When the 'popcorn' button on the microwave is 3 seconds too long
I've never fully understood how the 'popcorn' button on microwaves work (I've read different things that may or may not all be true depending on make/model), but my current one always runs for exactly 3 seconds too long and ever so slightly burns the popcorn.
It's not burned enough to throw it out, but it does give a noticeable "burnt popcorn" smell that kind of ruins my day.
So instead of pressing "popcorn" and doing something else, I have to stand there and watch it to hit 'cancel' in time.
That's just how microwave popcorn is. I just put the microwave on for 9 min or whatever large number is easy to start and wait until the popping slows to a second or two between pops. There's no way to have a perfect amount of time for all brands and packages of popcorn. Not to mention shrink-flation has made the time need to be shorter and different altitude changes how long it takes among other things. I have heard that some microwaves actually have been made with a microphone to listen for the time between pops, but I've never used one. But since they can't be adjusted for your preferences, I've heard they usually burn it anyway. It's always better to have it a little under popped than a little burnt IMHO. Once you do it a few times for a particular brand you'll find the right amount of time if you need to walk away.
I'm sure others have linked to Technology Connections' video on the subject below, but there are two general ways it works:
There is a humidity sensor in the microwave that will sense when food is done. In the case of popcorn, it senses when there's a burst of steam inside when the bag inflates enough to open the vent, and then given how long that took it calculates how big the bag of popcorn is and thus how long to keep running the microwave for. The other sensor cook buttons look for trends in humidity that have to do with other foods. The microwave will likely indicate that it has this feature with the word "Sensor" or similar branding on the control panel, and when you press the Popcorn button, it just starts running because it can figure out everything it needs to know for itself.
Small, cheap microwaves probably just use a timer. If it asks you if the bag of popcorn is small, medium or large at the beginning, it's just a timer and you should just go with the instructions on the bag instead.
It's a damn shame that we haven't built a microwave that actually listens to the pops and stops when the pops slow, just like every bag of popcorn instructs you to do. We've got gun shot detectors; you'd think we could build a chip to analyze popping popcorn.
A peak detector that resets a timer is within the realm of possibility, maybe combine it with the moisture sensor so that you start listening for the pops to slow down after you detect the burst of steam.
Granted that this isn't microwave related, but it's definitely popcorn related. Have you ever heard of a popcorn cannon? They're designed to even be able to pop regular corn right off the cob...
I've got that and a whirly pop. The whirly pop does better popcorn, but all I have to do to clean the air popper is shake it upside down. So we run about a cup of kernels through the air popper every night.
I always thought it was weird that they don't just stuff a cheapo little microphone in against an interior panel and write a couple lines of code, when it detects 3 really loud sounds within 1 second disable the timer, and when it detects a sound after a 2 second gap, turn off if no new sound detected within 2 seconds