Category Archives: Food Science

A Fundamental Mistake about Subjectivity in Wine tasting

06 Monday Jul 2020

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wine flavor wheelI keep seeing this inference in discussions about subjectivity in wine tasting by people who should know better.  Gordon Shepherd makes it in his book Neuroenology: How the Brain Creates the Taste of Wine, and Jamie Goode makes it in his  otherwise fine book I Taste Red. Both insist that the flavor of wine is not in the wine but in the brain.

The mistake is this. From the fact that the brain integrates a variety of multisensory signals in order to create flavor perceptions, it does not follow that the brain creates the flavors that we perceive. Flavor is one thing. Flavor perception something else just as a color is one thing and our perception of that color something else. We can sometimes make mistakes when perceiving color and we can sometimes make mistakes when tasting wine. The act of perceiving is distinct from the thing perceived.

No doubt flavor perception requires input from our sensory system and the brain. But it requires something else as well—the flavors perceived. The mistake is to think that if perceptions occur in the brain that the thing perceived must also be in the brain. No doubt we can know only what we perceive but to think the thing perceived must then exist in the mind is to conflate what I can know with what exists.

The brain by itself does not create the taste of wine. And we don’t live in separate taste worlds as Jamie Goode sometimes suggests. We may disagree about what what we taste in a particular wine but we’re tasting the same wine.

Perception is an interaction between the brain and our environment—you need both to create a perception and the object is not an empty cipher. It has real causal properties without which perception cannot occur.

The Taste of Round

29 Monday Jun 2020

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roundWhen I taste and evaluate wines, one of the most readily apparent feature of the wine is the wine’s shape and the way that shape evolves on the palate. Wines can be round, chunky, sharp, angular, contorted, flat, curvaceous, sculptured, sinuous, tapered, etc.  Wine of course is a liquid; it doesn’t literally have a shape. Nevertheless these shape words really help to characterize a wine. So what is going on here? Are these just metaphors?

Perhaps. But even if they are metaphors it remains to be explained why these metaphors can be readily understood. I doubt that people with some experience tasting wine would find it difficult to understand why a ripe Pinot Noir from the Santa Lucia Highlands is described as round or a Sancerre is described as angular. Since they are readily understandable they are likely not poetic metaphors. Their accessibility suggests there must be some literal similarity between wine and shapes.

Recent research shows that all of us are capable of making these associations. Test subjects routinely are able to reliably associate, for instance, milk chocolate with round shapes and dark chocolate with more angular shapes.

Interestingly, these cross-sensory associations appear to be transitive, that is, they extend to other associations with sounds and names (see Figure 3): Meaningless words like ‘maluma’ (Köhler 1929, 1947; Usnadze 1924, 1927) and ‘bouba’ (Bremner et al. 2013; Ramachandran and Hubbard 2001b) are matched both with more rounded shapes and, in Western populations at least, with milk chocolate. Meanwhile, angular shapes such as ‘takete’ or ‘kiki’ are matched with bitter-tasting foods such as dark chocolate. We would like to argue that transitivity is not a property of metaphors, but rather a property of sensory mappings and associations (e.g., Stevens 1966).

Spence and Deroy, the authors of the linked survey, hypothesize that the association is not purely linguistic and thus not metaphorical. There are actual perceptual interactions between the sense modalities of vision and taste.

Additional research seems to show that viewing shapes can influence what we taste.

Next, the participants were given a small piece of cheddar cheese to taste. Intriguingly, those participants who had just been looking at the angular shapes rated the cheese as tasting around 7% sharper than another group of participants who had just evaluated three organic shapes instead.

This research seems to show that there is a lot more going on in a wine than just fruit aromas. The area of cross-modal correspondences offers the potential for greatly expanding the expressive range of wine.

The Future of Meat

24 Monday Feb 2020

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cultured meatIn 2013, Mark Post, a professor located in the Netherlands, created the first burger made of cultured meat. The meat is produced in a laboratory by culturing animal cells and growing strips of muscle from them. The meat is then put on a scaffold that moves in a way that stretches the muscle thus simulating the movement of a developing living animal.

Apparently this concept is getting close to commercial viability.

Cell-based meat (also known as cultured, cultivated, slaughter-free, cell-cultured, and clean meat) could be a common sight in supermarkets across the west in the next three years, according to the Institute of the Future in Palo Alto. California-based Memphis Meats made headlines for its world-first cell-based meatballs four years ago, and is currently building a pilot plant to produce its cultured beef, chicken, and duck on a bigger scale – with plans to launch more plants around the world.

Lab meat can be produced using almost no greenhouse gas emissions, very little land, and half the energy it takes to raise conventional livestock. It needs few antibiotics and eliminates animal suffering. What’s not to like?

We will have to overcome the “yuk” factor. But it isn’t fake meat; it’s the real thing. We use cultures to propagate seedless fruit. Why not manufactured beef?

As this article points, out there are  several companies across the globe racing to scale up production at a reasonable price. One company, Future Meat Technologies, “hopes to get the cost down to $10 per lb. by 2022.”

We should probably take the timing of this with a grain of salt. I don’t think I’ve ever seen a radically new technology get off the ground on the time scale predicted by its ardent enthusiasts. Nevertheless, there is money pouring into this nascent industry and the concept has already been proven. It’s only a matter of time before “lab meat” becomes a dinner table staple.

If I were a cow I’d be very concerned about future employment.

More Insight on Spirits and Terroir

24 Thursday Oct 2019

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ryeLast week I wrote about whether the concept of terroir could be applied to bourbon. Bourbon is made with at least 51% corn in the mashbill. My hypothesis was that where the corn and other grains in the mashbill  were grown doesn’t matter much as long as the grain is healthy. What matters in bourbon production is where and how the whiskey is stored and aged. The aging process is significantly influenced by the temperature of the surrounding environment, and so place matters at least in that sense. (The use of local yeasts might also be a differentiating factor)

Kara Newman in Wine Enthusiast adds another dimension to the concept of terroir in whiskey production. Reporting on some experiments with rye whiskey she writes:

The study found that whiskey produced from Pennsylvania rye had considerably higher levels of acetaldehyde, isobutanol and isoamyl alcohol than the samples from Minnesota and Canada.

“[These compounds] contribute fruity, apple-like flavor in the Pennsylvania rye whiskeys,” says Michael Foglia, director of new product development and innovation for Wigle. “There was a quantifiable flavor difference in the whiskey made with [Pennsylvania] rye compared with whiskeys with rye from other regions.”

Even Vodka made from rye showed flavor differences despite the fact that vodka is produced through multiple distillations making it an almost neutral tasting spirit.

Most bourbon has a significant amount of rye in the mashbill to add spice so, if these experiments with rye receive more confirmation, it may be that terroir will emerge as an important concept in bourbon production.

Among all the grains used in whiskey production, rye is the most intensely flavored. It remains to be seen whether corn, barley and wheat show similar regional differences.

The Myth of the Myth of Minerality

13 Monday May 2019

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rocks in the vineyardVicki Denig writes a balanced article on minerality despite an ambiguous headline and a misleading introduction. Entitled “Nailing the Myth of Minerality”, she introduces the post by asserting “Minerality is perhaps the wine industry’s most overused, underwhelming, and misunderstood descriptors of them all.”

What’s wrong with this? For starters, “minerality” isn’t a myth; it’s a metaphor. And it’s neither overused nor underwhelming. She gets the “misunderstood” right but it’s misunderstood in part because of headlines like this. Happily she interviews enough somms and winemakers who routinely use the term and find it useful, so in the end the post leaves the impression that minerality is “a thing” as she calls it.

“Minerality” is a general term we use to describe wines that exude aromas such as flint, crushed rock, wet stone, or sea breeze or that have textures of chalk, hard stone, gravel or a kind of electrical snap on the finish. Since it is clear from tasting notes that many, many wines have these features, and they are highly prized among some wine critics and winemakers,  I don’t see what is “overused” or “underwhelming” about the descriptor.

The whole controversy really comes from some scientists talking out of school. Scientists have definitively shown that minerals in the soil do not transfer to the vines or fruit, and many (although not all) scientists use that fact to berate wine writers who use the term to describe wine. But although the fact that soil characteristics are not transferred to the wine is an important and interesting scientific claim, it is entirely irrelevant to the question of whether the term “minerality” is a useful or accurate descriptor.

We are not literally tasting rocks in the wine anymore than we are literally tasting cherry, peach, or barnyard soil in the wine. Most wine descriptors are metaphorical. Wine literally tastes like grapes; there are no cherries, peaches, or soil in your wine. These are all metaphors. But that fact has little to do with whether these descriptors are useful or accurate.

No doubt there isn’t a precisely established definition of “minerality”—it’s a metaphor!  (Sorry for screaming) While still “living”, a metaphor will not have a precise definition. That is why metaphors are useful—they flexibly and creatively pick out properties for which there is no literal description.

Denig quotes geologist Brenna Quigley who, to her credit, actually does seem to understand the usefulness of the term.

The science is quite clear that the vine is not literally picking up minerals from the soil and transferring them into the wine,” she explains, adding that this does not mean that experiences that tasters may have and describe as minerality do not exist.

This is exactly right.

This “controversy” would go away if a few more scientists had paid attention during English class. We should listen to scientists when they talk about science. When it comes to language we should listen to people who write and talk for a living.

(I suspect, by the way that Denig’s headline, is deliberately ambiguous. Is it the association of minerality with mythology that is being nailed or the allegedly inappropriate use of the term “minerality”? It is a clever headline. Apparently, Ms. Denig paid attention in English class.)

Confusion Over Reduction in Wines

28 Thursday Mar 2019

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confusedVicki Denig performs a valuable service by explaining one of the new wine buzzwords—reduction. Unfortunately, the winemakers she interviewed weren’t quite on the same page.

“Reduction” is not really a new term. Reduction refers to a wine that has been protected from oxygen exposure. The phenomenon has been around since winemakers have been adding sulfur or leaving wine on the lees without racking. (It’s called reduction because the wine or juice molecules in the absence of oxygen are gaining an election thus making the overall charge more negative.)

Winemakers now use the term frequently because more and more winemakers are practicing reductive winemaking as a way of preserving fresh fruit expression, and so it has crept into the wine lexicon as a way of explaining what is going on with a wine.

It had always been my assumption that wines in a reductive stage smell like garlic, matchsticks, or in extreme cases rotten eggs or burnt rubber. (Happily the effect usually goes away when oxygen is introduced so we typically don’t get rotten eggs in our Chardonnay)

Unfortunately, winemakers themselves (at least the ones quoted in the article) seem to be confused about which aromas indicate reduction.

Rajit Parr of Sandhi Wines says,

Reduction happens due to fermentation, it’s a byproduct. So minerals can make an affect on it, but it’s not a smell of minerals. When people say ‘Oh yeah, this wine has a lot of minerality’ because it has reduction, that’s an incorrect statement.”

But then:

In Central Otago, Francis Hutt, winemaker at Carrick Winery, also supports positive reduction. For him, great examples tend to show stone, flint, and “semi-industrial” flavors.

Hmm. Stone and flint are rather common descriptions of mineral aromas at least as that troubled term “minerality” has been used recently. [Most minerals don’t have an aroma; it’s a general term used to indicate anything rock or gravel-like in a wine]

And Abe Schoener winemaker at Red Hook Winery and founder of the Scholium Project reports:

On the positive side, for Schoener, notes of roasted coffee, chocolate, dark and savory notes, to notes of rocks, hot stony surfaces, ocean, and even notes of animal excrement, can bring positive, layered characteristics to a wine.

Coffee and chocolate I thought were oak derived aromas. Animal excrement, aka “barnyard,” is a “brett” derivative. Rocks and sea breeze, again, we’ve been classifying as minerality.

So is the take home point that we should be using the term “reduction” instead of “minerality”?  That won’t fly because lots of wines smell of rocks that are conventionally made, without reduction.

So after reading this article I am more confused than ever. It’s the job of philosophy to confuse readers; not journalism.

Coming Soon to a Future Near You

18 Monday Mar 2019

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mosa meat

Mosa Meat Burger

The last time I checked into the progress of lab-grown meat, it was still expensive and didn’t taste so good. But times are a-changin’. Mosa Meats, makers of fine lab-grown meat, estimates the current cost to be just over $10 for a hamburger and expect it to be commercially available in 3 to 4 years.

Why lab-grown meat?

Farm-raised meat is a major contributor to climate change, resource depletion and other environmental ills. And it requires an enormous amount of land and is cruel to animals. Lab grown meat avoids all those moral and environmental harms which are increasingly a threat to the planet. We’ve been trying to make plant-based burgers that taste like meat for decades with no success so that doesn’t seem to be a viable option. Demand for meat is expected to grow exponentially, to unsustainable levels, and since it doesn’t appear we are inclined to give up meat, the only option is to make it via a process that won’t harm the environment.

Of course the big question about lab grown meat is does it taste good. According to Mosa Meats, thanks to refinements in their technology, cultured meat now tastes like ordinary meat. Of course, they might be a wee bit biased so some independent taste tests would be welcome. But they are right that the molecular structure of cultured meat is the same as meat from cows. There is no reason why it should not taste like meat, since it is indeed meat. Muscle-specific stem cells are taken from a cow and are encouraged to self-organize into muscle tissue, which is then grown in the lab, eventually finding its way to your plate. It is biologically identical to meat that comes from a cow, pig or chicken.

The biggest hurdle will undoubtedly be the “yuk” factor. A room full of oozing, bulging “flesh plants” is anything but appetizing. But have you been to a slaughterhouse recently? The “Yuk” factor objection is not really a serious obstacle. Test-tube babies are real persons, cars manufactured by robots are real cars, seedless fruits are propagated using a culturing process, so why the “yuk” factor with manufactured beef? If it’s affordable and tasty plenty of people will buy it cutting the demand for livestock generated meat and eventually sending commodity livestock farming into a death spiral.

Predictions about the timing of technological advances are always dicey. But if I were looking for long-tern investment opportunities, it wouldn’t be looking at livestock.

How Many Simultaneous Aromas Can We Detect in a Wine?

20 Wednesday Feb 2019

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person smelling wineIn Gordon Shepherd’s fascinating book Neuroenology: How the Brain Creates the Taste of Wine, he reports on some research that raises obvious difficulties for wine tasting notes that mention seven or eight aroma descriptors.

In 1989, Laing and G.W. Francis were interested in how many components a person can identify in an odor mixture…. They trained subjects to identify seven individual odors and then tested them with various mixtures of the odors. Sounds easy? …. The subjects could identify each odor separately 82% of the time, but when present in a binary mixture with one other odor, the identification fell to 35%.  With three odors, recall fell to only 14% and with four odors it fell to only 4%….

Laing and others have pursued this question in a number of studies since then—for example testing panels of expert flavorists and perfumers. The results have been similar. [151]

Shepherd suggests that the maximum number of distinct aromas we can identify in a wine is three and for most people, apparently, it’s only one or two. This obviously does not square with wine tasting practices where it’s common to identify multiple aromas in several aroma categories.

Shepherd does address this by noting that many of the properties identified by wine critics involve taste and tactile sensations along with gestalt judgments that have to do with pleasure. But that response doesn’t address the problem of wine tasters reporting more aromas than the science indicates we can sense.

I haven’t looked more closely at the methodology of these studies but Shepherd’s account of them seems misleading in at least one sense.

Shepherd seems to be overlooking the fact that wine tasters seldom form conclusions about aroma notes from one sniff of the wine. I can only speak for myself but, when I write wine tasting notes, it’s only through several well-spaced inhalations that I gain a comprehensive understanding of aroma structure. I begin by identifying one or two prominent aroma notes, then sip the wine to check retronasal impressions, and then put the wine aside for a few minutes and come back to it, checking it several times in an evening. Each time I smell I’m looking for aromas in different categories so my attentional focus shifts away from aromas categories that have already been idenfitied. The fact that only 2 or 3 aromas can be identified at one time is relevant only if the taster is in a big hurry (which they are in some contexts like wine competitions.)

In fact some of the research Shepherd reports suggests how a tasting procedure of multiple, spaced inhalations is implemented in the brain.

…when mixtures are familiar, cortical neurons treat them as synthetic objects, different from their components …After experience, the cortex has learned to treat the combinations of features constituting the mixture as a unique, complete, synthetic object distinct from the patterns of features constituting their components.

I take this to mean that once the dominant aromas are familiar, the brain treats them as a single synthetic aroma, thereby freeing up “processing capacity” to identify additional aromas. We then use memory and language to put together the holistic image of the wine. I may be able to distinguish one or two aromas in a single inhalation but subsequent inhalations provide more and more information that is synthesized via memory.

This is an argument for spending time with a wine to gain that familiarity instead of writing notes on the fly.

Lies and Moral Panic About Food and Health

18 Monday Feb 2019

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scary headlinesWho’s trying to mislead us and why?

Here is a recent story from the NY Times about the dangers of processed meat. (Thanks to Michael O’Hare for pointing this out)

We see a 4 percent increase in the risk of cancer even at 15 grams a day, which is a single slice of ham on a sandwich,” said Dr. Nigel Brockton, director of research for the American Institute for Cancer Research.
Eating a more typical serving of 50 grams of processed meat a day would increase the risk of colorectal cancer by 18 percent, a 2011 review of studies found.

From what I understand, the background rate of colorectal cancer is roughly 4%. So one natural way of reading this passage is that if you eat one slice of ham per day your risk increases to 8%. And if you eat 3-4 slices per day, a more typical serving for ham lovers, your risk would increase 18% which, when added to the 4% background rate, brings your risk to 22%. In other words, according to this literal reading, over 20% of people who eat ham, bacon, pastrami, sausage, etc. every day get colorectal cancer.

This of course is nonsense. The incidence of colorectal cancer is no where near that high. The passage is systematically misleading.

What’s going on here is that the good doctor and the reporter for the Times are failing to describe how we should understand this data. It’s about relative risk not absolute risk, as the underlying research report makes very clear.

Let me explain:

If the background rate of colorectal cancer is 4%, an increase of 4% from one slice of processed meat per day is an increase of 4% relative to the background rate. 1.04 X 4=4.16. Your risk increases by less than a quarter of a percent. If you’re in that group that has a bologna sandwich packed with 4 slices everyday, your risk increases to 18% over the background rate. 1.18 x 4=4.72. Round it up to 5%. A really nasty habit of eating 50 grams, almost 3/4 lb. of deli meat per day, increases your risk of getting colorectal cancer about 1% over the background rate of 4%.

If you really love deli meats, isn’t that worth the risk?

I’m not suggesting that people eat as much processed meat as they want or that we should ignore health warnings. The cumulative effect of too many indulgences would indeed add up to an unhealthy diet. But if processed meat is one of your few guilty pleasures, surely a 1% increase in risk is not worth worrying about.

Yet, the headline says:

Is Eating Deli Meats Really That Bad for You?

Even small amounts of processed meat increase the risk of colorectal cancer.

The story goes on to point out all the chemicals that go into processed meats and the health warnings associated with them. Nowhere in the article is the small risk effect mentioned.

One would expect that reporters and editors who work for the NY Times would be aware of the difference between relative and absolute risk. Surely doctors and researchers know the difference. They also are quite aware that most readers are not sophisticated when it comes to statistics. Yet they make no attempt to correct the potential misreading.

Rather than worrying about eating that piece of salami that is beckoning, perhaps we should worry about why the NY Times is unnecessarily scaring people. Could it be because it’s click bait and sells advertising? They wouldn’t do that would they?

The Study on Emotion and Wine Revisited

11 Wednesday Apr 2018

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emotional wineLast month I discussed a report of a new study  that showed  correlations between wine and emotions. At the time I didn’t have access to the complete study, and was relying on a helpful synopsis by Becca Yeomans. I have since been able to view the original study, which is not yet available on line. The study is fascinating because it shows that we respond emotionally to wines which potentially opens a whole new arena for wine appreciation. Yet there are some very odd results that are hard to explain as I noted in my earlier post. Now that I’ve had a chance to read the study, I wanted to revisit the conclusions to be drawn from it, although it turns out that the puzzling results remain puzzling.

The study, conducted by the School of Agricultural, Food and Biosystems Engineering at the Universidad Politécnica de Madrid in Spain, consisted of a sensory evaluation of several wines by a trained panel in order to identify the organoleptic properties of the wine and a  consumer evaluation of the same wines accompanied by an emotion response analysis. The wines evaluated were a Verdejo, Chardonnay, a rosé made from Garnacha, two Rioja Reserva level wines, one from 2012, the other 2013, and a Ribero del Duero Reserva from 2012.

The consumer panel consisted of 208 students of various ages, and roughly equal cohorts of men and women, whose only qualification was that they consumed wine at least once a month. After a warm-up flight, they were given wines in a random order to be judged according to how much they liked the wine and then were given a list of 26 emotion words from which to choose the emotions elicited by the wine.

Here is a summary of the results

  • 22 of the 26 emotion terms showed a significant correlation with the wines.
  • “good”, “happy”, “joyful”, “mild”, and “pleasant” were associated with fruity and floral aromas
  • aromas/flavors of vanilla, clove, and licorice were associated with “aggressive” and “guilty”.
  • Astringency, the drying sensations caused by tannin, was associated with “aggressive”.
  • Subjects grouped wines differently based on sensory analysis vs. the emotion analysis.
  • Men and older adults scored the emotion words higher than women or younger adults but women were more discriminating regarded the emotions elicited.
  • Young adults scored the two white wines and the rosé higher for the emotions “good”, “happy”, and “pleasant”; the 2013 Rioja Tempranillo scored lowest on these emotions for this cohort.
  • Older adults identified “mild” as the distinguish characteristic between the white wines, rose and the 2013 Tempranillo.
  • Negative terms such as “guilty” or “worried” were more prominent for younger adults.

The gender and age differences are interesting but I have no idea how to explain the results so I will ignore them.

I have no training in reading statistical analyses so I’m not sure I have a sophisticated understanding of the paper. But here is what I find puzzling.

If I’m reading the charts correctly, liking a wine was positively correlated with the positive emotions. But the negative emotion terms such as “aggressive” or “guilty”  were associated with aromas of vanilla, clove, and licorice, and with astringency. These are all descriptors associated with big, red wines such as at least some Tempranillo. The positive emotions were associated with white wines.

But surely we can’t conclude from this that tannic, red wines with vanilla and clove notes are unpopular because they evoke negative emotions. I looked up data for wine sales in Spain and they show a decided preference for red wine especially Tempranillo which is the signature grape of Spain.

The consumers were asked to assess their degree of liking a wine before identifying the emotions so these results can’t be easily explained by the emotion biasing the judgment about the wine’s likeability. The only explanation I can come up with is that consumers outside the laboratory don’t make the connection between likeability and emotion. Only in the laboratory when the test subjects know they’re expected to make the connection is the association salient thus leading the subjects to have an experience unlike that of ordinary consumers.

But there is one more hypothesis that is worth mentioning. The authors of the study state,“If a wine conjures up negative emotions for an individual, that person is probably not going to buy that bottle of wine in the future.” Whatever the relationship is between wine and emotion, I doubt that wines “conjure up” emotions. As I have argued elsewhere the association between wine and emotion is typically metaphorical. We associate astringent wines with aggressive emotions but they don’t make us feel angry or afraid. It’s an association, not a direct causal relationship between the wine and an emotion. “Conjuring up” may be the wrong way to describe this relationship. Similarly, a piece of music may express anger or fear, but we don’t feel angry or afraid when listening, and it’s that expression that we find enjoyable despite the fact the emotion may be classified as “negative”.

If in conducting the test, the experimenters were encouraging  the study participants to think of wines as causing emotions rather than metaphorically expressing them, their experience of the wines might be quite atypical. A wine that causes one to feel aggressive or guilty might indeed be unpleasant; a wine that expresses aggression or guilt might be interesting.

I have no idea how much plausibility to assign either of these explanations.

On the surface, the study seems well done and the results are certainly interesting. But the fact that the results of the study seem to contradict what we know about wine preferences means that much more work will have to be done to tease out the factors that explain this relationship between emotion and wine.