Cognitive Daily

Any serious wine drinker will tell you she can distinguish between inexpensive, low-quality wine and the fancy premium-priced stuff. She may also claim the ability to discern the difference between wine made from different grapes, or produced in different regions of the world. Yet some studies have found that even so-called experts are unable to figure that “red wine” was actually a white wine dyed red, and nearly everyone seems to be swayed by the label on a wine bottle. Wouldn’t we all just be better off if we simply kept an old empty bottle of fine vintage wine and refilled it as necessary with the cheapest boxed wine we could find?

Not necessarily. Ordinary individuals can be trained to tell the difference between wines along a number of different dimensions. One key aspect of the flavor of a wine is “mouth feel,” which, as you might guess, describes the feeling of a wine inside of the mouth, before it is swallowed, and independent of smell. Can ordinary individuals be trained to discern wines solely based on mouth feel? Does everyone “feel” wine the same way?

Researchers have known for some time that not everyone has the same ability to detect tastes. Some people — “super-tasters” — are especially sensitive to a wide range of tastes. As it turns out, whether or not you’re a super-taster may come down to your ability to detect a single molecule: 6-n-propylthiouracil, or PROP for short. Those who can taste PROP find it incredibly bitter, but super-tasters are also extra sensitive to saltiness, sweetness, and even tactile sensations in the mouth.

Gary Pickering and Gordon Robert recruited 17 volunteers to sample a set of wines twice a week for 7 weeks (before you rush to sign up for their next study, be advised that all tasters had to spit out their drinks after sampling!). All the tasters were tested for PROP sensitivity, and 8 of them were found to be super-tasters. The study was conducted with nose plugs so that solely mouth-feel was rated.

Four different red wines were rated for mouth feel along dimensions generated by the tasters themselves. While they could use formal wine-tasting terminology, they were allowed to use any terms they wished to describe the mouth feel of the wines. Within a few weeks the tasters settled on 13 different sensations to describe the wines: Acidity, bitterness, saltiness, viscosity, heat/irritation, tingle, particulate (both in mouth and after spitting), smoothness (in mouth and after spitting), grippy/adhesive, mouth coat, and overall astringency. Reference scales from 0 to 150 were created for each sensation – for example, “particulate” could range from 0 (Johnson’s baby powder) to 150 (coarse sand). Most of the actual ratings chosen by tasters were between 0 and 10.

So after all this training, could tasters distinguish between the wines in a blind taste test? For the final tasting, they sampled the wines in a room lit with red light, so they weren’t even able to visually distinguish between the samples. Here’s the result for just one dimension of taste, smoothness after spitting:

Not only were most ratings for each wine significantly different from each other, but the super-tasters’ ratings were significantly different from the non-tasters for nearly every variety of wine. This difference between super-tasters’ and non-tasters ratings held for every dimension of mouth feel except for bitterness and viscosity.

Whether an individual is a PROP super-taster is determined by genetics, and clearly super-taster status has an important impact on taste for wine. But whether or not an individual is a super-taster, it’s clear that with some training, many individuals can readily discern many differences between varieties of wine. It would be interesting to see how the results of a study like this might change if the wines were labeled (and perhaps sometimes mislabeled) during testing.

Pickering, G.J., Robert, G. (2006). Perception of mouthfeel sensations elicited by red wine are associated with sensitivity to 6-n-propylthiouracil. Journal of Sensory Studies, 21(3), 249-265. DOI: 10.1111/j.1745-459X.2006.00065.x

Comments

#1 Abel Pharmboy
March 5, 2008

Absolutely fascinating – I’ll have to remember to link to you for The Friday Fermentable.
I wonder if the genetics of PROP sensitivity account for why some people are accepting of almost any average wine while other have to seek out wines of higher quality because of real differences in perception.
#2 Simon
March 5, 2008

This story from Slate describes a professional wine critic who, after testing, proved to be a nontaster. He was, however, vaguely sensitive to PROP, and extremely sensitive to Kool Aid.
#3 bg
March 5, 2008

Ugh, is that why expensive wine tastes like rubber to me? PROP: Horrible, burned rubber. Yuck.
#4 Cris
March 5, 2008

Very interesting! This makes all sense. It also raises another interesting questions: do the super tasters smoke or are used to spicy food or any type of diet that may alter the food/drink taste? I drunk good wine for some time and at the end I could “feel” when I was not drinking good wine, but I stop drinking for health reasons and today I cannot tell the difference anymore as I could not before affording such habits.
#5 Tom Levenson
March 5, 2008

Great stuff. I filmed Linda Bartushok, the discoverer of the supertaster/PROP sensitivity discover a long time ago (especially in dog years). I was struck by the simplicity of the concept, and the ease of the test to identify the trait.

There were many interesting things in that shoot for me; perhaps the most was the one hinted at by BG above: that being a supertaster is not so super — very high sensitivity to the canonical four tastes does not make for happy eating always, especially in childhood. Sweet tastes way too sweet and so on.

(Linda did not administer the PROP test to me, but she did stain and observe the density of tastebuds on my tongue; apparently, I’m a borderline supertaster, most likely. And anecdotally the downside potential turned out to be true in my case — I was very sensitive to particular tastes as a child and a very picky eater. I’m still sensitive (such a delicate plant…) but no longer, alas, nearly picky enough for the realities of a middle aged metabolism.)

Re wine — what a sweet experiment. There is a fair amount of evidence that it is possible for trained tasters to distinguish a great deal in wine, but what’s nice about this is the elimination of the complexity of flavor (olfaction) to demonstrate that there are significant, detectable differences between the varieties of wine.

One human subjects question though: what are the ethics of training someone into a more expensive bracket of the wine world. No more 2 buck chuck for this crowd.
#6 Tony Jeremiah
March 6, 2008

It would be interesting to see how the results of a study like this might change if the wines were labeled (and perhaps sometimes mislabeled) during testing.

That would be interesting. Especially in light of a recent study I heard reported in the news concerning a rather interesting take on the placebo effect.

Apparently, persons paying discount prices for prescription drugs, tend not to have as high a recovery rate from whatever ailment the drug is supposed to fix, relative to those paying a higher price for the same drug. The explanation put forward is that persons paying a particular price assume that ‘you get what you pay for’ (e.g.,a cheap price implies an inferior product).

So I also wonder what would happen to the ratings if a cheap wine label is placed on a bottle that actually contains an expensive wine, or, an expensive wine label is placed on a bottle that actually contains a cheap wine.
#7 JC
March 6, 2008

Yet some studies have found that even so-called experts are unable to figure that “red wine” was actually a white wine dyed red…

The fact that color can change taste should not be seen as a criticism regarding the abilities of “so-called experts”. On the contrary taste is a multisensory experience involving smell, touch, “mouth feel”, and yes even vision.
#8 Bioorganic chemist
March 6, 2008

A recent paper on wine labeling and perception (as measured by functional MRI):

Marketing actions can modulate neural representations of experienced pleasantness (Plassmann et al., PNAS 2008 1050-1054)

The short version: the brain has a stronger reaction to wine with a more expensive label than to wine with a less expensive label: expensive wine (or, rather, wine thought to be expensive) tastes better!
#9 frank habets
March 9, 2008

As a super-duper taster, I gotta vent here.

I’ve always detested the label ‘finicky eater’. There are a lot of foods that I found absolutely vile, including many vegetables. And grapefruit juice is like battery acid.

And no, I’m not a ‘princess and the pea’ type. So here’s a word to advice to adults who force kids to eat their veggies: if the kid is a super-taster, this amounts to child abuse. I’m not being facetious; it really is the equivalent (taste-wise) of shoving feces down a kid’s throat.

BTW, I think there are degrees or variants to super-tasteness. PROP might just be the tip of the iceberg.
#10 wine
March 11, 2008

Wow! really very interesting that being a supertaster is not so super — very high sensitivity to the canonical for tastes does not make for happy eating always.which should provided Within a few weeks the tasters settled on 13 different sensations to describe the wine.
#11 Annie
March 11, 2008

How do you find out if you are a super-taster? Somehow I doubt PROP is available at my local grocery store.
#12 Dave Munger
March 11, 2008

This BBC test seems pretty good:

http://www.bbc.co.uk/science/humanbody/body/interactives/supertaster/
#13 Patchouli
March 27, 2008

Good news for white wine lovers
“Says Michael Aviram, D.Sc., lead investigator in the study and a professor at the Technion-Israel Institute of Technology in Haifa, Israel. Besides providing a more healthful alternative to those who prefer the taste of white wine over red, the development is also promising for those who cannot drink red wine, including some migraine sufferers whose condition can be exacerbated by red. “