- Sometimes dishonest honey producers will cut their honey with other sources of sugar, things like beet syrup or corn syrup.

So we went out and bought 20 honeys from specialty stores, discount stores, farmers' markets.

And I ran these honeys through a gamut of tests to see if any of them were actually not honey.

And this one does not look like honey.

What are you putting in your tea?

What am I putting in my tea?

Things like rice syrup and corn syrup, and cane sugar have all been found in adulterated honeys.

And a recent report by the European Commission found that 46% of honeys imported into Europe were adulterated in some way.

That is a huge percentage.

Now, ideally, this kind of fraud would be found before it makes it to your store shelf.

But I wanted to see if I could use chemistry to reveal any honey fraud in some samples that I could acquire here in the United States.

So I went out and bought 15 honey samples, and I also had George buy and ship me five honey samples.

I also asked him to adulterate one of those samples with corn syrup so that there would be a control in my test, but I didn't know which one that was.

Insert footage of George.

- [George] These are five honeys purchased from five different producers, and I'm gonna adulterate two of them.

Alex thinks I'm adulterating only one of them, but I thought I'd just take things up a notch.

I'm definitely gonna adulterate this one because I already ate some of it.

Fill this up with corn syrup and mix it.

I'm gonna adulterate one of the bears.

You know what I should really do is, like, smear honey on the outside of all of these (laughs) so that Alex thinks I've manipulated every single one.

(George chuckles) Oh, I'm sorry, Alex.

I'm really sorry.

All right, that should find her.

- So I wanted to think of ways that I could test this honey at home.

And the first thing that I thought of was a crystallization test.

I know from candy making that corn syrup can interrupt the crystallization process.

So my thought was that if any of these honeys were adulterated with corn syrup, perhaps that would interfere with its ability to crystallize.

And I thought this test was going to be so easy.

I poured out some honey, I put them in the fridge, I put them in the freezer, I tried to microwave them.

I tried to add sucrose to try and get them to crystallize.

I tried to add fructose to get them to crystallize as a nucleation point.

Do something.

Despite the fact that whenever I bring honey home, it immediately starts to crystallize, I could not get it to happen in my tests.

(buzzer buzzes) So test one: totally not conclusive.

Told me nothing about whether or not any of these honeys were real or fraudulent.

So next I wanna measure the amount of sugar in each of these honeys.

I'm gonna do this using something called a Brix test.

And a Brix test is a measure of the amount of dissolved solids in a solution, which for honey means that one degree Brix is equal to one gram of sugar for 100 grams of solution.

Honeys can vary a little bit in their sugar concentration, but they should be somewhere between 70 and 88 degrees Brix.

And we're gonna measure that using a refractometer.

So the idea is that I'm gonna put a sample of honey on here, I'm gonna squish it down there, and then I'm gonna look through this at the light.

And there's a little scale inside, and it is measuring how much the light coming in is refracted when it goes through that sample.

And that is gonna tell us something about how much sugar is in that sample.

So the Brix testing was not super helpful.

All of the Brix measurements for all the honey samples were between 80 to 84 degrees Brix, which is right around where it should be.

The samples for corn syrup were around 77 degrees Brix, which makes sense for it.

And so it's hard to know, you know, if there was a honey here that should have been 82, but then it was mixed with corn syrup, then it came a little lower and was at 80, just inconclusive.

If something had come in at, like, 70, I would've thought, "Okay, that's probably not honey."

But not conclusive.

(buzzer buzzes) Now, I also remembered that honey fluoresces under a black light.

Most of the fluorescence is due to the fact that they have things like flavonoids and amino acids inside.

So I thought perhaps if I went and I looked at which ones fluoresce and which ones don't, that could tell me something.

Fortunately or unfortunately, all of the honey samples did fluoresce.

And because I don't have a spectroscope, I can't measure the exact fluorescence.

So this also was pretty inconclusive.

(buzzer buzzes) So it's time to try something different.

We're doing stable isotope analysis.

Now, I learned about this technique from a really cool episode of the podcast "Criminal" that was talking about fishing competition fraud.

Long story short, they were able to detect that the fish that were caught in a specific competition could not have grown up in that specific lake where the competition was taking place because the stable isotopes inside the otoliths, or the little ear rocks inside the fish, did not match the composition of that lake.

That is so cool!

That's so cool.

I'm obsessed with that chemistry story.

We can use stable isotope analysis to look for adulteration in honey samples, not because of where the honey is from, but because of photosynthesis.

So plants use photosynthesis to turn carbon dioxide and water into sugars, and there are different types of photosynthesis.

And the two we're gonna talk about today are C3 and C4 photosynthesis.

Well, bees make honey by going to flowers and collecting nectar.

That nectar contains sucrose.

They bring the nectar back to their nests, they mix it with some enzymes, they put it in the combs, and the enzymes break down that sucrose into fructose and glucose and do some other stuff and make it into honey.

The plants that bees typically collect nectar from, things like wildflowers and clovers, and trees, are typically C3 plants.

They use C3 photosynthesis.

However, things like corn use C4 photosynthesis.

The two types of photosynthesis differently incorporate carbon dioxide containing C-12 and C-13 isotopes.

C4 plants end up accumulating more carbon-13 in their sugars than C3 plants.

So if we look at the ratios in things like honey and corn syrup, they're gonna be different.

This is going to have more carbon-13 in it than this does.

So you can graph that out, and it looks something like this.

Over on the right side, you're gonna have plants that have more carbon-13; those are more likely to be our C4 plants.

And on the left side, you have plants that have less carbon-13; those are more likely to be our C3 plants.

Now, I understand that the number line here is negative.

It's okay.

It's just because the reference value that all of these are measured against in the field has a lot of carbon-13.

So I made some calls to people who do stable isotope analysis, and amazingly, Jennifer Cotton at CSU Northridge was willing to let me come in and bring some honey samples into the lab to test.

Okay, so Jennifer weighed out really tiny amounts of each of these samples, put them in a little tin cup, and then they first went into a combustion system.

This combusts them, right?

It's very hot; it's, like, almost 1,000 degrees Celsius.

It lights them on fire, and then it takes the gases that come from that and puts them into a gas chromatograph.

This separates out the gases by type, so we're able to look at just the CO2 when we then move it over to the mass spec.

So basically, you are running these CO2 isotope logs by a magnet at high speeds, and depending on whether or not that CO2 is made out of C-12 or C-13, it deflects a little bit differently with the magnet.

So what's happening right now is that this is measuring the different ratios of isotopologues that are hitting the detector, and it is giving us a ratio of carbon-13 to carbon-12.

Now, this is not a corrected number, but for many of these samples, the things we're getting are coming out to be like negative 25, negative 24, something around there.

That seems in the right range to be honey, and it will have some correction that happens to that later.

But for one of these samples, the numbers came up a little differently.

So for this sample, sample G, the number came up at negative 13.

That's the ratio of carbon-13 to carbon-12.

That looks suspiciously more like corn syrup than it does like honey.

I think we might have found honey fraud.

May I present to you our histogram of results?

Okay, remember when we're looking at these, we suspect that things that are C3 photosynthesis will be over on the left side of the graph, and things that are C4 photosynthesis will be over on the right side of our histogram.

And this shows up right here.

So this guy is cane sugar, and this is Karo syrup, and these come in at around minus 11.

Over here, these guys, the honey samples from either me or from George, most of them sort of center somewhere around minus 27.

We have two sort of suspect-looking ones from George right here.

These guys are a little lower than the rest of the honey samples, a little more towards the right.

These are around minus 23 and minus 22.

So those seem a little suspect.

Both of those seem like maybe George added a little bit of corn syrup to those to sort of move them out.

But this one, this is the one that when we saw in the lab, Jennifer was like, "That's not honey.

(laughs) That is likely corn syrup."

So this sample came in with a ratio of minus 14.47.

This value looks so much more like C4 photosynthesis, and this looks so much more like C3 photosynthesis.

So I don't think that this is 100% honey.

So the ingredients on the back say wildflower honey.

It is a product of Turkey, which is an area where adulterated honey has been seen lately.

Now here's the thing: all that I can say is that this honey looks much more like it has the stable isotope profile of corn syrup than it does of typical honey, this one jar.

And there are potential caveats.

There are some places where there are C4 grasses that grow naturally that maybe bees could be pulling pollen from, though in a lot of the studies I was reading, doesn't really show up that way in legit honey samples.

So this does fluoresce under the black light, unlike corn syrup.

It does have a slight honey smell to it.

So my educated guess would be that this is a little bit honey and a lot corn syrup, but it's hard to really prove that.

But once I had these stable isotope results, I did start to see some other weird things about this jar of honey.

One of them is that if you look at a jar of honey that's been sitting in your house for a while, you'll notice that these little bubbles form around the top.

Now, these bubbles seem to form in almost every other jar of honey that I bought and then opened and then allowed to sit, but not this one.

This one, just appearance-wise, looks different from the other honeys.

Natural honey contains an enzyme called glucose oxidase, which can break down glucose and, in the process, release things like hydrogen peroxide and oxygen, which can lead to these little bubbles up at the top.

But if there's not as much of that enzyme in this bottle, maybe that's why we're not getting bubbles.

And then I had someone set up a blind taste test for me where I tasted three regular honeys.

- That is 100% honey.

(bell chimes) That is a lot of honey.

I really only need a dab, but I think that is honey.

(bell chimes) That's 100% for sure, honey.

(bell chiming) These suspected adulterated honey?

Hmm.

Yeah, that tastes caramely more than honey-y.

I don't think that's honey.

(bell chimes) And for some reason, I decided to throw the corn syrup in there too.

Mm-mm.

That has to be the straight-up corn syrup.

(bell chimes) Holy moly.

Yeah, so I got them all right.

This one, it just doesn't taste...

It doesn't taste super like honey.

It tastes more like a light caramel syrup or something.

It's like a little bit of a honey note.

So I do think maybe they blended, like, 20% honey with 80% corn syrup or something.

But like, I did all this fancy chemistry, and I could have just tasted them.

Now, based on the stable isotope analysis, I had two suspects from the samples that George sent me, that I think he might have adulterated with corn syrup.

I don't know which ones he did, but A and B came back much more shifted to the left than the others, and I would not put it past him to have adulterated two (George chuckles) to see if I could find them.

We'll see if I'm right.

Okay, I'm literally watching the edit right now, and I was right!

I was right.

Science came through.

I was right.

George adulterated two.

This makes me so happy.

Oh, my gosh, this is great.

This is great.

Not only did I find a honey in the store that I think was fraud, but also George adulterated two, and he told me he was only adulterating one.

And I'm so excited that I figured it out with science.

Ah!