. ---
**Author:** ![tim-n-va](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tim-n-va/32/3001_2.png) [@tim-n-va](https://boards.straightdope.com/u/tim-n-va)\ **Post date:** [August 4, 2014, 2:35pm UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/22 "2014-08-04T14:35:07Z")
> [@Tom\_Tildrum](#): > > 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. I would think that 1.75 minutes is 1:45 not 2:15. It is not 1 minute and 75 seconds. ---
**Author:** ![Spud](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/spud/32/347_2.png) [@Spud](https://boards.straightdope.com/u/Spud)\ **Post date:** [August 4, 2014, 2:49pm UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/23 "2014-08-04T14:49:40Z")
> [@tim-n-va](#): > > I would think that 1.75 minutes is 1:45 not 2:15. It is not 1 minute and 75 seconds. You must be from one of those foreign countries where they use metric time. ---
**Author:** ![tim-n-va](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tim-n-va/32/3001_2.png) [@tim-n-va](https://boards.straightdope.com/u/tim-n-va)\ **Post date:** [August 4, 2014, 3:16pm UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/24 "2014-08-04T15:16:49Z")
> [@Spud](#): > > You must be from one of those foreign countries where they use metric time. No, just someone who thinks number separated by a colon means something different than numbers separated by a decimal. ---
**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, 3:19pm UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/25 "2014-08-04T15:19:27Z")
> [@tim-n-va](#): > > I would think that 1.75 minutes is 1:45 not 2:15. It is not 1 minute and 75 seconds. You may be right – certainly, your reading is more sensible – but how would that count down? ---
**Author:** ![tim-n-va](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tim-n-va/32/3001_2.png) [@tim-n-va](https://boards.straightdope.com/u/tim-n-va)\ **Post date:** [August 4, 2014, 3:32pm UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/26 "2014-08-04T15:32:21Z")
> [@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. What does the display read after you push the Start? ---
**Author:** ![DingoelGringo](https://avatars.discourse-cdn.com/v4/letter/d/9d8465/32.png) [@DingoelGringo](https://boards.straightdope.com/u/DingoelGringo)\ **Post date:** [August 4, 2014, 3:37pm UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/27 "2014-08-04T15:37:42Z")
> [@Crafter\_Man](#): > > 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? How does it work? Oh pretty good! But it is actually a timer, not magic or humidity levels or other mystical things. ---
**Author:** ![DingoelGringo](https://avatars.discourse-cdn.com/v4/letter/d/9d8465/32.png) [@DingoelGringo](https://boards.straightdope.com/u/DingoelGringo)\ **Post date:** [August 4, 2014, 3:40pm UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/28 "2014-08-04T15:40:42Z")
> [@panache45](#): > > 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? Scale? Are you suggesting that popped corn weighs less or more than unpopped corn? ---
**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, 3:44pm UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/29 "2014-08-04T15:44:24Z")
> [@DingoelGringo](#): > > Scale? Are you suggesting that popped corn weighs less or more than unpopped corn? I think it’s more a matter of a heavier bag requiring more time than a lighter one. My microwave certainly does not have a scale, though, as certain defrost settings require me to input the weight of the product. ---
**Author:** ![brix11](https://avatars.discourse-cdn.com/v4/letter/b/c37758/32.png) [@brix11](https://boards.straightdope.com/u/brix11)\ **Post date:** [August 4, 2014, 6:03pm UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/30 "2014-08-04T18:03:20Z")
> [@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. The 1.75 refers to the size of the bag in ounces. That is for [snack-size bags](http://parkridgestationers.com/ItemDisplayF.aspx?D1=Microwave-Popcorn-Movie-Theatre-Butter-175-oz-Bags-10Box&ItemID=DFD28783&cm_vc=ID_AlsoConsider&cm_sp=Product-_-ID_AlsoConsider-_-DFD28783&PVT=AC1). I bet if you push the button twice, you’ll get the other common size, 3.5 oz. ---
**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, 7:32pm UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/31 "2014-08-04T19:32:42Z")
> [@DingoelGringo](#): > > How does it work? Oh pretty good! But it is actually a timer, not magic or humidity levels or other mystical things. I just looked up a Sharp Sensor microwave manual, and it specifically says for the sensor it uses the vapor from popcorn bags to gauge cooking time. It also says specifically to use only made-for-microwave popcorn bags for the sensor to work properly. ---
**Author:** ![Folacin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/folacin/32/3195_2.png) [@Folacin](https://boards.straightdope.com/u/Folacin)\ **Post date:** [August 4, 2014, 8:14pm UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/32 "2014-08-04T20:14:03Z")
> [@tim-n-va](#): > > I would think that 1.75 minutes is 1:45 not 2:15. It is not 1 minute and 75 seconds. my previous microwave could be set for 1 minute, 75 seconds. I’m not sure about the current one (I mostly use the sensor setting), but on the old one, pressing 1-7-5 would get you 1 minute, 75 seconds of heating. I realize that if it were a programmed timer, it wouldn’t do that (and like the weight suggestion down thread), but it’s not an impossibility. ---
**Author:** ![dstarfire](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dstarfire/32/5762_2.png) [@dstarfire](https://boards.straightdope.com/u/dstarfire)\ **Post date:** [August 5, 2014, 1:11am UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/33 "2014-08-05T01:11:36Z")
Read an article just the other day about some company developing a microwave with an audio sensor that could get popcorn right every time, for any size bag (pop is distinct from normal hum/fan noise). **For the 1.75 tangent:** On my microwave, pressing the popcorn button once produces 1.75, a second press produces 2.5 . This was NOT the actual time it ran for, rather it seems to refer to the size of the bag (in ounces, maybe?). ---
**Author:** ![crowmanyclouds](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crowmanyclouds/32/19884_2.png) [@crowmanyclouds](https://boards.straightdope.com/u/crowmanyclouds)\ **Post date:** [November 23, 2023, 4:50am UTC](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739/34 "2023-11-23T04:50:18Z")
More than anyone could want to know about the ‘popcorn button’! _What’s the deal with the popcorn button?_ ~ Technology Connections > **[What's the deal with the popcorn button?](https://www.youtube.com/watch?v=Limpr1L8Pss%2F1)** > > Try it. You know you want to.Referenced Videos:The Antique Microwave Oven that's Better than Yourshttps://youtu.be/UiS27feX8o0And the follow-up to that oneht... [Previous page](https://boards.straightdope.com/t/popcorn-button-on-microwave-oven-how-does-it-work/694739.md?page=1)