Wine, ideology and quality

Particularly in recent months this topic has been on my mind a lot, as I have been drinking more natural wines, thinking about them, and listening to what others have to say. I’ve been wanting to write about it for a while, but couldn’t quite find the right angle. I’m still not convinced, but here goes…

I totally understand that people like the idea of organic and biodynamic viticulture – that it is less harmful to the environment and vineyard workers for example, and results in better wine. I certainly do not agree on all points, but I see where they are coming from. Similarly with natural winemaking. Absolutely there are moral issues associated with wine production, and there is also the possibility that more ethical forms may lead to better-tasting end product.


However. I am increasingly getting the impression that the ideological sense of the word good is getting conflated with good as an indicator of quality. For some, if a wine is ideologically good then it tastes good, and if it does not conform to their worldview then it tastes bad. Not merely because ideology and quality are correlated, but almost as a matter of definition. This ideological quality, as I shall call it, has nothing to do with the smell and taste of the wine, its price, the environment in which it is served, or any number of other possible factors, but is almost exclusively dependent on the ideology of how it is produced.

I was being deliberately coy when I wrote “getting the impression that” at the top of the last paragraph, because it is difficult to find direct and unambiguous quotes. But when you hear some people talking about natural wines the implication is clear. The well-known proponents of natural wines may be a little more guarded in what they say, but by the time these ideas filter down to their followers the message can be a lot more blatant. Some really do believe that anything made with zero percent sulphites is delicious and everything else is crap.

Let me be clear that I am very aware that many lovers of natural wines do not espouse this ideological quality. And actually I am not even necessarily criticising those that do – I just find it an intriguing phenomenon that I am struggling to understand. In many ways it would be surprising if ideology did not colour our judgement of quality in a wine, but for me the shocking aspect is how massive the influence can be.

The idea of ideological quality seems at the moment to be most closely associated with the natural wine movement. But it can be broadened. There is for example the excellence of all wines awarded 100 points by [insert name of favourite wine critic here]. If it seems too far-fetched to regard points as being part of an ideology, just remember Parker’s rhetoric about the democratisation of wine. Also, stretching the concept of ideological quality possibly a little too far, some drinkers seem to worship wines only from the classical regions of France, while others make a virtue of drinking wines from more out-of-the-way regions, and from rare grape varieties.

I absolutely don’t want to tell you which wines you should like, and why. But I do firmly believe we should develop a greater awareness of why we like the wines we do. In that awareness lies the route to greater vinous enjoyment.

More on aroma perception by sniff and sip

I am again writing here about comparing orthonasal and retronasal olfaction – smelling things through the nostrils, compared with through back of the mouth. If having two modes of smelling is a new concept for you, you might like to refer to an earlier post on the subject where I explain it in more detail. I started to get interested in the subject when I realised that a number of studies on wine aroma perception only looked at orthonasal olfaction, i.e. sniffing the wine, and wondered how much difference it would make if retronasal olfaction was studied instead. One of those studies was the relatively well-known one where a red dye was added to white wine, leading tasters to describe it in terms of red wine aromas (Morrot, Brochet and Dubourdieu, 2001, The color of odors, Brain Lang, 79 , 309-320). Another was a series of studies with the conclusion that we can reliably identify a maximum of four aromas in a multi-aroma mixture. Reading the recently published books by Gordon Shepherd and Jamie Goode has given me a few new insights, which I shall share here.

The most general point is that the smell of a wine is never perceived in isolation. It is part of what we might call the wine’s overall flavour, and it is impossible to totally separate smell from what we perceive through other senses. With retronasal olfaction, we are simultaneously tasting the wine on our tongue, and also feeling it in our mouth as possible astringency and alcoholic heat. Orthonasally, the interference from other senses is maybe less obvious, but we before we sniff the wine we still normally see it, and that affects expectations. This was in fact the point of the Morrot et al experiment mentioned above. Additionally we can also experience chemicals in our nostrils through our sense of touch, for example as alcoholic heat, or the pungency of hydrogen sulphide. These non-smell sense modalities are not only confusable with smells, but they can also affect our sensitivity to true smells

We should also note that we never smell the wine itself, but the volatile molecules that escape from it. In the glass, however much we may swirl and sniff, we have relatively little control over how the volatile molecules escape and reach our nasal cavity. But once in the mouth, the processes acting on the wine can be complex, and vary a lot from time to time, and person to person, even if we are largely unconscious of what is going on – the wine is mixed with saliva, warmed towards body temperature, moved around the mouth to a greater or lesser extent, and allowed to coat the mouth and throat, and its molecules enter the nose when we breathe out.

Then, there are the effects of background smells. You can become so used to a background smell that you no longer notice it. Normally this is an advantage when it comes to wine tasting. It will, for example, filter out the smell on your hands of cigarettes or mildly scented soap. But what if that background smell also happens to be a component of the wine? IN that case your desensitisation to the background smell will affect how you perceive the wine. There is also the possibility of cross-adaption, where one odour affects your sensitivity to other one. The most obvious example is perhaps how the TCA of a corked wine mutes its fruity aromas. If background smells may be important from the environment, retronasal olfaction must be affected by non-wine smells inside your mouth. Apart from the possible remnants of lunch, coffee and cigarettes, there are also the normal odours of your mouth and throat to consider. Unpalatable to think about perhaps, but perfectly natural, and a potential source of desensitisation and cross-adaption when tasting wine.

There have, by the way been a number of studies that have concluded that odour detection thresholds are higher for retronasal that orthonasal olfaction – in other words that we are more sensitive to smells when sniffing through our nostrils. But we need to be careful about drawing false conclusions from these results. In the experiments, the samples are presented to subjects as gases containing an odour, through a tube that goes either to the nostrils or to the back of the mouth, so it is difficult to see what direct relevance these results have to wine tasting.

Finally I would draw your attention to a 2006 study, not discussed in the above-mentioned books, that pursues the question of how many flavour components we can identify in a mixture, but unlike earlier studies that have looked at orthonasal olfaction alone, this one concerns how we perform with a liquid in the mouth, and involves both odourants and tastants – things we detect using both the nose and taste buds. Thus, it is more applicable to the question of how many component we can detect when tasting wine. I won’t give a detailed description of the results here, but just mention that they were very much in line which the findings of the orthonasal olfaction studies. To quote from the authors: “In conclusion, the present study has shown that humans have great difficulty identifying the components of odor–taste mixtures when more than two components are present”.

In summary, I would say that there are many potential reasons why orthonasal and retronasal olfaction might lead to different perceptions in wine tasting, but it is still far from clear how important the differences are in practical terms.

Neuroenology, and I Taste Red – two book reviews

Here I review two recently published books that cover similar ground. Both describe the science of how we perceive wine. As is made abundantly clear in both books, we use all our senses in wine perception, not just smell and taste, and we integrate this information in our brain, together with memories of other wines, and what we think we know about the wine, to create the impression of what the wine “tastes like”. It is an important point.

Both books were worthwhile reading for me, and yet I found both annoying in places. They are a nice pair of books to read at roughly the same time, as Jamie Goode’s is written from the perspective of a wine writer who has read up on the science of tasting wine, while Gordon Shepherd writes as a neuroscientist making research findings relevant to wine lovers. As you might expect, the books are very different in style.

First off, let’s take a look at I Taste Red: The Science of Tasting Wine, by Jamie Goode. I got it for £10.77 including postage from Books Please, who seem currently to have the best price for books – well below Amazon prices. If I buy the book myself, I always quote the street price rather than the usually irrelevant RRP.

This is a generally very readable book, which will appeal to a lot of wine lovers, and covers the ground well, with a good emphasis on the importance of multimodal perception on wine tasting.

In my opinion though, some of this readability was at the cost of understanding the basis for a some of the information we are presented with. Jamie did explain that, in order to make the book more accessible, he did not want to include references in the text, but this meant I that I was unable to check out the evidence for a few statements that I thought questionable. In a similar way, Jamie did tend to talk about things that were assumed by wine experts as if they were facts, and I think a more critical examination of the assumptions would have been good.

Sometimes, I felt that the ground was covered a bit too broadly, in that the topics strayed well away from wine tasting, into the importance of smell for sexual attraction for example. It was interesting in a way, and I am sure deliberate, but I would have preferred a bit more focus.

Another criticism – and this seems to be increasingly common in wine writing, and journalism in general – is that there was a lot of reporting of what other people say and think, with little analysis and reflection. I would like to have seen more of an attempt to establish a consistent and reasoned view of where the truth lies.

Get this if you want an accessible book that has a broad mainstream overview of the subject.

Now on to Neuroenology: How the Brain Creates the Taste of Wine, by Gordon M Shepherd, also bought from Books Please, this time for £13.85.

This book is tougher going, reflecting perhaps that it is written by a neuroscientist, and there is a lot more hardcore science, which might put off a lot of people. It starts at a ponderous pace, mainly telling us what we are going to be told about later, but picks up momentum as you get into the book. I found most of it clear, but I did get a bit lost trying to follow the pathways of information in the brain. I think I took a wrong turn at the Amygdala. Perhaps clearer diagrams might have helped? As with Jamie’s book, there is no formal referencing system, but I felt the informal system in this book would by-and-large make it possible for me to chase up the original research if I wanted to.

This book covers the ground very well too. Perhaps in a bit too much detail in places – I am not sure, for example, that we really need to know so much about the aerodynamics of the inside of the nose. In other places however, the detailed scientific explanations are both relevant and fascinating.

The author does not pretend to be a wine expert but he has clearly spoken to some, and one in particular: Jean-Claude Berrouet of Petrus, the meeting with whom is described in an interesting appendix. But I do wonder if that meeting was a little too influential in the image of The Wine Professional painted in the book. A lot of professionals taste a lot more informally than Gordon describes.

And in a way, that leads on to a general gripe. Gordon is always at pains to emphasise the importance of each stage of wine perception – from the first sight, sniff and sip, through the mouth and nasal cavity, and within the brain – but there does not seem to be any attempt to get a handle on the relative importance of all these factors. Thus, as everything is soooo important, the wine taster is advised to do all manner of things to get the maximum sensory input from the wine. However, I am far from convinced that this turning-up-the-volume approach is a good idea when tasting, and think that it may finish up emphasising aspects of the wine that are far less noticeable when drinking properly, and not necessarily in a good way. I personally have discovered, for example, that swilling young Barolos round the mouth causes the astringency to mask the fruit, which is more evident under normal drinking conditions.

You may not know, but the same author also wrote a book call Neurogastronomy, which I reviewed a few years ago. So one obvious question is: should I buy Neuroenologly if I already have the older one? And if I were only to buy one book which one should I get? While they share some material, they are very different books. Neuroenology being very much organised around tasting wine. It certainly would not hurt to get both books, but if you really want only one, I would say wine lovers should get the older Neurogastronomy. But do note that this is a big thumbs-up to Neurogastronomy, rather than a strong criticism of the new book. You might have to do a bit more work to relate it to wine, but Neurogastronomy gives a bigger picture, some of the additional information being relevant to wine too.

How big are your bubbles?

In the pre-Christmas dearth of news, when all serious journalists seem either to be at their Christmas parties or on their way home for the year, comes the widely reported story that champagne is better with bigger bubbles. This assertion is based on a study by Prof Gérard Liger-Belair that is due to be published in the European Physical Journal Special Topics next year.

I cannot get my cyber hands on that precise article, but I am guessing it was the research published earlier this year as a Nature Scientific Report, which states that “Finally, we exhibit conditions on bubble bursting that optimize aerosol evaporation: large bubbles and weakly viscous liquids. We identify a large bubble radius (~1.8?mm), broadly common to the whole range of champagne viscosity, that makes liquid transfer more efficient. […] This result is also remarkable as it undermines the popular belief that the smaller the bubbles, the better the champagne.” A popular belief, eh? I suppose so. But it is also one that Liger-Belair supported back in 2003: “Our ultimate goal is to create smaller bubbles in champagne wines.” According to that older article, the “reason smaller bubbles make better champagne is basically because there are more bubbles available to release the flavour and aroma”.

Absolutely no shame for a scientist to change his mind as new evidence comes to light – science progresses. But this shift of emphasis points to many more fundamental questions about what makes a good Champagne. It is quite possible that in the ideal case you want more bubbles, and bigger ones. But given that a bottle of Champagne can only hold so much carbon dioxide we cannot have both, so where should the balance lie? And do you want them all soon after pouring, as well you might if you a toasting with your glass of Champagne, or do you want them to be released slowly so you can enjoy it over a longer period? Presumably there are also limits to the benefits of aroma-releasing bubbles. However much you enjoy the Champagne aromas, you don’t want your drink splattered all over your nose in a violent eruption of bubbles.

And all the discussion so far seems to assume that aroma intensity, as detected by sniffing, is the most important aspect of Champagne quality. Putting aside the other important quality aspects of wine, such as balance, length and complexity, and sticking with the subject of bubbles, my understanding is that the texture of fine bubbles in the mouth is one of the hallmarks of a good sparkling wine. And however much aroma big bubbles might release into the glass, they supposedly give an inferior mouthfeel.

But enough of this geekery. There is a lot more to the enjoyment of Champagne, or any other sparkling wine, than can be achieved by obsessing about bubble size. And most of the enjoyment has nothing to do with what you learn on a wine course. It’s the occasion, and the people you drink it with. Have a good Christmas, and enjoy whatever is in your glass!

Minerality in wine update

The discussion, or debate as many would like to see it, about minerality has moved on tahconsiderably since my post on the subject back in 2012, as evidenced by the Institute of Masters of Wine seminar about a month ago, which has been particularly well reported by Emma Symmington. The term is still abused, often in marketing, and there are still those who will gleefully rant against those abuses, but there seems to be more of a consensus developing amongst those who have given the term serious thought. If I may presume to represent that more serious thinking for a moment, let me attempt to summarise the consensus.

santorini-mineralityThere are at least two scientific meanings for the word mineral, which often get conflated and confused. As far as the geologist is concerned a mineral is a naturally occurring chemical compound, and rocks are agglomerations of different minerals. However, in plant biology, minerals (shorthand for mineral nutrients) are ions that are taken up from soil by the roots, e.g. nitrates and magnesium ions. The naïve interpretation of minerality in wine is that compounds from the rocks underneath the vineyard get taken up by the roots of vines, and finish up in the grapes, where they contribute directly to the flavour of the wine. Thus vines on chalky soils result in chalky wines. This is wrong for a number of reasons… Firstly, the vast majority of rocky minerals do not taste of anything. Secondly, the ion minerals in the soil do not principally originate from the chemical compounds in the rocks. Thirdly, plants tend to take in what they need of each mineral and then stop, so high soil mineral contents are not reflected in the vines and grapes. Finally, in the concentrations found in grapes, the minerals are below our taste detection thresholds. Rocks and minerals might have indirect influences on wine flavour, by affecting vineyard drainage for example, but it would stretch my credulity to breaking point if someone suggested that those influences lead to wines that taste of the rocks in the soil.

mineralsI hope there is nothing too controversial in the above, because I would now like to set it aside and move along to say that even if minerality in wine has little physical or chemical basis, it can still be used as a metaphor. That, I think, is the broad consensus view on minerality, and an excellent basis to take the discussion forward.

Metaphors can be beautiful, evocative and poetic, and if that is what you want in a tasting note who am I to argue? But tasting notes are also used to communicate. Person A experiences a wine and tries to describe those experiences in a tasting note. Person B reads that note, and imagines what the wine must taste like, perhaps to help with a buying decision. How good are metaphors in general  for this sort of communication?

When we say a wine has pear drop notes, we of course don’t mean it contains pear drops – it just tastes like pear drops, which is arguably a very straightforward simile rather than a metaphor. If we don’t understand what it means, we can suck on a pear drop. What is more, even if the wine does not contain pear drops, it probably does contains isoamyl acetate and ethyl acetate, which also contribute to the flavour of pear drops.  This is similar to how quite a number of wine descriptors function, and in those cases it seems to me that the chances of good communications are relatively good.

But when we say that a wine has good minerality, how does that work in communication? To communicate in the way I described above, the writer and the reader must have a common understating of the term. Many wine geeks say they understand exactly what it means, but the problem is that there are many different understandings, and very diverse ones at that. From comments in various wine forums, I note that for some it is an aroma, for others a taste or a texture sensed in the mouth. Clark Smith in his book Postmodern Winemaking is a bit left field in describing it as “an energetic buzz in the wine’s finish, almost like an electrical current running through the throat.” Personally, I use it for a positive aspects of a wine that are neither vegetal nor animal – often for a certain something that is very closely related to acidity and sulphur. This lack of common understanding was also commented on by the participants at the minerality seminar mentioned above, and nicely illustrated by the graph in Emma’s report. As she writes, “So if a group of MWs can’t agree on what minerality is, means, or tastes like – what hope do consumers have?”

I conclude simply by suggesting that the term minerality does not work well in communicating what wines taste like. I would hate to dictate what descriptors may and may not be used in tasting notes, as communication according to my definition is not everything. But isn’t it an important factor? You decide.

Why four’s the aroma limit

four aromas

I recently had an article published in Circle Update (the magazine of the Circle of Wine Writers). It concerned the number of aromas used in wine tasting notes. If you are interested you can view and download a PDF offprint of the article here: Why four’s the limit.

It draws heavily on a four-part series of blog posts I wrote late last year. Compared with the Circle Update article, these contain more words – not necessarily a good thing – but also, in “the science” post, there is considerably more information about the scientific basis for the notional limit of only four aromas being identifiable in blends.
How many identifiable aromas in a wine – the dilemma
How many identifiable aromas in a wine – the science
How many identifiable aromas in a wine – tasting experience
How many identifiable aromas in a wine – my conclusion

How smell is like vision, and what that means for wine

Considering the very different impressions that vision and smell make on us, there are surprising similarities in how the two senses are processed before they reach the brain. And it is quite possible that these similarities may throw some light on how we describe the aromas we find in wine.

The olfactory bulb (we actually have two of them) is an elongated protuberance lying close to the underside of the brain, but attached only at the back end. The surface of the human olfactory bulb has on it some 6,000 spherical bundles of cells called glomeruli, each one being connected by neurons to several thousand olfactory receptors in the nasal cavity. When odorous compounds enter the nasal cavity, each glomerulus is activated to a greater or lesser extent, creating a pattern of activity on the surface of the olfactory bulb that is a representation of the odours detected. That pattern can be regarded as analogous to the pattern of activity on the retina of the eye when an image falls on it. In fact the similarity does not stop there, because just as the image on the retina is further processed to facilitate detecting edges and motion, the activity pattern in the glomeruli is also enhanced by subsequent layers of cells in the olfactory bulb. Examples of smell images, reproduced from Gordon M Shepherd’s book Neurogastronomy (reviewed here), can be seen below – click to enlarge and make the text legible.smell images

In the same book, Shepherd proceeds to speculate that the smell images created by glomeruli activity are similar to visual images of faces. He suggests that this explains why smells, like faces, are difficult to describe in words but relatively easy to recognise. As a result, if asked to describe a smell we need to resort to comparisons with the smells of well-known objects. Also, neither smells nor faces are processed as the sum of distinctive component parts – we tend to recognise both of them holistically, not so much by the detail as by a general impression, and the relation between the parts of the image. Only occasionally can we recognise a face if we only see a small part of it, and usually only for faces we are very familiar with.

This speculation of Shepherd’s can be plausibly taken even further, and related to how we recognise and describe wines. Regardless of whether we are nosing a complex wine or sniffing a single chemical compound, at one level in our perceptual system the result is a glomeruli smell image. I would propose that, in the case of wine, certain aspects of that smell image may remind us of the smell images of other objects – blackcurrant maybe, or lemon – which then become the descriptors we use for the wine. In some cases, the aspects of the smell image that cause us to identify other objects in wine may arise from chemical compounds in common, but this need not necessarily be the case and similarities might be coincidental. The aspects in common may be as simple as discrete fragments of the smell image, or possibly with their root in common relationships between different parts of each image. To continue with the face analogy, the identifying of blackcurrant in a wine could be like saying that a baby’s face has his grandfather’s eyes – the eyes need not be identical, but there is however something that seems somehow similar, perhaps the relationship between the eyes and the nose. Something else that has a counterpart in wine is the idea that if we are very familiar with a face is it easier to recognise it from a partial image. In a smell image of wine, presumably the types of fruit etc. we may recognise in it are only partially represented, and that could explain why it we are more likely to recognise the aromas we are more familiar with, either from the experience of the actual fruits or from other wines.

I totally accept that most of this is speculation on the part of Shepherd and me, but nevertheless I think how we experience and describe wines is consistent with the idea of smell image recognition, and an interesting way of conceptualising it. Only time and more research will be able to refute or support these ideas.

Tasting order and wine scores

It is well known that your perception of a wine is affected by what was tasted immediately beforehand. This is similar to how other senses behave. If, for example, you sit in the dark for several minutes and then expose yourself to normal daylight, it seems to be exceptionally bright until your eyes adjust. With wine, if the previous wine was flabby, your current wine will tend to taste sharp; if it is was very dry, then sweet, etc.

anon_flight

However, in addition to that effect, the order in which you taste wines can help determine how much you like them. I have already written about Antonia Mantonakis’ research, where she presented sequences of wines to consumers, and asked which wine they liked best. In actual fact the same wine was offered in each glass, but the tasters still expressed a preference. For shorter sequences (2 or 3 glasses) they tended to prefer the first wine tasted, while for longer sequences (say 5 glasses) they preferred the last one. If you are thinking “that just goes to show how little the average consumer knows about wine”, you should be chastened by the fact that those with better wine knowledge were even more prone to this bias. But how much practical significance does it have? The consumers were after all asked to distinguish between identical wines, and they may have thought any differences were very small.

Later work[1] by French researchers throws more light on this order effect. Here the experiments were performed on wine professionals  tasting in competitions that awarded medals to Beaujolais Nouveau wines. Here, in each of two competitions of around 400 wines, approximately 100 tasters scored wines on the 100 point scale, each taster being given two flights of between 10 and 12 wines. But into each tasting sequence of wines registered in the competition, the experimenters added the same wine (an unregistered one) into the first and penultimate positions. For each competition, the average score for the penultimate wine in the sequence was greater than that for the first wine: 82.99 vs 79.78 for one competition, and 83.93 vs 81.78 for the other. Those differences are not only statistically significant, but also significant from a practical point of view. To get some feel for the practical significance, note that the difference between a silver and gold medal winning scores is 6 points. Also, as the required score to achieve a silver medal was 81, in one of the competitions the position of the wine would have decided whether the wine received a bronze or silver medal.

If wine scores and medals are important to as a consumer, then you should probably be concerned about the sequencing used in tasting flights. On the other hand, if you do not pay much attention to such things, you can now add order effects to the list of reasons that justify your position.

[1] Carole Honoré-Chedozeau, Jordi Ballester, Bertrand Chatelet and Valérie Lempereur, “Wine competition: from between-juries consistency to sensory perception of consumers”, BIO Web of Conferences 5, 03009 (2015)

Solid evidence for terroir influence on wine flavour

I recently stumbled across what seems to be solid evidence for some effects of terroir on wine. It is not new research, but for some reason it had managed to elude me, and was only brought to my attention by John Winthrop Haeger’s book Riesling Rediscovered. The research is published in [1] and [2] – see end of this post. As the latter reference is available on Google Books almost in its entirety, that was my main source of information and where I found the figure shown below.

Twenty-five different Riesling vineyard sites were studied: 12 in the Pfalz, and 13 in the Mosel, Ahr, Nahe and Rheinhessen. The substrates yielding the soils of these sites included limestone, sandstone, greywacke, basalt, slate, porphyry, and breccia from the rotliegend age. The vintages 2004, 2005, 2006 and 2007 were assessed 8 months after the harvest by panels of 13-20 trained judges. The grapes were picked at optimal ripeness, as determined by the estate owners, one portion from each site being vinified as normal by the estate, and one portion subject to a standard winemaking protocol that was the same for all sites. The wine made by the estate was evaluated in duplicate, while standard process wine was evaluated in triplicate.

The results of a discriminant analysis are shown below (click on the figure to get a larger version). If I understand the point of a discriminant analysis correctly, it here means that two functions of the flavour profiles, F1 and F2, were found such that wines of the different rock types cluster when F2 is plotted against F1. Thus, if you know the flavour profile of the wine, you could calculate F1 and F2 and stand a good chance of predicting the rock type by checking where the point lies in the left hand graph.riesling_terroir_differencesNecessarily, there were many details omitted from the conference paper, so it is difficult to judge the quality of the research, but to me nothing stands out as being obviously flawed and I would assume the work is sound. As such, for me it is the first convincing evidence for the soil substrate type having an impact on flavour profile. All the other evidence I have seen has been non-blind and anecdotal, and whenever blind tasting has been used terroir differences seem to disappear, even for people who would generally be regarded as expert tasters.

One interesting question about this research is to what extent the experimental protocol was essential in revealing the terroir effect, and to what extent it would also be clear to expert but non-trained tasters tasting blind. In other words, now necessary is the training and the discriminant analysis in uncovering the important of terroir? Also, more generally, I wonder how applicable the results are to other grapes and regions.

See my previous posts on the subject to understand my mildly sceptical attitude to terroir. I think I would still describe my attitude in the same way, but it has certainly just shifted considerably in the positive direction. However, in the introduction to the article I summarise here, it is made clear that terroir is hugely important in marketing, as a unique selling proposition, and as point of interest for punters. Marketing was the driver for this research, and whenever marketing is involved my bullshit detectors start twitching with heightened sensitivity.

[1] Andrea Bauer et al, “Authentication of Different Terroirs of German Riesling Applying Sensory and Flavor Analysis”, in “Progress in authentication of food and wine”, pp 131-151, American Chemical Society,Washington, DC, 2011

[2] A Bauer and U Fischer, “Factors causing sensory variation in Riesling wines from different Terroirs in Germany”, in “Oeno2011: Actes de colloques du 9e symposium international d’oenologie de Bordeaux”, pp 1087-1092, Dunod, 2011