Earlier this year, I traveled from London to California for the Napa Valley Wine Writers’ Symposium. Looking through the list of panel speakers, I was surprised to see the British geologist Alex Maltman among the various, and overwhelmingly American, journalists, editors, and writers. I’d heard of him: the scientist who says rock-and-soil talk in wine tasting is a load of rubbish.
Maltman is an unlikely wine writer. Now in his early 80s, he spent most of his life in academia, researching and teaching about geology. He has also grown grapes and made wine at his home in the Welsh countryside for about 50 years, though his foray into wine writing is a more recent development.
To grind the man’s gears, you need only mention the word minerality, or draw a literal connection between a patch of gravel somewhere and the aromas in a wineglass. It was the emergence and growth of this kind of talk, around the early 2000s, that led Maltman to write about wine. His efforts to correct the record have been notable, most recently chronicled in Taste the Limestone, Smell the Slate, his second wine book. He has also contributed to both The World Atlas of Wine and The Oxford Companion to Wine and has had articles published in a range of wine publications.
Heading to California, I was expecting to meet a rather dry character. I knew Maltman had a reputation or, perhaps more accurately, reputations: to some wine people, he’s an educator, an enlightener, a trusted fact-checker; to others, he’s a spoilsport, a heretic, a crusher of limestone-related dreams.
We first met over dinner on the opening night of the symposium, and immediately my expectations were challenged. For a start, he introduced himself as Alex, despite his lofty title as the emeritus professor of geography and earth sciences at Aberystwyth University, in Wales. Furthermore, he’s very funny. During a field trip to examine the soil at Continuum Estate, at the top of Pritchard Hill, his talk included a dad joke about hummus and humus, complete with pause and a Cheshire cat’s grin for effect.
Geology is not everybody’s idea of a good time. When it comes to vineyard soils, I’ve found that most people fall into one of two camps: those (mostly consumers) who couldn’t care less; and those (introspective wine students and professionals) who feel they should probably know more. Maltman’s work has something to offer each. For those in the former camp: this is a guy who can make rocks interesting. And for those in the latter: don’t worry, it’s not all that scary.
I was delighted when Alex agreed to be interviewed for GuildSomm. He was generous with his time over Google Meet and email, and I am grateful to him for dealing with me with patience and good faith.
Charlie Geoghegan: How, when, and why did your academic work collide with wine?
Alex Maltman: Collide, that’s a good word, because the two pursuits came together abruptly after being quite separate for 30 years and more. I’d always done geology at university, undergrad and postgrad, then academic research and teaching. It was my profession. Wine was just a hobby.
Looking back, I always had an innate curiosity about things. Through cycling as a youngster, I got to wondering about road gradients and landscape, which led me to geology. As for wine, back then—I’m talking about the late 1940s, early ’50s—there was no wine in our household, and there weren’t any wine shops around. It sounds crazy now, but, if my parents did want to buy wine, then they’d have to go to a pharmacy. I can dimly remember peering in this chemist’s window, and, among the cosmetics and pharmaceuticals, seeing mysterious bottles. The labels and wording seemed exotic and fascinating, and I guess a seed was sown. Then, when I got to university and started drinking wine, that seed germinated.
I started buying books about wine. I still have most of them, and they show how much the wine world has changed. For one thing, they barely mention geology. But around the start of the new millennium, that suddenly changed. Wine writers started mentioning bedrock and what kind of soils the grapes were grown in. Now, it’s de rigueur to talk about vineyard geology.
CG: How did you get started with wine writing, then?
AM: You’ve got my wife to blame for that. When I grumbled about reading vineyard-geology things that were, shall we say, wide of the mark, she would say, “Well, what are you going to do about it?” Manifestly, a lot of those writers didn’t comprehend geology, which is understandable, as geology is very conceptual and doesn’t lend itself to a quick Google search. So I thought I should try and explain things simply, in the context of wine.
CG: You’ve said that until relatively recently, soil and geology weren’t part of the wine conversation. Why do you think that has changed?
AM: The wine world’s become much more competitive, and vineyard geology—the bedrock and soil—is just about the only thing that can’t be replicated by other wineries. It became a unique selling point, and journalists realized, Oh, that sounds good. And these days, with industrial foodstuffs and drinks, the idea that a product is not only from a specific place but from the soil, well, it hit the right buttons.
At the same time, this newly competitive wine world led to an upsurge in wine quality, partly because growers were striving for better fruit. They were paying more attention to their soils, matching rootstocks and methods, and there was an explosion of aerial soil mapping, soil-pit digging, et cetera, all of which fed into greater interest in geology.
CG: You’ve spoken about metaphor and how, for example, minerality can be either a very specific geological reference or something more figurative. Is there space for words like this to be purely metaphorical?
AM: We rely on metaphor for describing flavors, and it can have a scientific basis. If you strike two pieces of flint together, you might get some odor, to do with impurities in the flint giving sulfureous gases that also occur in certain wines. But most geological metaphors have to be mental inventions. Rocks and most geological minerals simply have no taste, so if we say a wine reminds us of a particular rock, we must be using our imagination in some way.
CG: How does being a scientist impact your appreciation of wine? Is there room for magic and joy in the unknown, or are these things mutually exclusive with science?
AM: As a rationalist, I don’t like the word magic, but exploring the unknown is the basis of science. Science is always learning new things, getting new evidence. There was the microbiology thing about 15 years ago. People never really thought about the soil microbiome before that. Quite what it means for finished wines is still unclear, but we now realize it’s important in the vineyard. There may be other new directions.
I’ve argued that these days the role of geology, certainly bedrock geology, is overexaggerated in wine tasting. But I’m always at pains to say science might be missing something. If somebody is thinking, Why isn’t he talking about that? please tell me. There’s always that open door. Science is never complete. What was the question again?
CG: How being a scientist impacts your own enjoyment of wine.
AM: The more we learn about how vines grow, how soils operate, and how wine evolves, the more dazzlingly complex and fascinating it is. I have always believed that understanding enhances appreciation. So, the more you understand about vineyards and how their wine comes about, the more wonderful it all is. I don’t think improved scientific knowledge is diminishing anything, as some have said about wine—it’s quite the opposite. It’s expanding appreciation.
CG: And is geology’s role in wine well enough understood from a scientific point of view?
AM: The basics are pretty well understood. What research has shown over and over is the importance of the water properties of the soil for overall wine character: how well drained the soils are, and to what extent the soil has some way of conserving enough water to see the fruit through the ripening season. The trouble is, a lot of different soils can do that. No particular geological soil has a monopoly on quality grapes. I keep saying geology is important in the vineyard, because, besides the water thing, the soil will dictate how the roots grow and, to some extent, the nutritional and thermal properties. But I don’t see how it can be so important for the taste of the finished wine.
CG: If the importance of vineyard geology is exaggerated, but nonetheless it is talked about a lot, seemingly by people who don’t necessarily understand it, where are we going wrong? Where is it coming from?
AM: The momentum is so enormous, with all the anecdotes, the marketing, the romance. Sometimes I think trying to convince people to rein the geological claims in a bit is like trying to keep the tide back.
Nevertheless, a lot of the taste assertions simply don’t hold up in truly blind tastings. In the few proper scientific tests that have been done, recognizing a soil from a wine just hasn’t worked. And even the looser, journalistic efforts have never been very conclusive. I don’t know how we change the thinking.
People do all these courses and qualifications and are breezily told about the importance of vineyard geology. It’s now the dogma. And these days, it’s a sommelier thing to throw around geological words.
CG: Do you think we just talk about this stuff a bit more than we should?
AM: I don’t really see, unless you’ve got a particular point to make, the reason for even mentioning the geology. For instance, I see in a tasting note that “the wine is made from grapes grown on granite soils.” Why have they bothered saying that? If it said, “Aged in new oak," or "Made from grapes grown on a sunny, south-facing slope,” it would be signaling something. But “grown on granite soils”—that doesn’t signal anything to me. When you look at wines around the world from granite soils, they’re hugely varied. Even in just a part of France: Cornas and much of the hill of Hermitage are on granite, but the wines are very different from those just up the road from the parts of Beaujolais also on granite. The fact that the soils are granite is interesting, but so what? And that’s never explained. You can repeat that example with slate, schist, sandstone, or whatever.
There can be indirect connections. Limestone is low in potassium, so the soils and the grape juice tend to be low in potassium, [which could bind] with the tartaric acid in wine to produce wine diamonds, crystals of potassium bitartrate. So, the tartaric acid is preserved intact, and maybe that’s the basis for the linearity and sharpness that’s often associated with limestone wines. But you’re not tasting the limestone in the wine!
CG: I’d love to know more about the role that your wine work played in your academic life once they did collide. Did it become a core part of your research and teaching interests? Or was it something on the side?
AM: Something on the side, definitely. My colleagues and the university system saw my wine interests as an amusing aside, light science at best. It was never an issue, though. My mainstream geology research was well established and internationally regarded, so I continued to feed that to the university, and everybody was happy. Then, when I decided at age 60 to take early retirement, I could pursue whatever I wanted, and the wine thing took off.
CG: When you made that move from academic writing to wine writing, what were the challenges?
AM: Well, the style of the writing. I was schooled in the precise but stilted style of academic scientific writing: verbs in the passive voice, for example, and no personal pronouns. It’s not about personality or pleasure—it’s all about exactness. You’ve got to make the sentence clear and unambiguous; it doesn’t matter if it’s hard to read! Nobody reads scientific papers for fun.
So, I looked at the way the wine writers I admired did it. The World Atlas of Wine is my favorite wine book, partly because I love maps, but the accompanying text is so concise and precise yet elegant and readable. How does Hugh Johnson do it? How does he construct his sentences? Andrew Jefford, too. And so, I learned from the masters. I looked there for inspiration.
CG: You’ve published several academic papers relating to wine. How much of your time, energy, and focus did wine come to take versus other aspects of geology?
AM: I published little on mainstream geology once I got going on wine. I was taken aback at the interest and support from the wine world. I realized that I had a contribution to make here, to help explain geological things to general wine enthusiasts. Those few academic papers on wine were largely to validate things for myself. I wanted to know that my wine writings would hold up to peer-reviewed scientific scrutiny.
CG: What areas of vineyard geology and wine are deserving of further academic research? Are there any burning questions you have?
AM: Ironically, very near my home is a long-established research institute, now part of Aberystwyth University, specializing in grasses, with environmentally controlled glasshouses, analytical labs, and the rest. If I were 20 years younger, I’d use their facilities and expertise to vinify grapes grown in pots, varying only the soil. It’s much easier said than done, but I’d like to see what data [would] emerge.
CG: As a voice in wine, what is your role? Are you a teacher? A police officer?
AM: A teacher. I try and explain things. I’m very careful not to preach, not to proselytize. I lay out the scientific understanding—you can take it or leave it. Some take it, and many don’t.
CG: What progress do you feel you have made with this teaching?
AM: Plenty of individuals have acknowledged my efforts, but it’s obvious from what we’ve already said that most wine folk are happy to sail on with baseless assertions as long as they sound good. For example, it’s become standard to casually say things like “The wine’s structure is due to the clayey soils,” without ever saying anything on how the soil does it. The host of other factors that we know do affect grapes and wines are sidelined; these days the soil’s the thing.
I’ve just written an article on volcanic wine, because that concept has become so very fashionable that I felt I ought to set out its geological difficulties. There are some incredibly interesting wines from volcanic areas with great backstories, but the proposition that wines produced anywhere in the world, no matter how, have commonality just because the rock from which the vineyard soil was derived came out of a volcano has to be justified. But that’s never done. The word volcanic brings compelling visions of incandescence and fire, but the products are made of the same geological ingredients as other materials. There’s nothing special. I guess a few readers of the article might rein in [the tendency of] describing these wines as fiery, pungent, and the rest, but I have no illusions that I will suddenly halt the tidal wave.
CG: When you visit vineyards and speak to winemakers, what sort of responses do you get to your work? How much do wine producers see eye to eye with you on matters of geology?
AM: Very varied, such is the diversity and richness of the wine world.
CG: Having carved a niche for yourself in the world of wine writing, is there anything more that you want to achieve?
AM: I hope people will start taking a more rational view of what’s actually happening in the vineyard. I’ve seen statements like “So far, scientists have been unable to find how it is that the taste of minerals gets into wine.” In other words, it’s the science that’s wrong. To me, beliefs have to fit with the evidence. Anecdotal belief is just that, no matter how widely and passionately repeated; it doesn’t carry the weight that empirical, testable evidence does. So, I’d hope people would adapt their thinking and maybe shed some of their out-there romantic ideas.
In a way, I’m carrying out a moral responsibility here. Having been funded for all those years from the public purse to do geology, I feel I’m now offering something back to the world of wine. Where it goes, we’ll see.