I used to work in a brewery, and part of my job was beer tasting. We used the same nomenclature and tasting training as the wine industry. It's a qualitative assessment, but there is a lot of science behind it, and the training is actually quite difficult. You actually train on specific samples with a single taste, initially very unsubtle and clearly labelled. Then to pass certification you have to do it completely blind. Next level up you progress to subtler tastes and repeat. The really advanced people are genuinely capable of discerning very specific chemical compounds with a very high degree of accuracy.
The point I want to make here is that this is an actual discipline in its own right, and the people practicing it in industry aren't quacks. They have to pass examinations which test their skills empirically and objectively against blinded reference samples. You can't get certified without it, and no one can pass without spending some serious effort getting the training. I didn't stay in the industry long enough to become an expert, but I have done the basics.
We used to do assessment sessions where you would rank 40 unlabelled samples lined up on a bench. Each one would be scored between 1 and 10 on a defined scale for several criteria. Both experts and novices like myself would do it, and then they would do stats on the results of 20 or so people to see how everyone in the expert group compared, and how the novices did compared to the collective expert assessment. So in industry, it is used in a semi-quantitative way. (We have stuff like GC and GC-MS for more exact quantitative measurements.)
> f they are tasting it blind ... their taste is accurate
It would be more accurate to say the tasting would be less subjective. I don’t think “accurate” is a good word - people all taste things differently due to different taste buds and psychological wirings.
But even then, removing the label doesn’t mean people taste anything objectively. They are bringing in their own biases - maybe they are tired, hungry, or stressed.
Finally, (and this is my primary point), to taste is not just to detect the presence of certain molecules. That may be (part of) the objective experience, but is only part of the puzzle. To taste something is to subjectively interpret my enjoyment and experience of something edible. Adding the label and cost can be part of that experience.
Further, the effect of showing the label has a pretty consistent directional impact on ratings. What makes that any different than, say, blocking a specific taste bud receptor and changing what molecules are perceived? I suggest the only difference is the abstraction layer at which the influence occurs.
Taste is inherently subjective. Removing a label does not make it more accurate. I argue further that labels/prices add no more subjectivity than a persons particular configuration of taste buds and neural wiring.
The latter is not subjective. The experience might be, the qualia might be, and it will change with training and priming, but the raw detection is what the parent is talking about and that is objective.
The training part is very much about learning to identify specific chemicals, or groups of chemicals. That absolutely is raw detection, as you say. Let me provide some examples. For the "level 1" training, the most basic stuff, samples would be things like: plain water, acid (very dilute sulphuric acid), alkali (very dilute sodium hydroxide), metal (copper and nickel metal coins in a bottle of water), rubber (rubber tubing cut up in a bottle of water), salt, sugar and a few others I've forgotten (this was 22 years ago), maybe some other major categories like aldehydes. Just for the record, you don't actually drink any of that stuff down, it's tasting only and its very dilute! When the solutions are all clear, being able to identify each blind from some anonymised samples is surprisingly difficult, especially when diluted so it's more subtle. But it's absolutely possible with practice.
The higher levels are all more subtle things like many different flavour compounds. For wine and beer, almost exclusively aromatic hydrocarbons, along with esters and other flavour compounds. I never did this but it's the same process, but it's much more difficult. Instead of under 10, you have an industry-standard reference set of IIRC around 60 compounds, and you have to be able to identify each and every one blind when diluted in isolation. And obviously in a drink you have to be able to identify them all individually in combination as well. This is the part that takes the most time and effort to master. And it's these people that I wouldn't question too much regarding their skills, because they actually had to pass objective assessments to demonstrate those skills. This is really hard!
This is why I'm a little disappointed that the original article mentioned using students. They would be unlikely to have achieved that level of competence. It takes many months, if not years, of regular practice to get to that level. I spent a year doing the basic training and then continual daily testing and monthly assessments, and while I still class myself as being at a very basic level, I'd still likely have more practical experience than them.
Regarding subjectivity and the "experience" of taste, that's absolutely taken on board as well. But it's a separate question. For where I worked, every product had a spec sheet, mostly physical and chemical properties but also a taste profile. The professional tasters could make sure it met that profile exactly. The rest of us just made sure it looked and tasted as a consumer would expect it to.
For those who are wondering about why those specific "level 1" tastes, they aren't random and they are actually serving an additional purpose. Those are to also pick up on product contamination. Metal and rubber from storage tanks and pipework. Acid and alkali from cleaning agents and coolant. I actually had to check for the latter once when we had a potential set of hairline cracks in a tank suspected of leaching coolant [in beverage production, they use very concentrated KCl since it's non-toxic if it leaks, but at pH14 it's nasty stuff].
If we're talking about an objective assessment of the molecules in the bottle, then I agree there is an absolute and correct answer. But in order to taste something, there has to be a taster, and that will vary between individuals.
Very true, however there's a great deal of pretentious BS in the wine-tasting game. No matter how long one has been tasting wine, ultimately one has to have some degree of competence to analyze and then describe what one is actually tasting.
That said, I'm sure people can be trained to develop wine-tasting skills and that they actually get better with experience—but ultimately one cannot make a silk purse out of a sow's ear no matter how good the training.
I claim no great expertise in the wine-tasting/oenology game and I'm sure that I'd likely have been fooled by the dyed 'red' wine as described in the article (if I were to be so fooled then I would have had a certain class of red wines in mind when doing the comparison).
Nevertheless, I do have little wine experience and I have found that it is often just sufficient to catch out the true BS artists. One only has to be marginally better at discriminating which wine is better than they are then their BS status becomes pretty obvious.
I recall a couple of decades ago attending a rather expensive black-tie blind tasting of about 25 so-called experts with an engineering colleague of mine (he too had had some experience in tasting reasonable-to-good wines). As techies, we were the odd ones out, as we didn't work in the wine industry and most of the others did. Moreover, the master of ceremonies was a long-time well-known wine writer for a large newspaper and had a number of wine books to his name.
As I mentioned, it was a blind tasting and the wines were the then newest (just released) first and second class Bordeaux growths with the exception of the Mouton Rothschild (it was either unavailable or too expensive to include). This much we all knew before the tasting. The aim of the exercise was to determine the best wines then rank them in order using the 3-7-10 scoring system.
Anyway, like many blind tasting, it turned out to be pretty much of a shambles. The so-called experts including the wine writer were all over the place, mistaking first growths for second and vice versa. A final exercise for everyone was to guess the Lafite Rothschild, for without the presence of the Mouton, it was the most expensive wine there. (BTW, it's not the first time I've seen our wine writer in action and he was again true to form on this night.)
The only ones to get the Lafite correct were my colleague and I (I nearly made myself sick from trying to hide my smirks it was so damn funny)! Incidentally, the Lafite wasn't all that hard to guess, as it was true to form and it was also the best wine of the night.
Now back down to earth. Every winter I used to attend a different group for food and wine dinners. They too were black-tie events and were held approximately a month apart. It was organized by a guy who owned a wine cellar/emporium and the dinners/tastings were held at the cellar. This guy was truly one of the best and up there with the likes of Hugh Johnson and Michael Broadbent—he was certainly the best I've ever come across. Most of us were awestruck by his ability.
Incidentally, all four of these guys are in the Wiki List of wine personalities: https://en.wikipedia.org/wiki/List_of_wine_personalities. Thus is goes to show that sometimes BS can get one almost everywhere.
Incidentally, with respect to being fooled by the dyed white wine. It seems to me that if these oenology student were actually fooled then they must have been familiar with lighter style reds à la Provence or similar and comparing the wine with those reds. For I fail to see how any robust red—Bordeaux first growths, Californian (Stags' Leap Cabernet, etc.) or Australian Reds (Grange or similar) could ever be mistaken for a white or vice versa, irrespective of color or in a blind tasting, for these big red styles are just too distinctive to be mistaken for whites in any circumstances. Even neophytes should be able to tell the difference.
Absolutely agreed 100%. I've been to a few organised tasting events, and I think at that level it's pretty much all pretension and style over substance. It's for the experience and the entertainment, and at that level I have no problem with it.
I just wanted to provide a perspective about how it's used industrially for wholly serious purposes, where people train to objective standards, and have to pass formal examinations to demonstrate their skill. You can't pass them with pretension, they are the real deal. The simple examination was tough enough for me, and that only increased my respect for the really skilled people.
At the industrial level, the tasting is also done alongside and correlated with quantitative scientific analysis. The lab I worked in ran each batch through GC-FID (basic stuff), headspace-sampling GC-FID (volatile aromatics), alongside a battery of additional physical and chemical analyses (too many to list here, there are at least 20, the big brewers take product quality and safety really seriously). And we had GCMS and LCMS systems and other more detailed tests as options on demand to test more obscure stuff like metal content (for making Marmite yeast extract where iron levels are important, apparently).
One of the key roles of the tasters isn't just at production, it's to assess how the character changes over time when assessing shelf-life, where there may be negative things like oxidation, bacterial contamination, lightstruck reactions, and other factors which influence the taste change over time. All very rare. Saw one example of oxidation in my entire time there, in a small batch for export. We would taste every batch once a month over the course of its entire shelf life. Bottles, cans, kegs, everything. That's where we would do group assessments where the qualified tasters and ourselves would taste everything blind.
However one comment before I go, what you're describing seems not that dissimilar to the perfumery business. Training for that is intense and takes years.
It's a rare experience for me to come across someone who's done the kind of work you have. On the few occasions I have and I follow up with questions, the person usually clams up because of trade secrets or such—you know 'our chocolate is smoother because of our secret process' etc., etc., so I've never gotten to the bottom of the aspects of the subject that I've been most curious about.
I'm not a chemist but given the number of courses I've done where chemistry was one of compulsory subjects, I reckon I ought to be. ;-) Once, I added the years up that I'd studied the subject and it came to over a decade (that, of course, includes high school). If it hadn't been for considerable duplication of subject material due to the silly way courses were constructed then, by now, I ought to be expert in the subject. But alas that's not so.
Now back to your comments:
"If they are tasting it blind (with no preconception), their taste is accurate."
"We used the same nomenclature and tasting training as the wine industry. It's a qualitative assessment, but there is a lot of science behind it, and the training is actually quite difficult. You actually train on specific samples with a single taste, initially very unsubtle and clearly labelled. Then to pass certification you have to do it completely blind.
Next level up you progress to subtler tastes and repeat. The really advanced people are genuinely capable of discerning very specific chemical compounds with a very high degree of accuracy.
Now let me also include my facetious and somewhat unfair comment (unfair for reasons I develop below):
"… I'm sure people can be trained to develop wine-tasting skills and that they actually get better with experience—but ultimately one cannot make a silk purse out of a sow's ear no matter how good the training."
Further down, you'll become aware that the 'silk purse/sow's ear' comment becomes very relevant.
Before I proceed I must add that decades ago one of the 'sins' of my youth was to spend a little time working in a vineyard/winery—not as a winemaker or specialist but as a general dogsbody. Nevertheless, when knowledgeable people who regularly win awards for their wines surround one, one cannot but help pick up a few valuable tips.
OK, back to the comments. All these quotes have common threads, which are, (a) about how do you calibrate the taste and olfactory processes of different individuals so their 'output' is uniform and thus useful to others, and, (b) when exposed to the same stimulus how do different individuals differ in their experience of it. We're confronted with the ancient conundrum that's as old as philosophy itself—not to mention the subject of countless philosophical dissertations—some of which I once had to study. It boils down to this: I cannot experience a given physical phenomena and accurately remember it then jump into your head to see if you/your senses experience it the same identical way that I did when I was in my own body.
Of course, there are two issues here. The first is that one's physical sensors (of taste, smell etc.) have given (nominal) sensitivities and that these differ between individuals. Moreover, they change dynamically over time and with the type and strength of the input signals (tastes). These sensors also possess bandwidth and detection thresholds in the physical sense. One experiences (directly perceives) sensory data from these senses (as say in a blind tasting, or feeling something) but that's about as good as it gets because one can have errors directly associated with perception. For instance, at one end of the spectrum you've lost your glasses and you mistake a ballpoint for a pencil, at the other extreme we've the case of the man with visual agnosia that Oliver Sacks outlined in is book The Man Who Mistook His Wife for a Hat. Then there are interpretation errors (errors of thought/mental processes), which can be caused by any number of reasons from having a vivid imagination, to schizophrenia, to reacting badly to a normal everyday stimulus because of an ongoing memory of a similar bad experience that one has had in the past.
This can quickly become a real can of worms, as things can get so inextricably intertwined and complicated. Where do plain old errors of perception end and interpretation errors actually begin? Let's take an extreme case, say someone is on LSD and they see or feel ants crawling up their arms or spot flying pigs then we have to ask what is at fault? Has the physical sensory system been corrupted and the data it's issuing is garbage, or is it that the sensory data is OK and that mental interpretation turns out junk (like a RAM fault), or is it a combination of both? The modern work/interpretation of this stuff essentially began with the sense-data constructs/notions of B. Russell and G.E. Moore et al, ca 1900, now much of it rests in the hands of neurologists.
Likely, these matters all sound rather hypothetical; the trouble is that the combined 'product' or output of these processes has real consequences in that they distort our perceptions of reality. In practice, they regularly play a large role in our day-to-day experiences. Essentially, they collectively add unwanted distortion to the output (that's to say our composite perception of an event is often in error).
For example, as a young kid I once grossly over-indulged in chocolate and made myself physically sick, afterwards I never ate another skerrick of it for over 20 years (as it made me feel sick whenever I tried ) [In hindsight, it was likely a damn good outcome.] Thus, emotion, likes, dislikes and experiences all play a huge role in interpretation.
The dynamics of all of this are seemingly overwhelming—perhaps confusing is a better word. So for the moment, let's reduce this to the simplest scenario (as per your "If they are tasting it blind (with no preconception), their taste is accurate." case. If I eat a sweet chocolate then immediately taste wine, it will taste bitter (even so a sweet sauterne); if I've just eaten a complex curry then my taste threshold changes (usually by desensitising/increasing the perceptible detection threshold), moreover, it will do so in a non-linear way (that's my experience anyway).
For example, take the case where I've not eaten (i.e.: my palate is 'clean') and (a) I dilute a sugar-water solution to the threshold to where I can just detect the sweetness, and (b) I dilute a water-denatonium (Bitrex) mixture to the point where I can just detect its foul bitterness. Then eating just about anything will alter those thresholds (usually by desensitising them but not always)—and the extent of this desensitisation will have occurred in a non-linear way. That's to say the thresholds will not desensitise to the same extent for each type of taste. If I then add a taste bias, add sweetness, bitterness, etc. into what I eat next, then the detection threshold for each chemical will change yet again. Moreover, it will again do so in a non-linear manner (this further compounds the effect).
Similarly, my taste bandwidth is reduced (here, I use the term 'bandwidth' to mean the extent to which I can differentiate varying degrees of sweetness/bitterness—essentially the range of different chemicals that I can detect for given concentrations of each). [Excuse my limited nomenclature here, my profession is IT and electronics, so it's those terms that make sense to me.]
Essentially, all of our senses have inbuilt Automatic Gain Controls, Automatic Bandwidths and Automatic Thresholds. And all of our various senses dynamically adjust or 'recalibrate' their thresholds to different detection levels depending on (a) the amount or level of the input stimulus/stimuli and (b) the intrinsic characteristics of those stimuli (type of chemical, etc.).
(Here, I've used both singular and plural deliberately, a singular stimulus will solicit a specific response, multiple stimuli will interfere with one another and thus give another different and separate response (as with intermodulation distortion in electronics, the resulting products (new tastes) of the combined responses will then be different to their singular counterparts. Furthermore, it's unlikely that the taster will be able to separate out the new taste(s) into their previous constituents—that is unless he/she does so from experience and or memory.)
Moreover, the sensitivities of our various senses and their recovery times (i.e.: the default input state after a given period of rest after in which no further stabilisation occurs) vary both over the short term (minutes/hours/days) and long-term (years/decades). We know this as we've many well documented cases. For example, there are thousands of instances where soldiers have been wounded on battlefields and their otherwise extremely severe pain is suppressed to tolerable levels—often for days afterwards. My understanding is that battle is such a terrible, emotional and cathartic experience that their perceptions of pain recalibrate as a coping mechanism. Years or even decades later when the same soldiers experience even a much lesser pain for whatever reason in normal civilian circumstances then they do so to the same extent as everyone else. Essentially, they now experience a considerably great pain for a lesser stimulatory input than they did for their battlefield injuries (sometimes this perplexes them greatly, as they worryingly perceive that they've now lost the courage and stamina that they once had.)
The drums still had their CAS numbers, IUPAC info/chemical formula and InChI identifiers so I knew exactly what I had. I ended up with a wide collection of about a dozen different chemicals whose structures ranged across the three most common musk types: nitro/xylene/ketone-like, macrocyclic ketones and polycyclic/galaxolide-like musks.
You can imagine what the old factory smelled like while I emptied out the drums, it stank to high heaven and you could still smell the musks way down the street (not surprising really, given that the human olfactory detection threshold for some of them is supposedly in the ng/l range). (Incidentally, whilst I can't immediately recall the exact details, the older-type nitro variety are potentially explosive, these ones were modern variants (isomers, enantiomers or whatever—I can't remember), thus that wasn't an issue—noticeably, the drums didn't have any hazard warnings to that effect.)
When I commented to my colleague to the effect that I hope we don't get complaints about the stink from those in nearby buildings he retorted "what stink?", he then stuck his nose in the open bung hole of one of the drums and said "it only smells a bit oily to me". This immediately rang alarm bells, as I was aware that he had no difficulty smelling other things.
This led me on a quest to understand more about synthetic musk chemistry and to find out why a comparatively large percentage of the population cannot smell the stuff because of minor genetic differences in their makeup (methinks that must be a problem for the marketing departments of soap powders)! A month or so later I put a small selection of the chemicals into the smallest type of Tabasco sauce bottles, 60 ml, (as a chilli eater I've lots of empties) and took them along to one of the regular social nights I attend. The group is about 20 in size and we do nothing other than wine, dine and yak BS well into the evening. Furthermore, many are rather opinionated about wine and continually argue over which wine is best on the night (of which there may be up to six or more bottles thereof). That said, I've never seen a bottle there that cost more than a low two-figure sum let alone a Bordeaux first growth! Unsurprisingly, knowing my friends, there are two chemists in the group.
Testing the musks out on this 20-something sample, I found that roughly 30% could not detect the musk odour and it included one of the chemists (somewhat to his chagrin), whilst a reasonable percentage of those who could detect it complained that the smell was so overpowering that it would put them off their food. Now that's a contrast!
This brings me back to the human calibration matter and your comment "The simple examination was tough enough for me, and that only increased my respect for the really skilled people." Absolutely, as per the highly respected cellar owner in my previous comment. So where does this leave us? Clearly human perception of odours is highly variable. This quote from an article† that I read when researching the musks sums it up reasonably well:
" Human perception of the odour environment is highly variable. People vary both in their general olfactory acuity as well as in if and how they perceive specific odours. In recent years, it has been shown that genetic differences contribute to variability in both general olfactory acuity and the perception of specific odours. Odour perception also depends on other factors such as age and gender."
This brings me back to your other points:
"At the industrial level, the tasting is also done alongside and correlated with quantitative scientific analysis."
Right, that correlation is something I want to learn more about but I'm not expecting you explain it. Knowledge of it is important to sort the crap and BS out of 'unscientific' wine tasting—and for that matter—many other tasting experiences, disagreements, arguments, etc., such as why some like truffles and others do not, or why as a kid I'd eat all green vegetables including spinach, broccoli and cabbage whilst there'd be a screaming match from a sibling when given them. Similarly, at the age of six why I stopped my mother diluting my tea with hot water after she poured it. Then, within a week of that, I demanded that she stop ruining my tea by adding milk and sugar to it—right, I've drunk it black ever since.
Coming back to the musk matter, I've had many a discussion over characteristics of various wines with my chemist friend (the one who cannot detect the musk odour) and we rarely agree, each coming to a different conclusion over one characteristic or another is best. This led me to the inevitable conclusion that his failure to detect the musk may make him more capable of detecting other types of odours than me and vice versa. I've never read any surveys or statistical correlations of the population such as those who can and can't detect musk versus their perceptions of various different wine characteristics (but then I've never done a proper search of the literature either).
Thus, I'd imagine what you say below perhaps ought to be able to enlighten us (if specifically applied to the matter):
"The lab I worked in ran each batch through GC-FID (basic stuff), headspace-sampling GC-FID (volatile aromatics), alongside a battery of additional physical and chemical analyses (too many to list here, there are at least 20, the big brewers take product quality and safety really seriously)."
…And so should this:
"And we had GCMS and LCMS systems and other more detailed tests as options on demand to test more obscure stuff like metal content (for making Marmite yeast extract where iron levels are important, apparently)." Altogether, I reckon your approach was pretty comprehensive, there's not much left to chance. It's belts and braces level stuff.
Over to you! Have I been living under a mushroom or just ill-informed, or could there actually be a complex relationship between one's ability or inability to be able to detect musk and the ability to detect or not detect other volatile aromatics that, say, are in wine and other substances? Essentially, do you know anything about this, if so is there a well-understood position or are we into new territory?
Given my experience and 'straw poll'/small sample, from my perspective there's a tiny modicum evidence that seems to suggest it. Moreover, given the enormous complexity of the matter and the complex non-linear interrelationships between all the various 'components' I'd not be surprised if there were. (As from my previous experience with other complex systems, almost inevitably new tertiary effects arise. The trouble is that one never knows when or where they'll turn up and what form they'll take—that is until they do.)
Other matters will have to wait for now.
† https://bmcneurosci.biomedcentral.com/articles/10.1186/1471-...
I later did a PhD in areas including developmental biology and immunology, and went to some talks by researchers on fly olfactory receptors and memory, which I'll come back to. I didn't do research in this area myself (I was looking at vascular development); it was seminars from visiting researchers. So bear in mind this is secondhand!
I think your comments about sensory experience, differences between people with different genetic backgrounds and so on are pretty much how I understand things myself.
Smell is one of the most, if not the most, primitive senses in the body. While we can philosophise about whether individuals experience the world in the same way, and proving it one way or another is very difficult, if not impossible, a great deal of this basic sense is essentially "hardwired". One of the best talks I went to was from a researcher using genetically modified insects with fluorescently-labelled neurons, which lit up when activated but were also visible when inactive as well (IIRC they used two colours). What was really interesting here was that under the microscope, they could visualise, in real-time, the olfactory receptors, the neural structure linking it to the brain, primarily the area associated with memory. What really struck me was that this was effectively (in computer terms) like the address lines on a memory bus. Each different olfactory receptor appeared to activate a different combination of neurons. Kind of like high and low voltages on lines on a parallel bus. That directly activated a response, be it innate or learned. That could be a danger signal, triggering an immediate physical response e.g. "jump", or positive e.g. "food". I did ask the question about the parallel with computer systems, because it just looked so obvious, but they (rightly) said that it certainly looked that way, but it would take a lot more work to prove. And in biological systems, information transmission is often based on frequency encoding rather than simple on or off, so who knows, but I found this absolutely fascinating. And it makes one wonder whether the "address lines" are wired up randomly and you learn from experience, or if they are actually effectively hardcoded, or a combination of the two. I wouldn't be surprised if it was the latter.
So I think that if we can draw a parallel from insect to human senses (and I think, at the physical level things will likely be very conserved for such a primitive sense), we have a large repertoire of receptors, connected directly to the brain, likely memory to elicit an immediate learned response. I suspect our experiences will be largely the same bar genetic differences around selected receptors, kind of like red-green colourblindness. We will have a combination of innate and learned responses to given stimuli. We all have an immediate and negative reaction to certain "danger" signals. While having a varied response to others; I imagine there's both a genetic and learned components here.
You're absolutely right about "gain". When doing the tasting we would have a stack of dry "table water" biscuits to "reset" the palate. You can really tell the difference, though it's subtle.
In terms of different perceptions between individuals, that's the main reason for training with a "reference set" of chemical compounds. It makes it objective instead of subjective. You learn to detect each one in complete isolation, and if you're completely physically incapable of detecting it, you should be able to pick up on that. Maybe like red-green colourblindness you can compensate for it if other similar receptors are slightly stimulated? I don't know. Either way, that standardised reference set should mean that everyone is trained to the same standard and knows that "this taste is this named flavour", even if their "experience" of that taste is different (we can never know).
Kind regards, Roger
"They may well be using LC-MS-MS time of flight on every sample now, for all I know, to identify and quantify every single organic molecule."
There seems no reason to believe this isn't possible. After all, insects (bees being the specific instance I'm aware of) can detect pheromones to phenomenally infinitesimal amounts, so it all hinges on the sensitivity of the receptors/sensors.
I recall hearing a talk on a radio science program several decades ago by a guy who invented one of the sensors for GC-MS. Can't remember all the specifics but I do recall his illustration, it seemed rather impressive to me at the time. That was if you gave him a thimble full of a chemical that wasn't in seawater and he placed the thimble in a body of water such as a large harbour, then he'd be able to detect traces of it a week later. He also referred to the year this resolution was possible which was 1957 (perhaps that was the patent date). Whether he was exaggerating or not I don't know.
If that was the state of the art 64 years ago then I'd not be surprised of the sensitivities you suggest. I'm also reminded that a few years back, I came across a book in a second-hand bookshop titled Pesticide Identification at the Residue Level American Chemical Society, Advances in Chemistry series 104 (1971). In Chapter 1 titled Possible Limits of Ultramicro Analysis, page 3 has a fascinating and very informative diagram (figure 1) titled Map of tracer cosmos. [Apologies if I'm stating the commonplace here, this isn't my day job.] It's a triangle-shaped diagram together with LHS and RHS axes. The LHS axis is labelled is Levels of Molecules and graduated from 10^0 at base of triangle to 10^21 at its apex, the RHS one is labelled Levels of Concentration and it is graduated from 10^-21 at the triangle base to 10^-3 (near but not at the apex). The x axis along the base of the triangle is labelled Maximum Number of Compounds at Each Level of Concentration, and it's graduated at 10^0 at the base's centre point (.i.e.: perpendicular from the apex) and the gradations extend to 10^10 on either side of that point (at the edges of the base of the triangle).
This is a wonderful diagram, I can't ever recall coming across it in all those years I studied chemistry. What's immediately obvious are myriads upon myriads of different chemicals one's likely to find at extremely low concentrations. This book also has an excellent section on GC-MS, detection of residues and related topics. The point of troubling you with all that is that the detection sensitivities shown in the book are now 50 years old and they seems remarkably good. For example, organophosphorus and organochlorine pesticides could easily be detected down to 0.05 microgram back then—mind you, that's still one hell of a lot of molecules whatever that number is (the compounds are given but I'm too lazy to apply Avogadro to find out).
I've often thought I like to own a GC-MS or LC-MS, I'd have a ball, at least until the novelty wore off. ;-)
"By the way, little if any of this is a "trade secret". The analyses are largely standardised across the industry (and validated using reference laboratories)…"
Yeah, makes sense these days with those analytical tools. That discussion is like the Coca Cola formula argument, Pepsi worked that out years ago, nevertheless they still want to differentiate.
"Smell is one of the most, if not the most, primitive senses in the body. <…>While we can philosophise about whether individuals experience the world in the same way, <…> and proving it one way or another is very difficult, if not impossible, a great deal of this basic sense is essentially "hardwired".
Right, qualia and the mind-body problem at their basics is 101 philosophy and they go back to Aristotle et al; at the discussion's 'high' end, the heavyweights are still slogging it out (and it's well over my head). In essence, comparing the differences in one's own 'sense data' [as per Russell, G.E. Moore terminology] and or against the sense data of others is nonsensical and must be equated out of any measurement discussion (there being no external reference to clamp to). As discussed, that's where training and repeated testing becomes essential if objective measurements/comparisons are needed.
"<…>a researcher using genetically modified insects with fluorescently-labelled neurons, which lit up when activated but were also visible when inactive as well (IIRC they used two colours). <…> they could visualise, in real-time, the olfactory receptors, the neural structure linking it to the brain, primarily the area associated with memory interesting here was that under the microscope."
You're right, that is fascinating stuff. One may not be able to measure a person's qualitative (perceptual) response but I can envisage a system that would allow one to quantitatively measure say the response to those synthetic musks to which I was referring earlier. Detecting that info would be useful for any number of reasons (as with Ishihara colour vision tests, it could be used for, say, a preliminary test for those who want to be perfumers).
"Each different olfactory receptor appeared to activate a different combination of neurons."
Apropos my comment immediately above, that presupposes that any analyser can distinguish between a learned response and an innate one. For instance, my example of turning myself off chocolate as a kid. If one couldn't differentiate that learned signal from my innate sense of chocolate smell then it would be pretty useless. Then, that perceptual analysis would no doubt be processed elsewhere in the brain (I think I've answered my own question here).
"And in biological systems, information transmission is often based on frequency encoding rather than simple on or off<…> I wouldn't be surprised if it was the latter."
I'm not familiar enough with biological systems to make sensible comment about that except to say that if we definitely know there's a solid basis for the 'frequency encoding' argument, then could both be relevant if synapses process variable amounts of neurotransmitters (as they do)?
"I suspect our experiences will be largely the same bar genetic differences around selected receptors, kind of like red-green colourblindness. We will have a combination of innate and learned responses to given stimuli." <…> "Maybe like red-green colourblindness you can compensate for it if other similar receptors are slightly stimulated? I don't know."
I've spent much time in electronic vision systems, television, image sensors, etc. and I can say that none of them can match the human eye in sensitivity and dynamic range let alone say a cat's eye, which is about five times as sensitive (it can detect a single photon). Modern electronic sensors are remarkably sensitive and we can get them to do great things in our smartphones. The trouble is that it takes a great deal of electronics to get them to do that. Essentially, image sensors have a linear transfer and they top out hard (saturate) at peak white (at the white clipping point a picket fence no loner has any detail in the whites), and at the bottom noise is a limiting factor and they can suffer a form of 'black clipping' somewhat akin to reciprocity failure in colour film) if not properly biased. Film emulsions [for a given aperture] and the human eye have better dynamic ranges, as their transfer curves are S-shaped and thus compress image data at both ends. With that longwinded lead in, it seems to me that most of our body's receptors have large dynamic ranges, essentially they use floating-point arithmetic to set dynamic range, levels etc. For example, I've been in situations where I've had to install monitoring cameras where the ambient light was highly variable, in fact up to 10^6 : 1. The human eye adapted AOK but the electronics was pretty R/S even after automatic aperture and automatic gain control compensation were wound to maximum effect.
Finally, I noticed you mentioned a matter that only the cognoscenti from specific parts of the planet understand—that of Marmite (long gone is anyone on the western side of the pond, either from boredom, or more likely from sheer disgust—and or perhaps because we've now switched to a foreign language. You obviously have some understanding of the subject or you wouldn't have mentioned it. There are many things I want to know about it, but I'll confine myself to the matter of its consistency. Can you enlighten me about that? How is it achieved? Presumably by some evaporative process but there has to be a lot more to it than that (i.e.: getting from yeast to that consistency would seem to involve many steps).
A real expert can do both. The problem is that "nice-tasting" means different things to different people, and "nice tasting" may or may not have any correlation or even overlap with "expensive". The most expensive wines I've ever had have tasted horrible, borderline undrinkable, because they have all been very old wines, which I personally don't like. But some people (apparently) like the taste of very old wines, which are rare, and expensive to produce because they (obviously) have to be stored for a very long time.
The main skill of a true wine expert is to be able to listen to someone else describe what they like and then pick a wine that matches that description or, even better, takes them just a little bit outside of their usual comfort zone.
Wines don't become expensive because they are good. They become expensive for the same reason any other commodity does; the demand, for whatever reason, exceeds the supply. There are really good wines that are cheap because they are mass-produced, and really bad wines that are expensive because they are rare, but have just enough people with more money than sense willing to buy them for whatever reason.
Even the experts, according to some studies, like the one described in the title article, or here:
https://www.theguardian.com/lifeandstyle/2013/jun/23/wine-ta...
I doubt it's reliably the case that experts will be immune to the tricks of the human brain, unless they don't own one.
>All but the experts were susceptible to this effect.
I dont understand
If people managed to "accurately scored the wines", then what does "all but experts were suspectible" actually means?