I know that you've all done it. I'll admit it. I've done it too. My sister Jenna was the best at it. She once cooked popcorn and set the timer for 3 minutes and it started to burn after 2. The entire family ran to the kitchen to see what was going on and Jenna was there staring at this smoking microwave and not doing anything. I think I turned the microwave off. We asked her why she didn't do the same and she answered, "But the directions said 3 minutes!"
Yes, we have all burned something in the microwave and then had to deal with the stench of burnt food. Now the worst smell of all has to be burnt popcorn. I don't know why that is, but burnt popcorn smells like rancid cat urine with a liquid smoke scent.
Now, my friend burned something in her microwave yesterday and she asked me how she could get the scent out. The solution that Momma Gray taught me was to take some vinegar and baking soda and coat the walls with it and let it sit for a couple minutes. This should get rid of the smell off the walls, but the real stench resides on the fan and the vents.
So what can you do? I asked Google and Google told me this: cut up a lemon and put it in a bowl of water and nuke it for 6 minutes.
I found this site with a whole mess of other pundits on the subject and here are some other solutions I found.
*Oh my gosh, I think that I created the first taquito smoke bomb ever! And the smell was horrendous. I over cooked about six taquitos in the microwave (thanks to the dial deciding to go backwards). I used straight vinegar in a bowl, got it to the boiling point (about 5 minutes), then let it sit. I continued doing that for about an hour or so. The moisture from the boiling vinegar travels through the fan mechanism. The vinegar smell through the house will go way. No smell from microwave. Whewwww! (02/18/2008)
*Heat vanilla extract in a bowl in the microwave for approximately 35 seconds. Turn off microwave, and leave door closed for 12 hours. (05/11/2008)
*I have burnt my microwave while making popcorn, the smell stunk and the walls were so yellow! After reading lots about it on the internet on how to fix the issue, here are 4 steps that worked very well for me:
1) Add fresh coffee grounds to a bowl with water and boil it at least twice (will get most of the odor off).
2) Then "cook" cinnamon or something else you like the smell of (will help get rid of the smell in the vents).
3) Clean the yellow dirty walls with cotton pads & nail polish remover (I used acetone based, but they say the acetone free works too).
4) Repeat step 2 as often as you need to fully remove the popcorn smellI was about to consider buying a new microwave but gave it a chance trying this out and VOILA :) (02/12/2009)
Well, I hope that helps.