You have popcorn and it won't pop. Your life is RUINED. At least the duration of your life during movie night is. Today, how to test and fix popcorn that won't pop.
You don't need a lot of cobs to give you a lot of popcorn. 7 very small cobs gave me almost 2 cups of kernels.
First of all, I realize there are all of 14 people in the world that grow their own popcorn. Me, Orville Redenbacher and all of his descendants.
However, this doesn't just apply to popcorn you've grown, it also applies to old popcorn you've found in your cupboard that's being particularly stubborn about exploding into something edible.
So let's talk about that.
Table of Contents
The 2 reasons your popcorn won't pop.
- If you can dent the kernel with your nail it's still way too wet to pop.
- If the kernel is very hard and can't be dented but doesn't pop, it probably needs moisture added into it.
You need to either dry it out more or put it in a jar and add a bit of water. It's really as basic as that.
WHY exactly does popcorn pop?
What makes popcorn pop is having a specific amount of moisture inside it. Popcorn might seem like it's completely dry but the kernel holds a tiny bit of water inside the dry starchy outer layer. For a kernel to properly pop it needs to be at 14% moisture. When the small amount of moisture in the centre of the kernel heats up, it expands and creates pressure on the starchy dry shell.
Eventually the shell says I CAN'T TAKE THIS ANYMORE and it bursts. The starch inside flies out with an explosion and the whole kernel turns inside out. And then you have popcorn.
If the kernels are either above 14% moisture or below it won't pop properly.
You can see examples of different moisture levels below. They were each popped in hot oil in a cast iron pan on the stove.
You can also use this microwave method I outline here to make popcorn.
From left to right:
- Newly opened jar of Orville Redenbacher popcorn kernels. Perfect moisture content of 14%. Big, fluffy. 100% popped.
- 2 year old jar of Orville Redenbacher popcorn kernels. Low moisture content of 10%. Smaller, more dense. 100% popped.
- Homegrown popcorn. Low moisture content of 10%. Small, dense kernels. 78% popped.
- Homegrown popcorn. High moisture content of 20%. No truly popped kernels.
That's all fine and dandy but how do you know what moisture content your popcorn is??
3 ways to test the moisture in popcorn
The first time I grew popcorn I didn't know ANY of this. I took a cob that I'd let dry for approximately a hundred million years and the kernels didn't pop. They just burned and looked like little blackened molars that had been shaken out of the head of a meth addict. Why didn't it pop? Because it had almost no moisture in it.
1. Grinding and weighing.
The most detailed, scientific, mathematic article about making popping corn ever written, courtesy of Mother Earth News is where I started. The article gives detailed instructions on how to figure out the moisture content corn by grinding it up, weighing it and then baking it in the oven for a couple of hours to bake out any moisture in it. Then of course, you weigh it again and the difference between the pre-baked corn and the post-baked corn will tell you how much moisture you lost (and therefore how much moisture was in the corn to begin with).
This test revealed that my corn (in this case it was Glass Gem Corn) was about 4% moisture. Way too low. To remedy this, the article includes a handy math equation that lets you know how much to add to bring your corn up to the recommended 14%.
So I added the amount of water I needed to my popcorn and waited a day for it to absorb.
Then I tried popping it again and 2 kernels popped! So basically a total success if you're only planning on popping corn for 14 Ladybugs and an imaginary rabbit.
You can continue on these lines of adding a tiny bit of water until your popcorn pops.
2. Moisture Meter
A moisture meter is a common tool you can get at your local hardware store for about $80. The cheapest versions I've found have been on Amazon for $40 Canadian and it's where I got mine. The meter is meant for measuring the moisture content of wood and drywall. But I found out it works on popcorn too.
The meter has two very sharp pins on it. These pins are stuck into the material you are measuring the moisture of.
I figured it it worked for wood it would work for popcorn and it did but it doesn't give a completely accurate reading.
BUT THAT'S O.K.! You don't need a 100% accurate reading, you just need the tool so you can get a baseline reading.
Stick each prong onto a kernel of corn. Then place your finger across both of them and push down slightly. This will get you a relatively accurate reading.
The brand new, perfect Orville Redenbacher gave me a reading of 11.2% moisture. Even though it isn't giving a reading of 14%, I KNOW that the folks at Redenbacher have it right so all I want to use this number as my baseline number.
I want MY kernels of popcorn to measure the same: 11.2%.
They do not, lol.
I had some cobs that weren't dry enough yet and some that were over dried. The wet ones got dried some more and the dry ones were rehydrated with that adding water trick. More on that after method 3.
3. Hygrometers
A hygrometer is a little disk that tells you what the humidity is. They're small enough that you can drop them in a mason jar.
They're $15 for 4 in the US or $20 for 4 in Canada.
If you do any kind of vegetable curing or storage you need these.
To use a hygrometer for testing the moisture level of popcorn, drop one in a jar filled with popcorn. Like with the moisture meter, you need a baseline so drop one in a jar with popcorn you know pops well as well.
The hygrometers confirm that my homegrown Dakota Black popcorn is way drier than the Orville Redenbacher popcorn.
How do you fix popcorn that won't pop?
You soak it in water.
Whether it's popcorn you bought ages ago at the store or popcorn you've grown yourself, chances are it's too dry and doesn't have the moisture it needs to riotously explode.
Add a teaspoon of water to a mason jar filled with popcorn and shake it so the water is evenly dispersed among the kernels and leave it for a day with a lid on it.
Test the popcorn.
To test the popcorn use the moisture meter or the hygrometer. If after a day the popcorn is still too dry, add another teaspoon of water and let it sit for another day. If the kernels are now too WET, just pour out the kernels onto a plate for a couple of hours to dry out a bit.
When you think the kernels are about right - take 5 or so of them and try to pop them.
By the way, if you're adding water to a jar to bring your popcorn up to moisture just add a little at a time. Not too much. And don't maybe forget about it in the cupboard.
Upon seeing these my immediate thought was, soooooo ... if I don't digest a hunk of popcorn and it sits in my watery stomach for a few days will it root, embed itself into my nutrient rich belly lining and grow a stalk of corn which will eventually shoot out of my mouth as I sleep one night?
Or no? Will that maybe not happen.
Probably no. But just to be safe, I should probably redirect my attention to growing potato chips.
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Poorly popped pop corn brought me to this page and I laughed so much at this article that I want to know more things! Thank you for the info and the laugh :)
Excellent! My condolences on your inefficient popcorn. ~ karen!
Hi karen! my daughters talking about the moisture levels of corn for a science project, and this really helped her out. Thank you! :)
That's great! Happy to help. I know the information is hard to find! ~ karen!
Very excellent treatment. I came here, of course, because my quart mason jar of store bought yellow popcorn (1/2 full now) didn't pop yesterday. I was using my old trusty electric popper. ~25% didn't pop at all, the ones that did pop made startlingly loud popping noises and pretty smallish popped kernels. I figured looking this up I'd find remedies to rejuvenate my stash and recipes for using hopeless stash. I've found both, but this site is by far the best in terms of what I can do to fix what I've got. I have a moisture meter, no hygrometers (figure to shop them). Now, what I have I did add some water to a month or two ago, but didn't measure. I will try the fingernail test to see if the kernels seem not firm. I figure maybe it's too much moisture here because of the super loud popping I had. It sounded like a gun, for crying out loud!
Good luck Dan! ~ karen
Wow...you're serious about buying all these hydrometer or hygrometer gizmos just to have some popcorn, which turns a hassle-free snack into something a little more post-covid hassled. Think I'll just shell out (or "kernel" out---sorry) the extra ruble or two and just buy Orville's brand. Don't mind supporting the guy, looks like a genial-enough geezer. Did enjoy your writing style, though. Thanks.
Oh my...trying to pop the corn I have left in my store for over 1year...and it was coming out like some burnt stones for idols...I angrily boiled water and poured it inside...with your post,I went to dry it please will it ever pop?
I'm actually not sure Ogunsola! Just let it dry for a few days and then try popping 2 or 3 kernels. It's possible! ~ karen
thank you for your article. Popping Great Value corn on the stove and it quit popping. You explain so well.
Also the person who built our house did something wrong and we have too much moisture in the winter time. Condensation on all the windows, ect. So we run dehumidifiers all winter. We've bought things to tell us the humidity in our house, they don't work or break. Now we know what to get to measure humidity! Thank you!
Amazing: blog, personality, writing style and sense of humor.
Plus - of course - useful advices and observations.
By the way - haven't you been thinking about writing a book?
Greetings from…Poland.
I so enjoy your writing style!
This is why I <3 you and your blog. The amount of Type A, creativity and practicality you bring to life is amazing and inspiring. Oh and the hilarity is a plus, too!
I am surprised that I didn't see this info back in2016... but as an avid popcorn fan (one of my kids even earned the name Popcorn when she used to bring popcorn to school for snack!), I am so happy to read and learn about troubleshooting.
Hi Melissa! I rewrote the majority of this post with all new information, so you may have seen it but it's much updated after 4 years. Older and wiser and all that, lol. ~ karen!
Hahaha, hygrometer link says they are now $97.53 for 4!!!! Inflation and probably Covid as everyone blames Covid for any kind of price hike. Ah well, should've bought them in 2016!
Amazon sometimes does that. If a product is sold out or not available they show you one that's an insane price. If you search hygrometer on the Amazon search a more reasonably priced one will come up. :) ~ karen!
Thanks, I did and ordered some! Have so many uses for these...
I have been so utterly stressed out lately and then I read your post. I laughed so hard then came the hilarious replies that made it all even better. Thank you I needed that so badly.
I found your post because I got a multi variety set of heirloom popping corn. I tried a new type tonight and it didn't pop. Mildly disappointing but I got it off amazon not the original makers website so who knows how old it is. I am enjoying the set so far and now have preferences haha. Apparently I don't care for sweet varieties and I love the tiny kernels with tiny little pops vs the extra large kinds. Also its cool to be able to make exactly as much as you want and to completely control the seasonings. So don't give up on it just yet!
lol this is very funny,
i was searching on how to find non popping kernels, so i can roast them..
you know these popcorns at the end which pops not?. and then while you eating popcorn and get one or two in your mouth you can feel the taste of roasted kernels mixed with salt taste soooo good,
and then i jumped into your post hilarious,,, here in africa senegal we have no popcorn kernels farm or anything we get these imported, only sweetcorn yeah we do have that and they are rare by seasons and not much, we got to know the people or farmers who get those and have them requested,,
don't get me wrong lol i love popping popcorn but as for a change i thought i can make a big batch of roasted popcorn kernels !!
thanks Karen for this lovely post
You're welcome Sami! I actually have a friend from Senegal (around Dakar ... I have a feeling it's Yoff). She lives in Canada now but was born and raised in Senegal. Good luck on your quest for perfectly unpopped popcorn! ~ karen
After a small popcorn mishap that I would rather not discuss, I came across this article, and I have concluded that you and I might be genetically related. If I ever attempted this, this is EXACTLY how it would go.
Like, the initial stage of ridiculous precision (weighing, baking, weighing again, determining exact moisture content). Then, when it doesn't immediately work out perfectly, giving up completely and doing whatever random impulsive thing occurs to you (dumping water, letting it sit for days). Then, the absurdly messed-up result, followed by hilarious jokes about the absurdly messed up result at the expense of Whole Foods shoppers (who you should definitely not be making fun of while you are GROWING AND POPPING YOUR OWN POPCORN).
I seriously identified with this process on a deep level.
Welcome to the family. ~ karen!