Scottish engineers develop artificial 'tongue' with a taste for spotting fake whisky

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You may have a taste for whisky. But no matter how discriminating your palate, an artificial tongue might be better.

Before you spit your single-malt onto your smoking jacket, read As It Happens guest host Piya Chattopadhyay's interview with the University of Glasgow's Alasdair Clark, one of the engineers who developed a device with an incredible ability to distinguish one whisky from another. 

Here is part of their conversation.

Mr. Clark, first of all, what does this "tongue" look like?

Well, it's not big and floppy and pink like our tongues. It is comprised of millions of tiny, little metal taste buds.

They are about a thousand times smaller than the width of the human hair and they're made of aluminum and gold.

When you shrink metals down to that size they take on these really weird optical properties. So when we shine light at them, they kind of shine a colour back at us.

So, what does it look like? It looks like a little patch of a little green square on a patch of glass.

And how does it work? 

So the optical response of these things, in other words, the colour that they shine back at us, is really affected by the local surroundings.

It gives you one signal when there's nothing on top of it. But when you put a complex chemical mixture on top of it, like a whisky, that colour that appears shifts ever so slightly.

We measure that tiny little colour shift to build up a statistical map of the chemical compounds in that liquid — something that's quite analogous to the human sensation of taste.

I'm not a super taster. I don't have precise taste, I suppose. How precise is this tongue device? 

Well, relatively precise. We tested it 300 times with 300 different samples and it was able to identify all but one of those.

But comparing precision between the artificial tongue and a human tongue can be a bit tricky.

And so when you've done these 300 samples, what kind of distinctions can it make between different whiskies?

It can make distinctions based on age. Say if you take the same whisky that's been aged for different length of time, it can tell you that.

It can also tell you if the whisky has been aged in a different type of cask — maybe a sherry cask, or bourbon cask, or a rum cask. 

So it is very good at picking up these tiny, minute chemical differences in the whiskies.

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Who would want to use this kind of device?

One is the huge market in counterfeit whisky. So the ability to be able to tell whether something is real whisky that's come from Scotland or Ireland.

But also maybe more mundane tasks like just monitoring the quality or the taste of beverages on a production line.

It doesn't necessarily have to be whisky. It could be any — soft drink, for instance.

So this artificial tongue isn't whisky specific — you can use it on other liquids?

Yes. Anything where you might want to make a measurement, an identification, of a complex chemical mixture.

So, other liquids, like beverages. You could train it to look for poisons. You could train it to look for contaminants in a water supply, for instance. 

So, of all the liquids in the world, why did you, who works at the University of Glasgow, decide whisky?

Yes... 

Maybe a rhetorical question?

Yeah. Yes, we saw the opportunity to buy a lot of whisky.

Because we're from Scotland, we're aware that counterfeit whisky is a thing. So when we're looking to test this tongue, we thought what better way to test it than with the different whiskies.

How sizeable is the fake whisky market?

As far as I'm aware, it's hundreds of millions of British pounds per year. So relatively large.

It's a mixture of high value ancient whiskies, which auction for tens of thousands of pounds per bottle and often turn out to be fake, unfortunately. 

And more mundane things like regular $20 bottles of whisky that are entering international markets, Asian markets in particular, that are being passed off as scotch whisky.

But, in fact, they're being manufactured elsewhere with a fake label slapped on them.

Now, there is some skepticism out there of your artificial tongue when it comes to whisky tasting. Charles MacLean, who is one of the top whisky tasters in the world, said this to CNN: "Flavour assessment in the whisky industry is done by smell, taste and texture. Of all the senses employed, smell is the most important. Whisky blenders and quality assessors rely entirely on smell. Our sense of taste is crude in comparison." To that, you say what?

I would say that we've chosen to call it a tongue, but what it's actually doing is making measurements of the chemical mixture of the liquid.

It's exactly the same way that your nose works. Your nose is taking in particulates of the liquid and making an assessment, or your brain's making an assessment, of the chemical composition of that.

That's the same sensation. So smell and taste are very related, particularly when you're trying to make artificial versions of them.

Also, I would say that this is not a replacement for people that are super tasters and that work in the whisky industry and the beverage industry.

This is just another tool that people can use in order to monitor the quality of liquids.

Written by Richard Raycraft and John McGill. Produced by Richard Raycraft. Q&A has been edited for length and clarity.