
We Tried to Preserve a Strawberry Forever. Things Got…Ugly
Season 7 Episode 15 | 8m 5sVideo has Closed Captions
See what happens when we try to make a strawberry last forever.
You’ve heard of the epoxy hot dog, but how about the epoxy strawberry? On this week’s episode we’re going to try to make a strawberry last forever.
Problems playing video? | Closed Captioning Feedback
Problems playing video? | Closed Captioning Feedback

We Tried to Preserve a Strawberry Forever. Things Got…Ugly
Season 7 Episode 15 | 8m 5sVideo has Closed Captions
You’ve heard of the epoxy hot dog, but how about the epoxy strawberry? On this week’s episode we’re going to try to make a strawberry last forever.
Problems playing video? | Closed Captioning Feedback
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Learn Moreabout PBS online sponsorship- You've seen the epoxy hot dog.
It was preserved in pretty much perfect condition for at least nine months.
Thing is, a hotdog is loaded with preservatives.
So I'm actually not all that impressed that it's lasting basically forever.
But what if epoxied something with no preservatives like a strawberry.
Would it still look the same, X months later?
Could I make this last forever?
(drum roll) Epoxying is the most internet way of preserving something.
♪ Welcome to the internet ♪ But we're a chemistry channel so we wanted to try a bunch of other methods, too.
It turns out that there are hundreds of ways to preserve food beyond just sticking it in the fridge or freezer.
You're probably most familiar with chemical methods because of ingredients labels.
But before we had modern chemical preservatives, our ancestors got real creative with preserving food.
They smoked it, dried it, fermented it, pickled it, even buried it underground.
And if they hadn't, most of that food would have spoiled really fast.
Because chemicals inside food react with air or each other, and degrade.
Also we're surrounded by billions of cells of bacteria, yeast, and molds that are psyched to eat that food.
Take for example, the mold penicillium expansum.
It loves eating fruit.
And as it does, it starts secreting patulin which reacts with sulfhydryl groups on proteins within fruit cells, killing them and making the fruit rot.
So to preserve food, we need to stop the chemical reactions that cause it to degrade and keep microbes from turning it into mush.
There are so many ways to do that.
And if I was gonna test even a few of them, I needed help.
- All right, Pat Sayjack, spin it.
Give it a quick bumper, give it another one.
- We're spinning this giant wheel to split up the different preservation methods between the two of us.
The methods we chose fell into three general categories, adding one or more chemicals, removing water and removing air.
We decided to spray a strawberry with hairspray, cover one with floor sealer, pickle a strawberry, put one in sodium hydroxide, put one in embalming fluid, a.k.a formaldehyde, put a strawberry in salt, put one in honey, dry one in the oven, injecting a strawberry with brine and of course, seal one very lucky Berry in epoxy.
Once George and I had set up our experiments, we just let them sit for a couple months.
Actually, except for the formaldehyde strawberry.
Formaldehyde's pretty nasty stuff.
So I called up a friend who works with it in the lab.
I have a kind of weird question for you.
- Go for it.
- How do you feel about embalming a strawberry for me?
- I have been waiting my entire life for you to ask me that question.
- Okay, the results.
Two months later, the control strawberries were gross.
That was expected, but there were a lot of other things that were totally surprising.
Are you ready to see some disgusting stuff?
- No.
Oh God!
That's like dead fish.
- What this is is the floor sealer one.
- Really?
- It looks like if you just took a strawberry, flattened it down and then grew a bunch of mold on it, but it still has more of a structure than the control does.
Do you wanna know what my biggest surprise was?
- Yes.
- That hairspray did really well.
It just looked like a strawberry that it kind of lost its color.
It's pretty amazing.
Floor sealer and hairspray are designed to hold stuff in place and create a lacquer-type barrier.
But the floor sealer seemed to make the strawberry just as gross as if I'd done nothing to it.
Maybe grosser?
The main ingredient listed is partially fluorinated alcohol, which is very vague and covers a lot of different polymers that have flourine atoms.
It's listed as, "Providing an invisible barrier, resistant to stains, while allowing the surface to properly breathe."
It's the surface breathing that seems like an issue because that means that stuff can still get into the strawberry.
Hairspray, though, worked surprisingly well.
Hairspray is made up of polymers like PVP and PVAc which create a pretty tough film.
Apparently tough enough to make the strawberry still look like a strawberry months later.
Pickling with white vinegar, water, salt and sugar seemed to preserve a strawberry pretty perfectly as did sodium hydroxide, also known as lye.
And injecting it with salt solution, which is really just pickling it from the inside out.
And no surprise here, but formaldehyde worked like a charm.
- So this is what bodies are embalmed with.
- People use formaldehyde sometimes, but paraformaldehyde has become, I think more standard.
- Look at the control.
What is growing on that?
- I have no idea.
- That is so disgusting.
- This was done in a lab and I wonder what's circulating in the lab because it's not what was circulating in my house or your house.
Formaldehyde works by bonding together a bunch of different molecules and cells like DNA and proteins.
So much so, that microbes can't break them down and eat them.
You lose a bit of color, but the structure of the fruit looks the same.
And I can't see any microbial growth.
So when it comes to adding chemicals, as long as that chemical can inhibit microbial life, it can preserve a strawberry.
If you want to actually eat the strawberry though, you have to be careful that whatever chemical you're adding doesn't hurt you.
So yeah, don't eat formaldehyde or sodium hydroxide or hairspray preserved strawberries.
All living things, including the microbes on your food, need water.
Because almost all of the chemical reactions that allow them to survive, happen in water.
So take away water from microbes and you stop them from spoiling your food.
You might be wondering why putting a strawberry in honey is in this category.
Honey is only about 30% water and other stuff, but it's 70% sugars like glucose, fructose and maltose.
Sugars have all of these hydroxyl groups attached to them, which attract water molecules.
With sugars holding onto these water molecules, the microbes that need water, like bacteria, can't grow.
So your strawberry might look a little shriveled up from the water inside of it, moving out into the honey, but otherwise, not so bad.
The next least gross one is honey.
It is hard to see.
It's not gross looking at all, I mean, nothing seems to have grown in there.
- Okay, I'll go.
This is the only one that's a surprise.
It has been encased in salt, except I'm not sure I can actually- - Just smash it against a wall.
- Okay, here we go.
Look at that.
Who knows what that is?
- It must've just had enough stuff like on the strawberry to begin with.
It could still grow.
It hit a point where it was like, that's it.
That's not a lot of growth for that much time.
- I actually forgot, I have one more.
These are the ones that I put in the oven.
- So they're small.
- Well, you'd think, but they're normal sized.
They came out of the oven looking like this and they have not changed.
- Okay, last, but definitely not least our au naturel version of the epoxy hot dog, the epoxy strawberry.
So within a few days it was less red, probably a month in, it looked like this.
It's interesting that it's lost its color, but the color didn't visibly go anywhere else.
There's not even a faint pink or anything.
This is just- - That's like kind of creepy.
- It's like a ghost ship, but a strawberry or something.
The trick behind this preservation method is removing oxygen.
Although there are some microbes that live and even thrive without oxygen.
Most living things need oxygen to metabolize their food.
Without oxygen, the organism can't eat.
So it eventually dies.
If this were a competition, I think I win in terms of variety.
- I think I have more well-preserved strawberries here than you do.
But you have more entertaining strawberries.


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