Monday, May 29, 2023

How could any wine-lover deny the idea of terroir?

Terroir is apparently an endlessly discussed topic in the wine industry, so why should I not throw in my 2-cents worth? So, that is what I will do, here.

As I looked outside my window back in March, at the farm-field across the road, I could see the snow lying to different depths and melting at different rates, even within this single field, depending on the orientation of the land. At this latitude (mid Sweden), it matters whether the field slopes south (towards the sun), or north (away from it), or even east or west (morning sun versus evening sun). This effect of local climate conditions is just blatantly obvious.

Do these sorts of differences affect the crop that grows on this field? Well, that seems to depend on what that crop is — for some crops it does seem to matter. Grapes are one crop for which there is a strong claim that it matters quite often, although the nearest commercial grape-vines to my house happen to be 2 hours’ drive away (Blaxsta Vingård; see: Swedish wineries — who'd have thought it?). *

This concept of local variability, whether caused by climate or geology, is often called by its French name: terroir. (Wordnik: The aggregate characteristics of the environment in which a food or wine is produced, including regional and local climate, soil, and topography.)

Mosel valley terroir

I should start by noting that in the science of ecology this variability is called local habitat, and it is a basic concept. All plants and animals, and also microbes, have a habitat. Sometimes, a particular species has a very broad habitat, covering thousands of miles, and sometimes it is incredibly restricted, covering less than a mile. Nevertheless, as an ecological scientist I have always accepted the concept of each species having a habitat as being self-evident.

The most widespread species on Earth is Homo sapiens; and humans seem to be determined to demonstrate that they can live anywhere, under any conditions — but we do have to wear different clothes and live in different types of houses, depending on where on the planet we are at any given moment. Most other species cannot afford this luxury, and so they have to live where the local habitat happens to suit them. For example, we often hear about the local weather, and its effect on grape growing — things such as this (The ocean phenomenon shaping great SA wines): “Occasionally we see the phrase ‘maritime influence’ come into play, where regions and vineyards close to our coastlines are affected by sea breezes, which can cool and moderate temperatures during the grape ripening seasons.”

However, while weather is a big overall determining factor for plant growth, it is not the only thing that affects plant habitat. I have always assumed that grape-vines have a habitat, even if the wine industry calls this idea “terroir”, instead. That habitat may be different for different grape-vine cultivars, and the habitat may affect those cultivars in different ways; but that just means that the wine industry is clearly and inextricably linked to nature. The basic question of interest to us, then, is: does the terroir affect the taste of the resulting wine, as well as affecting the growth of the grape-vines themselves?


A classic example of the discussion of terroir is that of Bordeaux (Terroir and climate of Bordeaux, Dirty little secret about the soil):
   The terroir of Bordeaux is more than just the soil. There are a variety of factors to consider that create the special terroir of Bordeaux. For example, the climate with its weather, exposure to sunlight, ambient temperatures in the air and in the soil, elevation, natural drainage, access to water, the ability of the soil to retain water in the dry vintages and allow for natural drainage in the wet seasons.
   Those are some of the most important elements that change how a grape will ripen, develop and taste, due to the soils and terroir of Bordeaux. All of those possibilities alter the performance of the vines and the grapes in every vintage.
On a more personal note, my wife and I, many months ago, tasted the: Celler de Capçanes collection called la Nit de les Garnatxes, which is 100% grenache from Tarragona (Spain). It consists of one bottle of wine made from each of four different terroirs: Argila (Clay), Calissa (Limestone), Llicorella (Slate / Schist), and Panal (Sand). Trust me, they are all quite different wines (we had the 2015 vintage). Even if you don’t trust me, then you can read brief notes of a tasting by Thomas Girgensohn (Grenache, four ways).

Mind you, we should not go too far. Alex Maltman, a geologist and winegrower, is the author of Vineyards, Rocks, and Soils: The Wine Lover’s Guide to Geology (2018). In his book he reminds us that: “Any mineral solutes present in wine ... exist at levels well below the threshold for detection” (p. 158). He thus urges an end to the persistence of words in tasting notes referring to rocks and other minerals in the literal sense. Similarly, we should not ignore the obvious human influence on both grape-growing and wine-making (Wine, terroir and the human touch).

Farm crops are constrained by the local geology

On a bigger scale, according to the Alcohol and Tobacco Tax and Trade Bureau (TTB), there are 147 American Viticultural Areas (AVAs) in California alone (Established American Viticultural Areas), about half of which are supported by regional winery and grower associations (Are AVAs important to the wine industry?). We might treat each of these as potentially having a distinctly different terroir, given that they are recognizably different from each other. For example: “It’s all about the location of the vineyard with microclimate, soil composition, depth, aspect to the sun, and elevation all playing a major role in the quality of the wines” (Napa cab still matters). Such things continue to be quite important in the wine world, as we also see in other U.S. states (eg. 7 New AVAs in nontraditional winegrowing states), as well as elsewhere (Chianti Classico’s new subzones: shining a light on diverse terroir).

There is plenty of online literature on the concept of terroir, and how to detect and apply it in the wine world, much of which is quite easy to read:


In a past life, I taught Australian university students about plant environmental biology, which is the relationship between plants and the immediately surrounding environment in which they grow. As I noted above, this is simply the scientific equivalent of teaching them about terroir. To me, it is therefore professionally impossible to be a terroir denier.



* Actually, the nearest recently planted half-hectare of vines is only 20 km away (and thus it is currently the most northerly vineyard in Sweden).

Monday, May 22, 2023

The Wine & Spirits Magazine Top 100 wineries

There are many lists handed out each year, telling us about some sort of rank-order of wines and/or wineries; e.g. Drinks International magazine: The World’s Most Admired Wine Brands (What is a "most admired" wine brand?). One potential problem with such lists is that they tend to change each year (see: The Most Admired Wine Brands are very different this year). However, these sorts of lists are often fun to look at, anyway.

Each year, Wine & Spirits Magazine unveils their Top 100 Wineries of the Year (currently: Announcing the Top 100 Wineries of 2022). This is the list that I will look at here.

The list of wineries is compiled as determined by “their exceptional performance in our tastings this year”, based on “vetting thousands of producers via the magazine’s exclusive two-step blind-tasting process.” This process has been described in more detail in: How a ‘Top 100 Wineries’ list actually happens: a peek behind the scenes.

Since the wines tasted vary from year to year, and you can look at each individual list of wineries for yourselves, I will instead look here at the consistency of the wineries in the lists across several years. There is no necessary connection between these winery—years, because each list is based on the wine scores solely for that year. Nevertheless, if winery quality means anything, then the same wineries should get listed each year (provided that their wines were tasted), even if their order changes.

The first time the magazine produced a Wineries of the Year list was way back in 1987. However, let’s start by first looking at the past 9 years only — this should provide a list of [some of] the currently prominent wineries. There were 427 wineries listed in at least one of these 9 years. The number of times they were listed were:

    No. years    No. wineries
        9                2
        8                2
        7                11
        6                11
        5                15
        4                32
        3                49
        2                68
        1                237

So, only two of the wineries were listed in all nine years; this is not too good, if we are looking for consistency. The 26 top-listed wineries were as shown in this next table.

Top wineries of the past 9 years

Most of these wineries come from California (8), followed by Italy (5) and Oregon (4). To me, this seems to be more than a little bit biased, geographically speaking.

If we now look at the previous 26 years, the list is quite different, as shown in this new table (below). This shows the number of times the top-listed wineries appeared (only those that appeared in at least half of the yearly lists), and compares this to the recent 9 years. As you can see, only Concha y Toro, Penfolds, and Marchesi Antinori did well in both sets of years. That is, the current Top 100 wineries are not the same as they once were; perhaps we should not really be surprised?

Top wineries of the past 35 years

This means that we should now look at all 35 years, simultaneously, if we want an overview of the past 3½ decades. This is shown for the most successful wineries in the figure below. In this case, a dot means that the named winery was listed in the Top 100 in that year.

As you can see, only 9 wineries appeared in at least half of the yearly lists. Penfolds topped the score-sheet (29/35 appearances), followed by Concha y Toro (27/35). Of these top nine wineries, Penfolds, Concha y Toro, Chateau Ste. Michelle, Ridge Vineyards, Marchesi Antinori and Iron Horse did consistently quite well (across the years), whereas Boutari and Louis Jadot did well only in the early years, and Diamond Creek Vineyards did well later.

Top wineries of the past 35 years

So, there you have it. These apparently are the top wineries, in the world, according to the annual wine tastings of Wine & Spirits Magazine. I have no objection to any of them being in the list; but I can think of one or two others that should be there, as well. I am sure that you can, too!

Monday, May 15, 2023

Is Artificial Intelligence right for the wine industry yet?

The answer appears to be: Continue to be careful, just at the moment.

Actually, this has been a good fortnight for the media, with regard to Artificial Intelligence (AI), hasn’t it? Several groups of the originators of this form of computing have come out of the shadows, warning all of us about the potential dangers of letting commercial companies develop this sort of computer activity unsupervised. Two good introductory discussions include these:
Way back in 2018, I published this blog post : Artificial intelligence in the wine industry? Not yet, please! Since then (2020), I have asked: Should we worry about Artificial Intelligence in wine writing? In this current blog post, I will return to the overall topic, by writing about some of the potential general problems of AI, just in case the wine industry tries to get too involved without understanding what they are doing (eg. How AI will be a game-changer for the wine industry).


The whole idea of AI is precisely what its name says — trying to develop a computer version of natural intelligence. The idea is that, if our own brain cells can be intelligent, then so can computer circuits. The basic issue is how to actually go about arranging this.

One common approach these days is called “machine learning”. The basic idea here is that we give the computer massive amounts of what we think is information relevant to some topic, then let the computer troll through it all, looking for common patterns. The computer then uses these patterns to produce apparently “intelligent” responses to future situations, by regurgitating what it deems to be the most likely response. Somehow, this is meant to mimic what human beings learn to do as they grow up.

Unfortunately, this is not quite how we do it, as there is a basic contradiction here. AI simply finds a consensus in a massive block of data, which comes from the past; but this does not necessarily say anything about the future. So, one part of the process is talking about changing things for the future, while the other is about automating access to information from the past. Maybe these are connected, and maybe they are not — this is what we are doing when we say: “I will have to think about it.”


Let’s start by looking at a couple of the absurdities that can be produced by this computerized process. My erstwhile correspondent, Bob Henry, once tried asking Bard about me and my blog. Bard is described by its creator, Google, as a “conversational AI model” (“a machine-learning breakthrough”, no less!). The response Bob got from Bard was this:
     David Morrison is an American astronomer, a senior scientist at the Solar System Exploration Research Virtual Institute, at NASA Ames Research Center in Mountain View, California. He is the former director of the Carl Sagan Center for Study of Life in the Universe at the SETI Institute and of the NASA Lunar Science Institute. He is the past Director of Space at NASA Ames. Morrison is credited as a founder of the multi-disciplinary field of astrobiology. Morrison is best known for his work in risk assessment of near Earth objects such as asteroids and comets.
     The Wine Gourd wine blog is a website that provides information about wine, including reviews, recipes, and tips. The blog was created by David Morrison, a wine enthusiast and educator. The Wine Gourd blog covers a wide range of topics related to wine, from the basics of winemaking to more advanced topics such as wine tasting and pairing. The blog also features reviews of wines from around the world, as well as recipes and tips for pairing wine with food.
     The Wine Gourd blog is a valuable resource for anyone interested in learning more about wine. The blog is well-written and informative, and it provides a wealth of information about wine. The Wine Gourd blog is a great place to start if you are new to wine, or if you are looking to learn more about this fascinating beverage.

Clearly, the first paragraph is about someone other than me; and the second paragraph is a load of nonsense. I quite like the third paragraph, though! Still, I would not rely too much on Bard, just at the moment, if I was you.

Another absurd example comes from here in Sweden. A national supermarket chain asked ChatGPT (another AI-powered language model, this time developed by OpenAI) to produce a recipe for an Easter cake. All that ChatGPT did was throw together a lot of the foods associated with Easter, as shown in the picture below. This haphazard cake did not go down well with the customers — it was disparaged as “Egg in green grass”.


Actually, it is often ChatGPT that generates the main discussion of problems, or else other chatbots. There is little point in me going into details in this blog post, so here is a list of reading for you:
In addition to all of this stuff about chatbots, there are many other concerns, as well, such as:
To counter-balance all of this negativity, there does seem to be enormous potential, if we can only get things right. So, here is another list of reading, for you:


I conclude that the answer to my title question does appear to be: Not just at the moment, thankyou.

Now, maybe I am just a Grumpy Old Man, bemoaning that the world is changing around me, at a time when I would like to slide into a quiet old age. However, I have lived most of my adult life throughout the Computer Revolution, and so I’ve seen too much unjustified hype before, and I am therefore not so easily fooled any more.

A suitable analogy here is guns and gunpowder (the latter was introduced to Europe from China). These were used to feed us at first; but so-called “bad actors” quickly learned to use them for attacks on humans, instead. This started off small, but gradually increased, with hordes of horseman sometimes streaming in on placid settlers. Then the guns became cannons; and then the powder became part of bombs. Eventually, we developed nuclear weapons — this is a long way from a few single-shot rifles. So, at that stage we backed off pretty quickly, because not every product of the human mind is necessarily in our own best interest, globally. As a young man I was very glad about that, because the alternative future looked pretty bleak to me, back in the 1970s. Furthermore, we can easily detect when someone detonates an atomic bomb, but we currently have no idea what AI is doing behind the scenes.

Anyway, all that Machine Learning does at the moment is take huge amounts of data, and then searches for patterns in it, which it regurgitates upon request (Can today’s AI truly learn on its own? Not likely). There is more to intelligence than this. To me, the success of chatbots simply shows us how many lonely people there are in the world. Chat with your friends, instead; and if you don't have any, then use your own intelligence to learn how to make some, rather than relying on the artificial kind. However, all of this does not mean that AI is not useful, for many tasks.

Fortunately, at least some politicians are apparently listening (White House says it will look at AI regulations, legislation): their basic principles are said to include the need to “evaluate, verify, and validate the safety, security, and efficacy of AI systems.” We shall see!

Monday, May 8, 2023

Success and failure of visits to winery tasting rooms

There have been a number of recent reports about problems getting visitors to come to winery tasting rooms (cellar doors), at least in the numbers that they were in before the Pandemic (e.g. Tasting room visitation is down). I have wondered: is this a bad thing, or not? After all during the Pandemic, because wine enthusiasts weren’t allowed to travel, many wineries went to them, instead, online (How Sonoma County wineries are navigating a post-pandemic tourism world). This makes for a different direct-to-customer future, but not necessarily a worse one. *

Mind you, I do like visiting wineries. So, these thoughts have prompted me to wonder about the quality of the winery-visiting experience before the Pandemic. One potential source of such information is the user reports compiled by the travel-planning site TripAdvisor. To this end, a report in 2022 used this source to examine: What went right and what went wrong in my cellar door visit? Here, I will look at some of the conclusions from this report.

Wine tasting room at Granite Hills

The authors were interested in what they call Service Quality (SQ), which derives from comparing perceived expectations (E) of the service to perceived performance of that service (P), so that SQ = P—E. That is, Service Failure is defined as service performance falling short of customer expectations.

To look at this quantitatively, the authors note that:
According to the rankings on the TripAdvisor platform, based on the number of reviews, the top five wine destinations in the world are: Tuscany (Italy), followed by Napa Valley (the USA), Hunter Valley (Australia), Stellenbosch (South Africa), and Mendoza (Argentina).
So, these are the five regions that the authors studied, using what they describe as a combination of “sentiment analysis” and “natural language processing”, as applied to 89,672 TripAdvisor reviews (from Jan 2010 to Apr 2021). ** Their analysis divided these into Positive reviews and Neutral/Negative reviews, which allowed the authors to identify what they perceive as both the Service Quality components and the Service Failure components. The review comments associated with these two groups turned out to be:

Service Quality:
wonderful tasting experience
knowledgeable friendly staff
interesting informative tour guide
good / nice wine
small family winery

Service Failure:
rude people / staff
worst winery tour
poor customer service
bad / terrible experience
disappointing visit

From this analysis, the authors concluded that: “the issues most linked to service quality and service failure are as follows (in order of importance):
the quality of the main wine product,
the experience in the tasting room,
the organized tours,
the empathy of the staff,
the reliability of the staff, and
the setting of the cellar and landscape.”

So, now you all know what to focus on when visiting a winery (or when people visit your winery).

Service success versus service failure

The authors also noted that these themes were common to all five wine-tourism regions. However, there was also some notable difference between the regions, if we look at the final (overall) scores assigned for Service Quality versus Service Failure. These are shown in the above graph, where each point represents one of the regions, mapped with its Quality score horizontally and its Failure score vertically (which is negative, of course).

As you can see, four of the regions follow a simple pattern of inverse relationship between Quality and Failure (shown by the red line) — Quality declines as Failure increases. On the other hand, the Napa Valley, has the least Service Failure score while still not doing all that well on the Service Quality score (ie. second last) — there is some disconnect here between Quality and Failure, which would be worth exploring further.

However, in all five cases the Quality scores are greater than the Failure scores, which is what we want to see in the wine industry. Unfortunately, the authors do also note that customers are more likely to remember service failures than remember excellent service.

Regarding differences between the regions, the authors note that: “Tuscany, and especially Stellenbosch, are characterized by the complementarity between wine and food, and Mendoza, Napa Valley, and Hunter Valley by the presence of organized tours.”


There is nothing necessarily negative here, even in the failure aspects. After all, it should simply “remind us that our greatest lessons are those learned from failure, and that sometimes these lessons are hard won” (quoted from: How engineers learn from failure). So long as we are always trying to do better, then we will learn from both success and failure (for a hint on success, check out: The best thing you can do to prepare tasting room staff for the busy summer season).

Personally, I have enjoyed every one of my winery visits, to one extent or another, whether in Australia, the USA, or Europe. This has enriched my life, obviously!



* This in addition to the environmental factors that affect winery visitation, from time to time (e.g. NSW wineries at breaking point from decimated crops, declining tourism after floods), as well as the effects of Climate Change (e.g. Queensland's wine industry calls for stronger action on climate change after horror season of hail, flood and fire).

** I have used TripAdvisor a lot in the past, when my wife and I travel, and so I am well aware of its limitations, and especially its biases. So, the data here do need to be interpreted carefully.

Monday, May 1, 2023

Assessing the carbon impacts of wine production

In a recent Wine Gourd post (The wine with the worst carbon footprint in history?), Paul Vandenberg (from Paradisos del Sol Winery) left a comment pointing out that glass bottles are actually responsible for a fair part of the carbon output of wine-making. Indeed, the Wine Institute in California has estimated that glass bottles account for at least 30% of wine’s carbon footprint.

This is clearly a very serious issue, and so I will go into it in more detail in this post. I will do this by focusing on the grape-growing and wine-making parts of the so-called Production Life Cycle (PLC), rather than either the retail or end-of-life PLC phases.


Conveniently, the Australian Wine Research Institute (AWRI) has recently published a Life Cycle Assessment (LCA) as applied to Australian wine production (Understanding the greenhouse gas emissions of Australian wine production). * This study calculated the greenhouse gas outputs associated with the production and distribution of Australian bottled and cask wine. This is an excellent source of information, which can also be applied to the wine industry globally.

As noted in the report:
Life Cycle Assessment (LCA) is a method for assessing the environmental impact and performance of a process or product in terms of its greenhouse gas emissions or carbon footprint. LCAs are generally either ‘cradle to grave’ — considering all impacts from extraction and processing of raw materials, energy production, use, recycling and disposal — or ‘cradle to gate’ — considering all impacts only until the product leaves the producer.
The LCA process actually requires complex mathematical modeling, in order to produce estimates for a typical (“average”) example of the product concerned. In this case, the initial data, as used for the modeling, were collected from 38% of Australia’s total vineyard area, plus wineries covering 43% of the total Australian production. Various features of the grape-growing and wine-making processes were then estimated from these comprehensive data.

The report concludes that the average ‘cradle to grave’ carbon footprint of Australian wine in 2022 was calculated to be 1.05 kg CO2 equivalent per L. However, most importantly, this varies dramatically depending on the type of packaging used. This is shown for four possible packaging types in this first graph. As you can see, bottles do not fare well, compared to bag-in-box distribution (called a “cask“ in Australia, which is the word used in the following graphs).

Fig. 5 from AWRI report

This becomes even more important if we add in the carbon expense of exporting the wine. The next figure shows that the carbon emissions of bottles delivered domestically is pretty much the same as the carbon emissions of exporting wine in bulk, because the packaging costs (glass) balance the transport costs (ships). Exporting wine in bottles is therefore the worst-case scenario. So, for the wine industry the big issue is, indeed, packaging, not either grape-growing or wine-making.

Fig. 1 from AWRI report

Next, the report compares the carbon emissions associated with Australian viticulture as compared to Australian wineries. The immediately preceding graph shows that grape-growing and wine-making have very similar carbon footprints to each other (ie. it is packaging and transport that has the biggest effect). Indeed, an earlier study from the AWRI concluded that grape-growing contributes 15% to the CO2 in a bottle of wine and wine-making contributes 17% (Understanding carbon emissions in the wine industry). This rough equality must be a social relief to both the grape-growers and the wine-makers.

However, the origins of their carbon emissions are very different between the two parts of the Life Cycle. As shown in the graphs below, both electricity and diesel fuel make up 70% of the carbon load for grape-growers, whereas electricity alone makes up 70% for wine-makers. Clearly, electric tractors, for example, might go a long way towards helping grape-growers (Electric tractors are rolling out in the field).

Fig. 3 from AWRI report

Fig. 4 from AWRI report

Anyway, I recommend that you take a look at the original report for yourselves, even if you don’t live in Australia. The situation is probably not very different compared to where you do live. Furthermore, the report estimates are interestingly compared for 2022 versus 2016 (with a nice improvement through time!). The second report that I mentioned above also has an interesting discussion of collecting the CO2 released during fermentation, and then re-using it for other purposes, which would be a positive contribution by the wine industry towards reducing atmospheric CO2.

There is a further discussion of issues in this article: The carbon economy and vineyards — what’s the status quo? After all, the future will involve reducing carbon emissions, so we might as well start now, as discussed here: Decarbonising wine: sector strategy to tackle emissions.



* Published in the Wine & Viticulture Journal Issue 2, 2023 pp. 34-37. The illustrations in this post are taken from that publication.