- Mexican Coke is a lie.

At least it is according to Johnny Harris who made a video a little while back, in which he found a study that claimed they tested Mexican coke and found zero grams of sucrose in it.

I tracked down that study 'cause I was curious and I confirmed that yes, the authors found zero grams of sucrose in a bottle of Mexican Coke.

Now cane sugar, which is what Mexican Coke claims to be sweetened with, it is the whole point of Mexican Coke, is just sucrose.

High fructose corn syrup, on the other hand is a mixture of fructose and glucose.

And the authors found both fructose and glucose in that bottle of Mexican Coke.

And the best part of this is I can actually test this myself using Benedict's test.

This is Benedict's solution.

It's a mixture of these three things and it reacts with carbon yield groups in reducing sugars like glucose and fructose to form copper oxide, which crashes out of solution as a red precipitate.

Sucrose doesn't have any carbon yield groups and it's not a reducing sugar.

So it does not react with Benedict's solution at all.

No copper oxide, no red precipitate.

Now as you'd expect, American Coke comes up positive on Benedict's test.

Ooh, I already see a color change because we know there's high fructose corn syrup in there, which means there's fructose and glucose.

See that reddish precipitate at the very bottom?

That is a positive Benedict's test.

You just never know if these things are gonna work or not.

That worked.

That was American Coke, which we know has high fructose corn syrup in it.

Fructose and glucose, both reducing sugars and both should show positive on a Benedict's test.

And do I have something on my teeth?

I did.

I had something in my teeth.

Where was I?

But there is only supposed to be sucrose, cane sugar in this bottle of Mexican Coke, not any high fructose corn syrup.

So we'd expect a negative Benedict's test where nothing happens.

The thing just stays blue.

Oh, it's already going.

I mean I barely just put it in the water.

Really?

And it's turning red within I'd say 30 seconds and then it just turns all the way red and we get a clear red precipitate.

Oh, there it is.

That is undeniable.

That is a red precipitate.

It's not looking good for Coke at this point.

Wow, this is where Johnny Harris stopped.

And no disrespect to you Johnny, but I am not Johnny Harris and he is not a chemist.

But I'm gonna dig a little deeper on the chemistry here.

So to do that, the first thing I'm gonna do is just confirm this result via another method.

I think what I'm gonna do is I'm gonna use a glucose, like a human blood glucose monitor.

And unlike Benedict's test, the glucose monitor doesn't just tell you whether glucose is present.

It actually tells you how much glucose is present.

So first I'm just gonna test this sucrose in water solution.

I put a lot of sucrose in this water.

I put exactly the same concentration of sucrose in this water as you would expect to see in a Mexican Coke.

As expected it says low meaning it is below the limit of detection.

And now I'm gonna test this solution of high fructose corn syrup, which contains 42% glucose, about 55% fructose.

Again, as expected the glucose monitor is working.

We are getting a reading here for glucose.

We expect that to be roughly 4.2 grams per liter.

And this is coming out at 3.8 grams per liter glucose.

This is actually not that far off.

So now let's test it on Mexican Coke.

There is supposed to be nothing but sucrose used to sweeten this bottle of Coke.

So we should get a reading of low.

And as you can see, we're actually getting literally the opposite like it's saying high, which means it's above the limit of detection for this glucose monitor.

So what I'm gonna do next is dilute the Coke one to 10 and try that.

And that is still high.

Alright, we're gonna just dilute it again.

We're gonna dilute this to one to 20 and we're gonna try it again.

And when I dilute it one to 20, I'm getting a reading here.

Alright, we got a number.

Okay, so 440 milligrams per deciliter.

By the way, look, this is funny.

If this were in your blood, that would be not good.

See the sad face, that means you need to go to the hospital.

And if we do a little math, 4.4 grams per liter, now we have to multiply that by 20 because we diluted one to 20.

So 4.4 times 20 is... (speaker fast forwardering) So 88 grams per liter of glucose in a bottle of Mexican Coke, you know, with very large error bars on that number is roughly what you would expect if this Coke was sweetened using high fructose corn syrup instead of actual cane sugar.

So now it is really not looking good for Coke.

I have to say, now I'm confused, like it's just really hard for me to believe that Coke would intentionally mislabel their products.

If you're Coke, you're trying to protect a brand identity.

Is this true of other sodas?

Like is Mexican Coke the only soda that you can buy in the US that's sweetened with cane sugar?

That would test positive on Benedict's test and that would show glucose readings on a glucose meter.

(upbeat music) As you can see here, I have been hoarding cane sugar drinks pretty much everywhere I went for the past month.

If I saw one, I bought it.

Anyway, I tested all of these and I found glucose in every single one.

So now I don't know if I can trust any of the labels that I see at all.

I need to take things one step further and make my own test cola.

This has only alcohol and flavorings and so I will take this and I will add either sucrose syrup or high fructose corn syrup.

And then I'll also add phosphoric acid, which is an ingredient in both Mexican Coke and American Coke.

Then I'll add carbonated water.

And first off, see if I can even taste the difference.

Wow, that tastes nothing like Coke.

Yeah, I cannot tell the difference.

Oh man.

Do not recommend trying to make your own soda at home.

This is not good.

Yeah, absolutely could not taste any difference here.

So let me just out of curiosity, let me run my glucose test on these.

Okay, not a surprise.

Also high.

What the- I was confused before, now I'm really confused.

Only table sugar went into this soda.

No high fructose corn syrup, which means no glucose, which means I should not be getting a high reading on this.

So I'm gonna go back to the paper that accused Coke of lying and I'm gonna just see what else I can dig up.

What is going on?

Alright, when I reread this paper, I clicked on cited by by which you should always do, and I found this paper where some scientists who work for the International Society of Beverage Technologists basically said the original authors don't know what they're talking about.

Now these two groups went back and forth for several years, eventually leading up to this diss track from the Beverage Technologist people.

Ventura et al reported discrepancies between types of sugars claimed on product labels and those detected in sucrose sweetened beverages.

However, their sucrose concern was almost certainly a failure to consider acid catalyzed sucrose inversion to free fructose and glucose, a well characterized phenomenon known to occur in the low pH environment of most carbonated beverages and a host of other acidic foods and beverages.

Thus, concern about types of sugars in HFCS and sucrose sweetened beverages appears to be based on incomplete understanding of sugar's chemistry and carbonated beverages.

Now this is about as brutal of a dunk as you will find in a scientific paper.

It's the academic equivalent of slapping someone in the face with your glove.

But it turns out that when you put sucrose in an acidic solution, that acid can split the sucrose apart, which forms fructose and glucose in a 50/50 ratio.

Now for comparison, when you use high fructose corn syrup to sweeten a drink, you get fructose and glucose in a 55/42 ratio.

So it is very, very close to 50/50.

And this breakdown the hydrolysis of sucrose into fructose and glucose, it is surprisingly fast.

At 70 degrees room temperature, it'll take roughly three weeks for half the sucrose to disappear, to the point where this bottle that I tested at the beginning of the video that has been sitting around for a month contained, from what I can tell, zero sucrose in it.

So Johnny Harris was right, but he was right by accident.

There probably isn't very much sucrose in Mexican Coke, but not because Coke or bottling plants are being shady.

Like even if you put sucrose in the bottle, you are very likely to end up with at least some fructose and glucose.

So can anyone really taste the difference between Mexican Coke and American Coke?

(drill whirring) (soft music) - Um, which would make it the Mexican Coke.

- I'm gonna go with this one as a Mexican Coke.

- We're going this, this is the Mexican.

- I think this one Mexican.

- And this is Mexican Coke.

- Mexican.

Now that would've been really embarrassing if I've been doing a video about this and I got it wrong.

Now, obviously I don't know the formulas for Mexican Coke or American Coke, but I do know that this Mexican coke has almost double the sodium as American Coke.

It's right here on the label, 45 milligrams of sodium in the American Coke, 85 milligrams in the Mexican Coke.

So clearly there is more going on here than just what it's sweetened with.

But what about everybody who claims they can specifically taste the difference between cane sugar and high fructose corn syrup in a soda?

Those people are just wrong.

Hey you, before you go, have you seen the latest on the PBS food channel?

They've got lots of delicious new videos, including new episodes of "Pan Pals".

It's a show that asks a simple question, what if two people from different cultures swapped dishes around a theme?

Just take my advice, don't watch this on an empty stomach.

There's a link in the description below.

Let them know we sent you.