On the farm · From Farmer Bob
How popcorn gets cleaned
Popcorn comes out of the field dirty. Before it goes in a bag, every kernel I sell gets vacuumed, sized, sorted by weight and photographed. I'm a first-generation farmer, so I had to learn how all of this works, and I think it's the coolest technology in the whole business. Come see it.
Non-GMO popcorn · Seed to Store™ · One Farmer, One Field™
Farmer Bob at Polansky Seed in Belleville, Kansas. 9 minutes.
By the numbers
Cleanout and cleaning speed are from the run in the video. Every harvest is a little different.
The short answer
Popcorn is cleaned dry, after it has been harvested and dried down to popping moisture. It moves through four kinds of machines: air to pull off dust and chaff, screens to take out anything bigger or smaller than a kernel, gravity tables to take out kernels that are too light or too heavy, and optical sorters that photograph every kernel and kick out the cracked, chipped and off-color ones with a puff of air. What's left gets weighed and bagged.
- Who does it: my popcorn is cleaned at Polansky Seed in Belleville, Kansas, a company that cleans seed for a living.
- How much comes out: on the run in the video I hauled in four truckloads of 1,000 bushels each. About 85% of it came back as finished popcorn. The rest feeds my pigs.
- Why it matters: a kernel with a cracked hull can't hold pressure, so it won't pop. Clean, whole kernels are what give you a full bowl.
Step by step
From the truck to the bag
Here is what happens to a load of my popcorn at Polansky Seed, in order. Each step has a button that starts the video right at that part.
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Step 1
It gets unloaded gently
The truck parks over a vibrating conveyor set down in the floor. The popcorn shakes its way forward, rides up a leg and drops into a storage bin. Nothing gets thrown or dropped hard. That matters, because a kernel with a cracked hull will never pop.
Watch this part · 0:15 -
Step 2
Air pulls off the dust
From the first step to the last, the whole plant is under suction. Two huge fans, one 100 horsepower and one 150, push air in and pull it back out through tubes that run to every machine. Any dust that comes loose gets sucked away.
Watch this part · 1:52 -
Step 3
Screens sort it by size
Next come the grain cleaners. They size the popcorn and take out the big bulky stuff and the very small stuff, like a bit of dirt or a piece of a broken kernel. More comes out here than at any other step.
Watch this part · 2:32 -
Step 4
Gravity tables sort it by weight
A gravity table uses vibration and air to get the kernels moving and spread them out by weight. The very light ones probably won't pop well. The very heavy ones could be a stone the same size as a kernel. Both go.
Watch this part · 4:04 -
Step 5
The pretty good goes around again
This happens in waves. Anything that came out pretty good but not great gets run through again, so only the best moves on.
Watch this part · 5:38 -
Step 6
Cameras look at every kernel
This is my favorite part. The popcorn falls through an optical sorter faster than your eye can follow. Cameras photograph each kernel from two sides, so the whole kernel is visible. Anything broken, misshapen or outside our color profile gets kicked out of the stream by a little puff of air.
Watch this part · 5:46 -
Step 7
It gets weighed and bagged
What's left is super clean popcorn. It is weighed into 50 pound bags and trucked back to my warehouse, where it gets packed into the bags you order.
Watch this part · 6:53
Why I care about this
Nobody handed me a manual
I didn't grow up farming. Everything on this page is something I had to go learn, and I still get a kick out of it.
I put a lot of effort into growing good popcorn. But it grows out in a field, and a field is full of things that aren't popcorn: dirt, dust, ladybugs, bits of plant. So after I harvest it and dry it down, it has to be cleaned.
I used to clean it myself with a very small cleaner. Then I started hauling it to Polansky Seed in Belleville, Kansas. What they do is faster and far better than anything I could do at home, and they have helped my quality more than I can say. I send them my best popcorn, and they pull the best out of that.
As soon as you crack that outer shell, the popcorn's done.
My standards are high because I'm a customer too. I eat my popcorn every single day. I don't just grow it, I love it, and I'll talk about how it's made all day long.
What gets taken out
What comes out, and what catches it
About 15% of what I hauled in on that run never made it into a bag. This is what it was.
| What comes out | What catches it | Why it has to go |
|---|---|---|
| Dust and chaff | Air | It's field dust. Nobody wants it in the bowl. |
| Dirt and bulky trash | Screens | Bigger or smaller than a popcorn kernel. |
| Pieces of broken kernels | Screens | Too small, and they will never pop. |
| Lightweight kernels | Gravity table | A kernel that is too light probably won't pop well. |
| Stones | Gravity table | Same size as a kernel, but much heavier. |
| Cracked, chipped, misshapen or off-color kernels | Optical sorter | A cracked hull can't hold pressure, so the kernel won't pop. |
Nothing goes to waste
The rest goes to the pigs
So what happens to the popcorn that gets cleaned out? I feed it to my pigs. A kernel that is too small, too light, cracked or the wrong color is still perfectly good corn. It just isn't good enough to sell you.
My wife wanted pigs, so we got pigs. That was about ten years ago. They're Large Blacks, an old English heritage breed with big floppy ears and an easy temperament. I call them my popcorn pigs.
Sometimes they even get it popped. Nothing I grow gets wasted.
My favorite part is when they have piglets. They remind me of little miniature elephants.
My Large Blacks working through a pile of popped popcorn. Press play to meet the herd, from my series American Harvest.
Quick answers
Popcorn cleaning, in short
How is popcorn cleaned?
Popcorn is cleaned dry, after it has been harvested and dried. Air pulls off dust and chaff, screens take out anything bigger or smaller than a kernel, gravity tables take out kernels that are too light or too heavy, and optical sorters photograph every kernel and reject the cracked, chipped and off-color ones.
Why does popcorn need to be cleaned?
Popcorn grows in a field, so it comes in with dirt, dust, bugs and bits of plant. It also comes in with kernels that are cracked, undersized or too light to pop. Cleaning takes all of that out, so what ends up in the bag is whole kernels that pop.
How much popcorn is lost in cleaning?
About 15% on the run in my video. I hauled in four truckloads of 1,000 bushels each, and about 85% of it came back as finished popcorn. What gets cleaned out isn't wasted. I feed it to my pigs.
What happens to the popcorn that gets cleaned out?
I feed it to my pigs. The kernels that are too small, too light, cracked or off-color are still good corn. They just aren't good enough to sell, so nothing goes to waste.
How much does a bushel of popcorn weigh?
A bushel of my popcorn weighs about 63 pounds. That number is called test weight. A bushel of field corn typically weighs 56 pounds, so popcorn is a good deal denser.
How much popcorn is in a truckload?
Each of my trucks holds 1,000 bushels. At a test weight of about 63 pounds per bushel, that is about 63,000 pounds of popcorn in one load.
How many popcorn seeds are planted per acre?
I plant 30,000 seeds per acre. Each seed grows one plant, and each plant produces one ear of popcorn.
What does an optical sorter do to popcorn?
An optical sorter drops the popcorn past cameras that photograph each kernel from two sides. Any kernel that is broken, misshapen or the wrong color gets knocked out of the stream by a small puff of air.
What does a gravity table do?
A gravity table uses vibration and air to separate kernels by weight. Kernels that are too light usually won't pop well, and anything too heavy could be a stone the same size as a kernel. Both get removed.
Is popcorn washed with water?
No. Popcorn is cleaned with air, screens, vibration and cameras. A kernel pops because of the moisture sealed inside it, so getting it wet would work against you.
Why do cracked kernels not pop?
A kernel pops when the moisture inside turns to steam and builds pressure against the hull. If the hull is cracked the steam leaks out and the kernel never pops. That is why popcorn has to be handled gently and why cracked kernels are sorted out.
Who cleans Princeton Popcorn?
Polansky Seed in Belleville, Kansas. I grow, harvest and dry the popcorn on my farm in Princeton, Kansas, then truck it to Polansky Seed to be cleaned.
Taste what clean popcorn pops like
I grow three kinds of popcorn on my farm in Princeton, Kansas, and all of it goes through this process. Not sure which one to get? The Popcorn Picker sorts it out in a minute.
More from the farm: Meet Farmer Bob · Non-GMO testing · Subscribe on YouTube