Cueing for food

When was the last time you were overcome with a desire to eat a particular food? Did you say lunchtime, dinnertime, when I was last hungry and so on? Thank you for playing - next contestant, please. We may want to eat at these times, but it’s rare for such occasions to prompt a desire for something specific. On the other hand, walking past a bakery or pizzeria or curry restaurant can easily produce a desire to consume the source of the aromas we pick up. You’ll perhaps notice that I didn’t include vegetable market or health food shop among these examples, and there’s a good reason for that.

Food sensory cues - sights, sounds (sizzling, for example), smells - are signaling not just the presence of food, but also the food’s palatability. And they are everywhere. The multimedia environment in which we are all immersed in affluent societies means that cues signaling food palatability are present for pretty much the majority of the time we are awake, through television, advertising, and our urban ‘smellscape’.

This is not to say that ‘internal’ cues such as hunger are irrelevant to motivating us to eat. Indeed, hunger makes us much more vulnerable to ‘external’ food sensory cues which mainly come about through learning. That is, our bodies associate the ingested fats and sugars of foods with their flavours and aromas, which not only becomes highly liked as a consequence but also become a powerful trigger for the desire to consume, or wanting. This desire or drive is at least as much about hedonic hunger as it is about an empty stomach (see: Learning to Want for further detail).

It is important not to underestimate the role that cue-elicited wanting plays in overeating. Obesity is much less common in societies where regular mealtimes are observed and snacking is low. It is ‘non-essential’ eating, driven by a desire for food pleasure (read: fat, sugar, salt) that provides the greatest challenge to a health weight. We are all influenced to greater or lesser degrees by external food cues, and we will all tend to eat more of a palatable food than one that is not palatable. But the fact that cues can have such a powerful impact on eating has raised the question of whether those who have difficulty controlling their food intake are somehow more aware or more reactive or perhaps more vulnerable to external cues.

Even if you find chocolate or desserts highly appealing, you may or may not give in to the temptation to indulge when either is available. The idea of eating restraint - habitual monitoring and control of food intake – seems to be important here. Food cues (the sight or smells of a pizza, or even thoughts about food) exert their greatest influence on desire to eat if you are a restrained eater – this isn’t very surprising if you consider that restraint means denying yourself food pleasures.

It is easy enough to think of restrained eaters as wildeyed and salivating, forever battling with urges to eat. But of course restrained eaters as a group must include both those who are successful at resisting these urges – successful dieters – as well as those who succumb. Moreover, even if you are not a restrained eater, you may still be someone who tends to give in to the temptations posed by the sight or smell of your favourite foods. Thus, another characteristic – disinhibition – has been implicated in determining responses to food cues. Many of us have tried to lose weight at some stage. This will often involve a considerable effort to inhibit your desire to consume the palatable foods that you will encounter. If you are effective at doing this, then you can be said to be low in disinhibition (the failure of inhibition); conversely, if resistance is futile, then you can be seen as high in disinhibition.

Irrespective of its origin, when measured on the Three Factor Eating Questionnaire (the other factors are restraint and hunger) (1), up to 50 per cent of women in the USA show high disinhibition, and this percentage is highest in young women. Estimated rates in men tend to be much lower, perhaps around 25 per cent, depending on age and other demographic factors.

Disinhibition is not just about reacting to all foods at all times. Those who show high levels of disinhibition are especially responsive to cues that signal the calorie content of foods and thus prone to ‘wanting’ highly palatable foods: sweet foods and beverages and food high in fat, such as butter, cream and ice cream. And because of the nature of the trait, they tend to act on these desires when palatable food is available and consume more. Those high in disinhibition are therefore not simply gluttons who want to continue to eat, but individuals whose responses to sensory cues are exaggerated.

Needless to say, degree of disinhibition is thought to be crucial in determining successful dieting. It is highest among those dieters who have most trouble maintaining their ideal weight and in dieters who are most bothered by food images that lead to craving. It is, for example, associated with increased chocolate intake by those who identify themselves as ‘chocolate addicts’.

To be able to understand the impact of food cues on eating, disinhibition and restraint need to be considered together. If you are low in disinhibition, it is more likely that you will be a successful restrained eater. If you are not trying to restrain your eating, then your level of disinhibition might seem to be of less concern. But if you do not restrain your eating and you are high in disinhibition, then you will still be highly responsive to palatable food cues. 

How these interactions might influence reactions to palatable foods is illustrated by a study (1) in which a group of women were offered their most tempting snack food – including chocolate, crisps, candy, nuts and cookies. The women were firstly asked to taste a small amount of the snack, and then were given the remainder to take home and asked to come back a day later. Half of the women were instructed not to consume any of the snack until they returned the next day (the temptation condition), while the other half of the group were given no instructions (the control group). On returning to the laboratory the next day, all women were offered their snack to eat and the amount they consumed was measured. Regardless of the group they were in, those who measured low in restraint or those high in restraint but low in disinhibition ate approximately the same amount as they had on the previous day. By contrast, those high in both disinhibition and restraint ate significantly more if they were in the temptation group.

The combination of restraint and a strong tendency to disinhibition therefore made these women particularly vulnerable to the temptation of a palatable food that had been restricted. This is, of course, exactly the set of circumstances that those who experience cravings report during periods of dieting. It is not completely clear as yet whether eating restraint is a risk for weight gain if you are disinhibited or disinhibition is a risk if you diet a lot. Increasingly, though, studies are teasing apart the relative contribution of these factors.

Most recently, Martin Yeomans at the University of Sussex (2) has been characterizing those high in food disinhibition, finding that their responses to food may be in fact a reflection of a more general, underlying personality dimension. He pre-exposed participants varying in both restraint and disinhibition to pictures of ‘unhealthy’ foods and measured their responses on a number of tests of general impulsivity (included a test of willingness to delay reward: $2 now or $10 next month?) and risk-taking. Although none of the tests were specifically related to food or eating, after exposure to food cues, high disinhibition women were more impulsive and higher in risk-taking. In contrast, those high in restrained eating showed no such effects, irrespective of exposure to prior visual cues.

Thus, the trend that is emerging is that disinhibition is the important personality factor that predisposes to weight gain, and this is due to how disinhibition alters your response to food cues. Consistent with this, disinhibited eaters consume far more of an available snack following a high carbohydrate meal than do those low in disinhibition. Moreover, this overeating was not driven by hunger but rather by the hedonic properties of the snack. While it might seem that asking such individuals to restrain themselves is a sensible approach, it is clearly asking for trouble, with the risk of failure being high.

 ____________________________________________

1. Stunkard AJ, Messick S (1985) The three-factor eating questionnaire to measure dietary restraint, disinhibition and hunger. Journal of Psychosomatic Research 29: 71–83.

2. Soetens, B., Braet, C., Van Vlierberghe, L., & Roets, A. (2008). Resisting temptation: Effects of exposure to a forbidden food on eating behaviour. Appetite, 51, 202-205.

3. Yeomans, M. R., & Brace, A. (2015). Cued to Act on Impulse: More Impulsive Choice and Risky Decision Making by Women Susceptible to Overeating after Exposure to Food Stimuli. Plos One, 10, e0137626.

4. Chambers, L. & Yeomans, M.R. (2011) Individual Differences in Satiety Response to Carbohydrate and Fat. Predictions from the Three Factor Eating Questionnaire (tfeq)’, Appetite, 41, 316–23.

The hot topic

A few times every year, and without too much effort, you’ll find articles about the “hows and whys” of liking for hot (spicy) foods. Most recently, there was “Learning to Like Spicier Food” and “What’s Driving the Global Chili Pepper Craze” in the USA magazines The Atlantic and Forbes, respectively [both featured conveniently in Taste Matters on Flipboard]. Now, I’d like to be able to say that these particular articles actually revealed the drivers of the chilli ‘craze’ or the exact mechanisms of chilli liking. However, scientists such as Paul Rozin attempted to answer both questions some years ago [1], but without reaching an obvious conclusion, and the same questions continue to be raised.

Chilli is not like other foods. We don’t, for example, tend to see long articles exploring the conundrum of ice cream or chocolate preferences. It’s fat and it’s sugar and they’re delicious …. what’s the issue? Chilli, on the other hand, contains compounds that, when they aren’t being added to foods, are being sprayed into the faces of criminals, students and other less desirable members of society. Indeed, the effects in both cases are not entirely dissimilar: tearing, pain, facial flushing and excessive salivation. In neither case, does our body seem to be welcoming a dose of capsaicin.

And yet …. chilli, from its origins as a relatively localized crop in central and south America, has become the most used spice worldwide, and the second most added food ingredient after salt. We can’t all be masochists, surely?  There are two questions to answer. The first of these is why any individual would voluntarily eat something that was painful. Secondly, why have so many societies – Korea, Mexico, India, Vietnam, Thailand, amongst many others – made hot spices a central part of their cuisine’s flavour principle? These are not the same question, but on a different scale. In very many societies, sections of the population eat odd things – oysters, natto, Vegemite – without such delicacies taking over the world.

A variety of explanations have been proposed to attempt to explain the ubiquity of chilli and other pungent spices (pepper, ginger, cinnamon, mustard). These include that fact that the chilli plant is a fast growing source of vitamins, especially C and A; that it increases salivation and hence better digestion of foods; and that it promotes perspiration and thus heat loss in warm climates. These all sound plausible reasons, but they lack any evidence to support them [2].

There really is no obvious connection between the cuisines of those countries that have adopted chilli, nor any obvious difference between those that are and are not especially spicy. Why Korea and not Japan, for example? Had Japan not been resistant to foreign influences until relatively recently, would its soba be spicy? Geographical isolation aside, one clue to the widespread uptake of chilli may lie in the nature of dietary staples in chilli consuming countries. In Mexico, the cuisine is based on corn, in South-East and other parts of Asia, rice – both bland staples. It may be that chilli provides a way of providing interest and flavor impact to otherwise somewhat monotonous diets.

To be convincing though, this argument needs to apply elsewhere, rather than in just warm-climate cultures and their chilli-dominated cuisines. The expeditions of Christopher Columbus to central America are widely regarded as the source of the introduction of chilli to the rest of the world. It is useful to recall why he was sailing in the first place, and that is to find a convenient route to the sources of spices in Asia. In other words, spice-wise he really was very lucky. Europe as a whole proved a tough sell for chilli, but it is unclear why. It may have been the growing climate as much as the heat of the fruit itself. Certainly, chilli is still used in countries such as Spain, Italy and parts of central Europe. Hungary, of course, took the hot chilli and converted it in hot and mild versions of its national spice, paprika. Even Britain has a history of applying other pungent spices to foods with its traditional use of hot mustard and horseradish, and now curries from the subcontinent being the most popular restaurant foods. In the USA, hot sauces are more popular than ketchup. Hence, even in countries where dietary variety is not an issue, spiciness continues to increase.

It is well known that both flavour impact and complexity in foods are valued, making foods more pleasurable. Pungency in its many forms provides both. Adding bubbles to soft drinks, heat or cooling to foods, and bite to alcohol are all ways of engaging a completely distinct sensory system, mediated by the trigeminal nerves in the tongue, palate, nose and eyes. While this system contains pain fibres, it also responds to other tactile and temperature sensations that can enhance and amplify tastes and odours. 

Even when the burn of a hot dish becomes a little too impactful, and the body produces defensive responses such as salivation and flushing – we are aware that it is harmless. In high chilli-consuming countries, the spice is introduced to children gradually in the secure context of family meals, and there is therefore no anxiety associated with the pain. 

Another piece of evidence supporting idea that chilli is used for flavour impact is the change in response to the burn over time. Regular chilli eaters do show a reduction in burn intensity, but this is minor, and they are not immune from the burning sensations – rather, they actually learn to enjoy them, even if it seems too hot at first [1]. Interviews with both Americans and Mexicans who were asked why they liked chili showed that the majority referred to the piquancy, or the enhancement of flavor of food. Many interviewees claimed to be as sensitive as always to chili, but that they had come to like the hot sensation that they originally disliked. This is also consistent with a view that chilli consumption represents “benign masochism” – effectively getting enjoyment from pain because we know it is harmless. 

A variety of explanations have been put forward to explain the high levels of enthusiasm with which many of us take to very spicy food. It is no surprise to find that real chilli enthusiasts are also “sensation seekers” for all sorts of sensory stimulation. One enduring popular notion is that the burn of chilli releases the body’s own opiates, or endorphins, perhaps via the release of a neurotransmitter called Substance P (which is released in response to pain). The idea is that chilli eating – followed by a little squirt of the body’s own heroin – produces a feeling of well-being could reinforce a sort of spice addiction. Attempts to demonstrate this have yet to produce any evidence for such a mechanism, but it is at least consistent with findings that chilli burn is reduced by sweet tastes, and vice versa [3]. The pleasantness of sweet tastes are also thought to be mediated by endorphins, and it is well known that sweetness can increase tolerance for pain [4].

___________________________________________________

1. Rozin, P. and D. Schiller, The nature and acquisition of a preference for chili pepper by humans. Motiv. Emot., 1980. 4(1): p. 77-101.

2. Prescott, J. and R.J. Stevenson, Pungency in food perception and preference. Food Rev. Int., 1995. 11(4): p. 665-698.

3. Prescott, J., S. Allen, and L. Stephens, Interactions between oral chemical irritation, taste and temperature. Chem. Senses, 1993. 18(4): p. 389-404.

4.     Barr, R.G., et al., The response of crying newborns to sucrose: Is it a “Sweetness” effect? Physiol. Behav., 1999. 66(3): p. 409-417.

Nose-ology of smelling

Just how important is our sense of smell? None of us wants to lose any of our senses, but ranking them in order of importance will for many people put smell into the lower half of the list. This is certainly reflected, for example, in compensation payouts where the lost of an eye, or partial deafness, is weighed far more heavily than total smell loss. Such figures are worked out in a world in which survival no longer depends on sniffing out our daily meal. But I wonder if, in the developed world at least, old ideas about the importance of smell have not kept pace with our recent obsessions – both nutrition and flavor related – with food.

It has been obvious for some time that the key to flavour characteristics is a food’s aromas. The OED, for example, notes that the word flavour in English, thought to date from the late 14^th/early 15^th century, originally referred only to a fragrance or aroma. A figure of 80% is often quoted as the contribution that odours make to food flavours. This is not based on actual data, but is rather an attempt to convey smell’s importance. Less quantitative, but more to the point, is the fact that with our sense of taste alone we are generally unable to identify foods and beverages – as we often witness when the sense of smell is disabled by nasal congestion. From the point of view of flavour, a food without an odour is no more than a nutritional supplement.

Knowing this, you might think then that our sense of taste is the one to loose (if we had a choice) and wanted to continue to enjoy food. It is fortunate, however, that total taste loss is relatively rare since when it occurs its effects are reported to be at least as, if not more, devastating to food enjoyment as is smell loss. 

In contrast, major smell loss is relatively common and is associated with a wide variety of social and health problems, including loss of enjoyment of food leading to altered eating patterns, depression, and increased concerns about hygiene and household safety. Interestingly, while the acquisition of a sensory loss of any type might be expected to produce such effects, it has been reported that individuals who have never had a sense of smell also report many of these problems [1]. Compared to healthy controls, a group of such congenital anosmics reported more household accidents, increased concerns about social interactions, and higher depression scores. Their eating behavior was, however, similar to that of the normosmic controls. This suggests that dietary changes following smell loss are primarily due to a lack of interest in foods as a result of their sudden ‘tastelessness’ or attempts to overcome this problem by, for example, boosting flavor using salt or sugar or other detectible qualities.

Smell loss is also common as we age, although it appears that this often goes unnoticed because of its gradual onset, while eating patterns are preserved due to habit. In fact, suddenly acquired total smell loss does not always produce a dramatic impact on food choices. As with aging, this may reflect the preeminent role of habit in the diet of some individuals. However, first hand reports of those suffering anosmia acquired as a result of head injury or nasal disease include examples of individuals who say that they can recall food flavours and essentially “fill in the gaps” left by the lack of food odour.

The ability to generate such olfactory imagery has been somewhat contentious, but there is now good evidence that some people can generate mental images of odours, even if they tend to be more fleeting and weaker than visual images. So-called good olfactory imagers – based on self-report – actually sniff when imaging odours, and their sniffs are larger (more air inhaled) when imaging good than bad odours, exactly what is found with sniffs in response to a physically present odour [2]. Imagined odours have recently been reported to enhance the ability of a food picture to induce salivation, and to influence the actual amount consumed of a palatable food [3]*. An earlier study found that imagined odours enhanced a physically present congruent taste in the same way an actual odour would [4].

So, olfactory imagery can have tangible effects and this is important since olfactory cues are very powerful engagers of food wanting and craving.  Variations in being able to image a food flavor may therefore be crucial to understanding why some individuals succumb to food-related cues by overeating. 

In addition, though, why only some people are able to generate olfactory images and indeed why it is possible to use these to compensate for actual smell loss highlights how surprisingly little we still know about the nature of the information about smell that we store in memory. We know that odour memories seem to be more emotionally laden than other sensory memories. They are also poorly linked to language – no one has the same difficulty identifying a melon by sight as they do in naming it based only on its odour. 

In a recently published theoretical review, Koster and colleagues [5] propose a model of the sense of smell that attempts to account for the apparently odd ways that smells are encoded. These authors point to the fact that, generally, we are mostly unaware of the odours around us – indeed, for most of us, most of the time, our environment is odourless. After a brief period of perception, even novel odours recede out of consciousness due to adaptation. However, this does not mean that that the odour is not encoded. Koster and co argue that odours are ignored without consequence because the encoding is implicit – odours link to events and places incidentally, without conscious effort. The meaning of the odour is supplied by the context in which it was originally experienced. They argue, too, that not only is there no point in asking questions about our ability to identify odours, but that attaching a name to an odour necessarily weakens the link between the odour and its initial context. It is only when an odour is experienced in an unusual context or when expectations about odours are violated do we need to conscious pay attention to them since this may signal something potentially important to survival.

All this may seem odd: that our sense of smell is more about ignoring odours than paying attention to them. However, as Koster et al. note, sensory signals are meant to tell us something important about the world. Information that indicates only that the status quo is in place tells us nothing, while attempting to consciously take in and process such information would be overwhelming. 

Surely though this doesn’t apply to food? We think about food enjoyment in terms of attending to the myriad odours and flavours that make up our diet. But, do we actually do this? A meal at a gastronomy temple may encourage a focus on individual flavours and odours, but did you really pay attention at breakfast today? And exactly what was the quality of peas-ness of your peas last night? On the other hand, if there was an odd flavour lurking in your greens, you can be assured that this will register and possibly help you avoid consuming something nasty.

* This article is notable for one other thing: introducing the worst neologism in recent memory ….. smellizing.

_________________________________________________________________

1. Croy, I., et al., Learning about the functions of the olfactory system from people without a sense of smell. PLoS One, 2012. 7(3): p. e33365.

2. Bensafi, M., S. Pouliot, and N. Sobel, Odorant-specific patterns of sniffing during imagery distingusih 'bad' and 'good' olfactory imagers. Chem. Senses, 2005. 30: p. 521-529.

3. Krishna, A., M. Morrin, and E. Sayin, Smellizing Cookies and Salivating: A Focus on Olfactory Imagery. J. Cons. Res., 2014. 40: p. DOI: 10.1086/674664.

4. Djordjevic, J., R.J. Zatorre, and M. Jones-Gotman, Effects of Perceived and Imagined Odors on Taste Detection. Chem. Senses, 2004. 29: p. 199-208.

5. Koster, E.P., P. Moller, and J. Mojet, A "Misfit" Theory of Spontaneous Conscious Odor Perception (MITSCOP): reflections on the role and function of odor memory in everyday life. Front Psychol, 2014. 5: p. 1-12.

Flavour terroirism

It is difficult enough attempting to define the key influences underlying any flavour (see, for example, TasteMatters, July 2012: Driving a better tomato), but wine seems to be in a category all its own. Wine is chemically complex, but so are many foods and beverages we consume each day. What really sets wine apart (although some products such as cheese do come close) is its immersion in an artisanal mystique. The craft of winemaking resists scientific analysis, and this is particularly true of Old-World wines. After all, if winemaking was ‘just’ science, then any wine course graduate could plant vines in a paddock somewhere and 3 years later – hey presto! – Chateau Cheval Blanc ’47!

What really sets wine making apart is, of course, the land. In attempting to understand what makes a good cornflake, debates about the role of the soil in which the corn was grown are relatively uncommon. But the idea of terroir is now so entrenched in our appreciation of wine that its influence is taken for granted. The characteristic qualities of the land – the amount of clay or minerals in the soil or the local micro-climate – are seen as crucial to understanding not just the ripening and health of the grapes used in the wine, but the flavour of the wine itself. In essence, the wine flavor becomes an expression of the soil. This is sometimes taken to extremes, with the flinty character of a white wine being derived from the flinty soil, for example.

Beyond the romance of the idea of terroir, there are some practical reasons for linking the land to the flavour of the wines it produces. Thus, accepting this link means accepting too that wines from one region will in most cases taste quite different from those of another region, even if all other factors – grape variety, wine maker, storage type and so on – are kept constant. This is important, both for marketing purposes and for establishing that certain flavour characteristics are typical of a region and hence deserving of protected status. In turn, the idea of terroir underpins the rationale for using organic, or even the slightly whacky biodynamic, practices. It means too that the final say in what a wine tastes like cannot be left to consumer demands or market forces since the winemaker operates under constraints of the soil, and the soil determines what the wine ought to taste like.

Some of the attempts to study terroir have provided little support that this is an especially large contributor to flavour. In a descriptive sensory analysis of German Riesling wines from a number of wine estates, Fischer et al. [1] noted the huge variation in sensory properties among wines from the same vineyard, suggesting that terroir was a relatively minor influence on flavour, compared to the major influence caused by vintage and wine estate. They cite another study published in German by Wahl & Patzwald (1997) in which the researchers went to the effort of transplanting seven different soil types to the same vineyard to study the impact of soil type on wine composition and sensory quality of Silvaner wines. They reported no significant impact on wine ̄flavour of the soil type, beyond different grape yields.

In fact, a scientific analysis of the impact of terroir has proven difficult. Not only do soil types and climate vary with geography, but of course so do other factors including such things as the location of the vines relative to drainage and sunshine. Even when two locations have a winemaker in common, the entrenched belief by the winemaker in the influence of terroir may be an explicit or implicit source of handling the grapes or the wine in different ways.

Recently, Cadot et al. [2] surveyed wine producers from the Anjou region of the Loire in France to determine their concept of wine (flavour) typicality and how they thought that it related to terroir. Not surprisingly, for these producers, the main characteristic that explained both typicality of the wine and its flavour was the terroir. Soil and climate characteristics were important for 93% of the wine producers (compared to 65% for wine-making practices and 5% for harvest quality). The winemakers’ judgments of what constituted a typical wine of this region (and hence what was the main influence of terroir) were sensory attributes such as colour intensity, red fruits, and soft tannins.

In contrast, a descriptive sensory evaluation of the region’s wine produced a profile of the ‘perceptual typicality’ of the wines. Here, visual descriptors, spiciness and astringency, but not red fruits or soft tannins, were important. Moreover, when it came to those factors that distinguished the more prestigious style (Anjou-Villages Brissac) from a more quaffing variety (Anjou Rouge), only those technical factors under direct control of the winemaker - maturation time, vatting time, harvest date, and proportion of the Cabernet Franc grape – were influential.

Similar conclusions were drawn from a study undertaken some years ago by one of my students at the University of Otago, Sara Springhall [3]. Sara asked 27 experts/semi-expert wine tasters (all either teaching enology, undertaking enology courses, or members of wine clubs) to taste 13 Chardonnay wines sourced from three distinct regions in New Zealand - Hawkes Bay, Marlborough and Central Otago. According to http://www.winesofnz.com, these regions are characterized respectively as having (a) high sunshine hours and variety of soil types; (b) Lots of sun, cool nights, low autumn rains and free draining alluvial soils; and (c) hot, dry summers, snowy winters, and soil structures that are very different to those of New Zealand's other regions, with heavy mineral deposits in silt loams.

The tasters were asked to sort and group the wines based on similarity of flavour and then provide descriptors for the most prominent sensory characteristics. The sorting data were analyzed by using the number of times that wines were grouped together as a measure of their “distance” from one another. This allowed the data to be represented as a multidimensional map, which showed both substantial overlap between regions (Central Otago and Marlborough) as well as clear separation (Central Otago and Hawkes Bay). The axes of the map (essentially, North-South vs. East-West) were shown to be related strongly to the common descriptors for the wines. The major axis, the one along which the wines differed most, was found to be associated positively with the woody and caramel attributes of the wines, and negatively with the wines’ sourness. Variations in wine citrus flavours were associated with the secondary axis.

These axes were also strongly associated with the chemical characteristics of the wines. In particular, alcohol and sugar content varied positively with the main axis of the map, while pH correlated negatively and volatile acidity positively with the minor axis.

What all these data mean is that both sensory attributes and chemical characteristics underpinned the ways in which the wines were sorted. However, since the wines grouped according to geographical regions were not strongly aligned to either the sensory or chemical dimensions on which these wine experts sorted the wines, the data suggest that the most important influences on the flavor of these wines occurred during winemaking. Woody and caramel qualities, for example, generally originate as a result of contact with oak during fermentation and maturation, while variations in citrus flavours, alcohol and sugar content are linked closely to when the grapes are harvested.

A failure to reveal the impact of terroir does not mean that there aren’t better or worse soils or microclimates in which to grow grapes that make good wines. But it does mean that we ought – for the moment – to be sceptical about wine producers’ claims that wine flavours are to any great extent a product of the soil. Alternatively, you can accept the claims, because of the romance of the idea …. but to be consistent, it’s probably a good idea to start asking your bartender about the soil in which the hops were grown next time you order a beer.

                                                                                                                       

1.         Fischer, U., D. Roth, and M. Christmann, The impact of geographic origin, vintage and wine estate on sensory properties of Vitis vinifera cv. Riesling wines. Food Qual Pref, 1999. 10: p. 281-288.

2.         Cadot, Y., et al., Characterisation of typicality for wines related to terroir by conceptual and by perceptual representations. An application to red wines from the Loire Valley. Food Qual Pref, 2012. 24: p. 48-58.

3.         Springhall, S., et al. Multidimensional sorting applied to understanding flavour variations in Chardonnay wines in 5th Australasian Association of Chemosensory Science Annual Scientific Meeting. 2002. Heron Island.