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Terroir: A Matter of Difference

My profile of Château Lafleur posted earlier this week contains a lot of information on the terroirs – or at the very least the soils – of the Lafleur vineyard. Reflecting on my recent visit to meet Jacques Guinaudeau and look at this very special Pomerol vineyard got me thinking about terroir, how people use and interpret the word, and whether or not there were any other possible explanations for what we call terroir.

When I first became aware of the concept of terroir, the prevailing view was that it was something overtly detectable in a wine. For instance, at a Château Talbot tasting I attended many years ago, a taster with far more years and much more tasting experience behind him than I had leaned back in his chair and sighed “ahh…. the gôut de terroir…. lovely”. The gamey, horsey edge on the wine in question was to him something related to the soils of Talbot. Of course, despite his experience, he was wrong; many years later I realised what we had tasted that evening was nothing more than Brettanomyces. But it was a good example of how many people viewed terroir. The idea that Mosel Riesling tastes slatey because of the slate on which it grows (and I often get a ‘sandy’ feel when tasting lesser St Emilion – but I don’t see many/any others reporting this) is another example of terroir misconstrued. Vine roots can’t absorb ‘molecules’ of sand or slate. Both sensations are quite plausibly the result of auto-suggestion, the idea that we are tasting the soil itself is vaguely nonsensical, and both provide plenty of ammunition for those arguing against the existence of terroir.

I think that terroir is an important determinant of how wine tastes is self-evident though. Taste two wines from one vigneron that he or she has managed the same way in vineyard and cellar; to appreciate the differences between the wines is to appreciate the impact of terroir. The wines of Lafleur don’t quite count, because although the grand vin comes from three terroirs, and the second wine from a fourth, the vinifications are different, introducing a second variable. You need a vigneron making several wines in exactly the same fashion to see the impact of terroir. It’s easiest in Burgundy, where one man or woman might have several wines from several vineyards, all harvested and vinified in the same manner, and yet they taste different. That’s terroir.

Richard Leroy, inspecting his terroir

Thinking back for comparable experiences from my own tasting history in Bordeaux or the Loire doesn’t produce a plethora of examples, but here are a couple, both from the Loire. A visit to Château de la Roulerie a couple of years ago brought several tastes from different barrels from different sections of the vineyard, the vines managed in the same manner, the vinifications the same, and yet the wines were profoundly different. The same was true when I tasted the component barrels with Richard Leroy (pictured above – inspecting his terroir, perhaps), before blending. Different sections of the same vineyard, same variety, same pruning, same vinification, same wood, but different wines. That’s terroir – it’s the difference between two wines, rather than intrinsic characteristics within each wine, that is down to terroir.

Reflecting on that conclusion, I have wondered whether there are any other plausible explanations for why wines from different vineyards, or even from different sections of the same vineyard, should taste so different. The only one that looked remotely promising was the impact of yeasts. Could different yeast populations in the two vineyards account for the differences?

There are those out there who think this possible, and indeed there are some who have wondered out loud why yeasts shouldn’t be included in the terroir ‘definition’. I have a problem with this though. Although there is no doubt that yeasts come into the winery on the fruit, and start fermentation, much of the fermentation process is completed by yeasts – specifically Saccharomyces cerevisiae – which are resident in the winery. [As an aside, there's plenty of research on this out there, and I recall Jamie Goode wrote a nice article on it for the World of Fine Wine a year ago. I also recall I wrote a lengthy letter in response, published two issues later (I was a bit slow in responding!) picking holes in the science.] Hence, because it is largely the winery yeasts that do the work, the two wines from the two different plots will largely be fermented by the same population of yeasts, removing this as a variable which could account for the ‘terroir‘ differences. Secondly, it seems likely that the population of yeasts within a vineyard will change over time. If yeast differences are responsible for terroir differences, why do some vineyards produce wines with identifiable characteristics year after year? Lastly, what about different sections of the same vineyard yielding different wines? Are we supposed to accept that the yeasts population is so diverse it differs from row to row?

So although yeasts can have a huge impact on flavour (this is an important consideration when purchasing cultured yeasts), when it comes to wines that are fermented spontaneously by indigenous yeasts, I doubt the yeasts play a very large part (or at least a very large consistent part) in the flavour differences we find between wines. Having said that, arguing for their role makes for good debate, so I hope research into how yeasts can affect flavour continues.

So terroir matters. It’s in the soil. But it’s not in the wine (or rather it’s not directly translated into an easily identifiable taste that makes for easy conclusions, like slatey Riesling or sandy St Emilion, although as I have alluded above some vineyards do behave in the same manner year after year). It’s in the differences between the wines that we can find it. When you look at it that way, it seems to me that the importance (or indeed, existence) of terroir is impossible to refute. Why else do wines made by the same people, in the same vintage, vinified in the same way, show such profound diversity?

8 Responses to “Terroir: A Matter of Difference”

  1. I watched an interview with Anthony Hamilton Russell by Wine Bandits from 2009 where he described the different soil types on his property and how the vines reacted to them. The interviewer at one point picked up a hunk of quartz and asked what impact that had on the taste of the wine. As something of a terroir sceptic, I was pleased with the response which was essentially that the terroir makes a difference, but that it wasn’t as simple as being able to taste the components, be they quartz, limestone, or gum trees growing nearby. I’m willing to accept that grapes from different terroir, even when treated the same in the winery, can produce very different wines, but I agree with you and AHR that the relationship between the terroir is both complex and not as yet well understood.

  2. I think yeasts should be considered part of the terroir, even though it is the “winery yeasts” (more of which may come in via insect rather than via fruit) and not in-row yeasts that complete the fermentation, and even though there are many strains of S. cerevisiae (and other yeasts) that are found early in the fermentation process and not later, i.e. the populations ebb and flow in a rather complex dance.

    This is because there are several new studies have found that there are region-speciifc populations of indigenous yeasts. The yeasts have adapted to their climate and possibly to a region’s wines.

    Example: this Sicilian study isolated 209 strains of S. cerevisiae from a few old wineries, found that ~15 of them were primarily responsible for completing fermentation, and moreover, were found to be superior to commercial yeasts w/r/t to both fermentation strength and wine quality. Here’s the study:

    http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0030428

    It may be that soil / site play a considerably larger role in terroir expression, but I think indigenous yeasts must be considered part of terroir, because they are about place.

  3. Thanks for these responses, drunkenadmin and Mike.

    Mike, I’m still not sure about including yeasts. But I guess if they are region-specific (and other region-specific elements, climate for instance, count) then they have some valid influence, but surely influence regional styles rather than the differences from one vineyard to the next.

  4. Mycorrhizal fungi, which are intimately associated with vine roots, have an important role in nutrient uptake for vines growing in soil of relatively low fertility. I would expect these, and the way in which they influence plant growth and composition, to be highly variable.

    On another point, I have never really understood what wine writers mean by terms such as ‘minerally’ or ‘stony’ that appear so frequently in tasting notes. How can a non-volatile solid taste of anything? Please could you give a precise explanation?

  5. Chris, it may be that yeasts are more specific than you give them credit for, as suggested by DNA analysis:

    Irene Stefanini, et al. Role of social wasps in Saccharomyces cerevisiae ecology and evolution PNAS 2012 109 (33) 13398-13403; doi:10.1073/pnas.1208362109

    Money quote: “Our results also reveal that yeast strains in wasps, grapes, and fermentation from the same vineyard, even in different months and years, are more similar than strains deriving from other environmental and geographic locations.”

    There are three constants in a vineyard from year to year: the soil, the grapevines (generally) and now the yeasts. Why shouldn’t they be part of terroir?

  6. Thanks for that comment Richard. The question on minerality is a very important one. It is a term increasingly used and yet one which never appeared in notes 10+ years ago (I think). I think it’s deserving of another post rather than trying to explain it. I also know Jamie Goode is busy writing an article on it for the World of Fine Wine, so if you’re a subscriber look out for that.

  7. Frank, thanks (I think! – the paper you cite isn’t an easy Sunday-morning read!) for the reference to the wasp paper. There has been a little buzz (groan…) about wasps and wine on Twitter recently, specifically their possible relevance to fermentations. I haven’t had time to click through to see what the ‘news’ was based on – looking at the publication date, perhaps this article.

    I’m not as convinced as you are by the paper; and like all published research the paper deserves appropriate critical appraisal. I’ve read as much as I can for the moment (but may come back to it again) but there are a couple of points I would like to raise.

    The research indicates strong genetic similarities between yeast isolates in Tuscan wine and Tuscan grapes, which is convincing, but I would like to see these species demonstrated as different to those found in other regions before the authors conclude there is “specific yeast “microbiota” in geographically and climatically different regions having a millenary culture of production of fermented food and drink” as they write on p13400.

    The research produces closely-related isolates of yeasts from different sites 20 km and 40 km apart, in one case on different species of wasps, which refutes the idea that yeast populations are highly localised – again p13400.

    Perhaps most significantly, I can’t find any results in the paper to support the use of “and years” in their conclusion that “[o]ur results also reveal that yeast strains in wasps, grapes, and fermentation from the same vineyard, even in different months and years, are more similar than strains deriving from other environmental and geographic locations”. Perhaps the research took place over several years with several sampling time points? The methods don’t declare this though, so I’m at a loss as to why the authors would make that conclusion.

    I’ve printed out the paper (much easier to read a pdf that way – especially with the detail in those diagrams) and may return to it next week when I’ve read it more thoroughly.

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