I have an ancient microwave oven (my mom bought it in 1988!) and after it burned-to-a-crisp several bags of microwave popcorn, I got to thinking that maybe it was time to replace the old guy. However, since I only use it for making popcorn, I then thought about whether I should instead get an air-popper. This got me wonder: which uses more energy, popping popcorn in an air popper or a microwave?
Just figure out how much time each takes, and multiply by the watt rating.
That would give you an upper limit for each unit, sure, but they could use less.
I just cook it in a pot.
The power rating is basically theWatt-hours (W*h) (at maximum) so you could divide your total minutes by 60 then multiply by the watt rating to calculate the energy consumption.
The power ratings seem to favor the popcorn popper by far,a quick google search tells me that it is around 250-300W while a microwave can be 600-1500W.
Also, the popcorn popper is simple, you only plug it in when you use it, a microwave is usually plugged in all the time, has lights, a clock, a revolving platter, etc.
microwave popcorn doesn’t give the yield of an airpopper.
with an airpopper, if the kernels are hydrated you can get 100% most of the time with no burns. you might get some barely popped kernels but they won’t fly if they don’t pop.
airpopper is compact. used ones for a few to 10 dollars at thrift stores.
Assuming the amount of energy required to pop each kernel is approximately the same, regardless of process (although I’m conscious that heating the kernel by conduction from hot air may be more or less effective than heating it radiantly and directly, I think this is a fairly safe assumption - as in either case, sufficient heat has to be delivered as to melt the starch and raise the internal pressure enough to burst the grain)…
A hot air popper must be less efficient - as there is conspicuously more waste heat produced.
With a hot air popper, a constant stream of very hot air is emitted and lost, and the chamber and other parts of the machine are heated, which heat is also lost as the device cools after cooking.
A microwave does generate some waste heat - there’s a fan that cools the microwave emitter, I think, but throughout the cooking process in a microwave, the popcorn is about the only thing that gets hot. If the microwave oven is consuming more energy per unit of popcorn, where is it going?
ETA: are we including the energy used in preparing, packaging and distributing the popcorn for microwave popping?
I got a whirley-pop. It’s brilliant, pops faster and more reliably than a pot, and is way easier to clean.
Your popcorn burned in the microwave because the oven was not heating evenly or you cooked it too long.
Both an air popper and a MW take about the same wattage input now. In fact, some newer MW’s take even less than an air popper. Both take about 2-3 minutes to perform the task on a normal 1/3 cup of corn input. So the energy cost is about the same and very low due to the short cooking span. However, an air popper costs much less. A MW is more versatile, but if all you do is pop corn anyway, get the air popper. Of course, you can only use dry corn in the air popper.
And is there anything special about microwave popcorn? I just spray a bit of oil into a glass (Pyrex) bowl with a lid, pour in a bit of plain popcorn, and microwave it until the popping stops. Then give it another spray of oil and add sugar and salt. That gives perfectly good results and seems far cheaper than those little bags.
This is incorrect, from wiki…
Cite?
Every site I have found rates a microwave much higher than a popcorn popper.
here hereand here
If the cooking time and amount of popcorn is constant, how can you assume the microwave uses less energy?
OTOH, I think the OP is a tad unusual in using the microwave ONLY for making popcorn - what, you never even warm up a beverage or a bread item in it? I’d probably eat even less fresh vegetables than I do if I couldn’t just put some butter, salt and pepper on them, maybe add a tiny amount of water, cover them and nuke them for a minute or two to get a reasonable facsimile of steamed vegetables.
For most people, the popper doesn’t replace the microwave, and the total cost of having an extra special-purpose appliance has to be taken into account.
Sorry, which part of your Wiki quote disagrees with which part of something I said? It looks to me as though there’s significant agreement. I wasn’t very precise or exhaustive, but I wasn’t trying to be.
Furthermore, the quote says a microwave is 60 something percent efficient. Does a hot air popper achieve anything like this? It seems unlikely as the hot air passes over the kernels once, then exits the machine, still very hot.
Anecdotally, I have a very small kitchen - Running my hot air popper for fie to ten minutes makes the whole room uncomfortably warm. Running my microwave oven for a similar duration does not. What other explanation could there be? If my microwave is wasting as much energy as my hot air popper, where is it going?
Is it that straightforward? Like Sunspace says, that’s fine for a maximum, but would it really use that much in practice? And like Sparky812 says, a microwave is a more complicated machine–would all that energy go into popping corn?
Zombywoof, this is a good point, but then I’d have to learn patience. With an air popper I can start it going and read twitter until it’s done. With a pot I have to pay attention and stuff. 
Johnpost, that’s pretty much my POV, too. It pops more kernels and is a cheaper device, though microwaves are pretty cheap these days.
Mangetout, these are my questions as well. It seems like an air-popper could be less efficient, but then a microwave pulls a lot of energy, too, and may be inefficient with heat in other ways (like you mentioned, the fan), soooo…?
Cheesesteak, a whirly-pop does look like fun, but it doesn’t look easy to clean. Certainly not easier than just a pot. Plus I’d have to find someplace to store that thing. It’s bigger than an air-popper and I live in an NYC apartment. Then again, if I got rid of my old microwave I could just store it in the same space 
No, my microwave did–it’s old and faulty. What used to be the perfect length of time for a bag of popcorn is now the perfect length of time to blacken a golf-ball-sized chunk of corn while leaving about 25-33% of the kernels in the bag unpopped.
Makes sense to me–and the packaging and lack of control of the ingredients added to microwave popcorn always bugs me, so that’s an added bonus.
Exactly!Well, except for the microwave part. I’m trying to be more health conscious so this is what I was thinking, but why buy a microwave if all I’m going to use it for is popcorn, which I only eat maybe once or twice a month.
But would time and amount be constant? Also, an air-popper will pop most if not all the kernels, a microwave never does–whether it’s my ancient one or anyone else’s, in my experience, anyway.
I have a gas stove that seems easier and faster to use–at least, compared to a microwave that I’m worried could explode at any moment. 
Plus when butter splatters in the microwave it’s a pain to clean. Also, to be safe, I asked my wife about this and she agreed, she finds herself using the coffee maker to make hot water for tea or just boiling water on the stove. Plus, we have a toaster oven for heating food up. So, I guess we’re not “most people” (which we already knew, really).
This is my original question, pretty much.
This is a good question. Perhaps Cecil could take this on?
Regardless, I appreciate all the answers you guys have given me. I’ll talk it over with my wife, but I think we’ll not be replacing the microwave. Whether we start making popcorn on the stove (via a pot or a whirly-pop) or in an air-popper, I don’t know yet. However, this thread has given me a lot more information to consider so I’m thankful for everyone’s replies. If anyone has any more info to add, please add it!
Thanks, everyone!
Basically, yes. Assuming the nameplate rating is accurate, this will give you the total watt-hours each device uses to pop the corn. All inefficiencies are automatically taken into account. A more accurate method would be to use something like a Kill-A-Watt meter, and actually measure the energy consumption of each device, and then multiply by the time each takes.
BTW, Microwaves don’t really have variable power. They always emit 100% of their design power. To achieve lower power, they use on-off cycling, so that the tube is turned on and off for a variable amount of time. So, if you pop your corn at 100% power, you are using the rated power of the microwave.
Consider if considering energy usage is even practical. A 1000 watt microwave, which is on the more powerful end, uses 1kW of power. 1 kW power use cost about $0.10-$0.20 per hour. With that microwave the cook time should be under 4 minutes.
So 15 bags of popcorn cost 10 to 20 cents worth of power with this microwave or somewhere about a penny’s worth of energy a bag.
Now if you are in a off the grid situation that may change quite a bit.
First of all, I didn’t say it disagreed, I said your statements were incorrect.
Secondly, this is the SDMB, statements such as …
are all factually incorrect.
Anecdotes are not a substitute for fact, although if you are running your popcorn popper for 5 to 10 minutes, then in your case, a microwave probably is more efficient than your popcorn maker as most units take from 2-5 minutes.
Yes it does, and there is a simple “other” explanation, it just doesn’t dissipate it into the air as fast. Alot of it is stored in the magnetron tube, lamps, circuitry, heat sinks, AC transformer, etc… and dissipated over time.
Yes, exactly like the microwave … and the popcorn for that matter.
Furthermore, electric heating elements are known to be extremely efficient at generating heat. Your popcorn popper has a small element and a small cyclone fan which consume much less energy than a microwave and all it’s bells and whisles.
Adding to my above, if energy usage is considered from a environmental standpoint, the total energy of the system has to be considered, including the container, bag, oils used, shipping and also the manufacture of the microwave or popper.
I have a 1000W microwave and a 250W air popper. Both make approximately the same amount of popcorn in roughly 5 minutes. Plus, there’s no oil or salt in the air popped corn. Win for the air popper. YMMV.
Come on. You said my statements were incorrect, then said “from wiki…”. I’m assuming the Wikipedia quotation was not just a nonsequitur, so what else could you have meant other than that the two things were at odds?
I’ll concede that the last of the three statements is useless. The first, I’ll deal with in a moment, but what’s your problem with the middle (graped) one?
Let’s take a look back at your quotation from Wikipedia…
Looks like it’s in agreement with what I said. Is Wikipedia factually incorrect too?
Thank you for pointing out what I thought I made obvious when I labelled the anecdotal observation as such. It was not intended to be more than contextual discussion of where inefficiencies may be overlooked.
Fair enough (and as noted above, this point is conceded).
Not exactly like the microwave. The air popper heats by conduction and as a result, heat is inevitably added to parts of the machine itself. Of course, bits of the microwave are warming up in operation, but not because they’re being heated by the cooking element.
Not in dispute. I know that resistive heating elements are very efficient, but you failed to address the efficiency of transfer of heat from the hot air to the corn kernels.