How much of what we perceive about the taste of wine is actually shaped by psychology? Are vineyard soils important contributors to a wine’s tasting profile? Why do so many wine producers highlight their soils as a unique factor that makes their wines stand out? Where do the “minerals” we taste in wine originate from?
In this episode of the Unreserved Wine Talk podcast, I’m chatting with Dr. Alex Maltman, author of the new book Taste the Limestone, Smell the Slate: A Geologist Wanders Through the World of Wine.
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Alex Maltman is Emeritus Professor of Earth Sciences at Aberystwyth University, in Wales, U.K. Alongside a decorated career in university teaching and research, Alex has for fifty years grown vines and made wine at his home in Wales. And through this, perhaps inevitably, he became interested in vineyard geology and its fashionable but poorly understood relationship with wine. This led to numerous publications in both the popular press and academic journals, and to various international lectures. Alex has contributed to a number of wine books, such as the Oxford Companion to Wine and the World Atlas of Wine, and is author of the acclaimed “Vineyards, Rocks, and Soils: A Wine Lover’s Guide to Geology” (Oxford University Press 2018). Published in April 2025 is a further book: “Taste the Limestone, Smell the Slate. A Geologist Wanders Through the World of Wine”. (Academie du Vin Library).
Natalie MacLean 00:00:01 How much of what we perceive about the taste of wine is actually shaped by psychology. Our vineyard soils important contributors to a wine’s tasting profile. Why do so many producers highlight their soils as a unique factor that makes their wines stand out? And where do the minerals we taste in wine originate from? In today’s episode, you’ll hear the stories and tips that answer those questions in part two of our chat with Doctor Alex Moltmann, author of the new book Taste the Limestone, Smell the slate. A geologist wanders through the world of wine. You don’t need to have listened to part one from last week first, but if you missed it, go back and have a listen after you finish this one. By the end of our conversation, you’ll also discover whether there is geological evidence to support volcanic soils, imparting certain characteristics to wine. Why vines can access nutrients from soil, but not from larger rock layers. Why rootstocks and fermentation yeasts should be considered when analyzing the taste profile of a wine. The aspects of geology and wine that Alex plans to write about in the future, and why Alex would like to share a bottle of wine with the comedy troupe from Monty Python movies.
Natalie MacLean 00:01:27 Do you have a thirst to learn about wine? Do you love stories about wonderfully obsessive people, hauntingly beautiful places, and amusingly awkward social situations? Well, that’s the blend here on the Unreserved Wine Talk podcast. I’m your host, Natalie MacLean, and each week I share with you unfiltered conversations with celebrities in the wine world, as well as confessions from my own tipsy journey as I write my third book on this subject. I’m so glad you’re here. Now pass me that bottle, please, and let’s get started.
Natalie MacLean 00:02:09 Welcome to episode 357 on city TV’s Breakfast Television. Recently, we chatted about how you should forget about pumpkin spice. I mean completely, Anyway, fall’s real MVP is in your wine glass. Ontario VQA wines don’t just taste great, they absolutely crush it this season. So when I hear people say sweater weather, I hear stellar weather. But that works too, because with more than 650 Ontario VQA wines hitting the Lcbo shelves, the biggest selection ever. There’s something for everyone’s taste and budget.
Natalie MacLean 00:02:44 Supporting local has never been easier or tasted this good one glass at a time. Of course. Mindfully in moderation. So we’re going to start with this Pinot noir from Canada’s southernmost winery, Pelee Island, one of the rare island vineyards in the world. In fact, they’ve just updated their labels to feature their gorgeous island. This Pinot has a lovely, silky texture with flavours of ripe cherry, earthy mushroom and a whisper of spice. I’d pair this with Island Harvest Stew, slow simmered with root vegetables, crispy duck breast with orange glaze, seared salmon with a wild rice pilaf, roasted beet salad topped with a tangy Chev, or a maple glazed pork tenderloin that caramelize in the oven. I also have their Pinot Grigio that’s crisp and refreshing. It’s like a breath of fresh lake air with bright citrus and green apple notes dancing on a mineral backbone. It’s crisp, clean and refreshing, with hints of white peach and a zippy finish. So now we’re going to play a little trivia game as we sample. So true or false? The oldest winery in Canada is 75 years old.
Natalie MacLean 00:03:56 Okay. That’s disturbing. I don’t think I’ll use that buzzer again. It’s false. The oldest winery in Canada is actually 150 years old. And it’s the one I just spoke about. Pelee Island, where wine has been made since the 1860s. Winemaking in Ontario has a long, rich history. Next up, the Inniskilling Cabernet Franc. One of the cool climate grapes that is a star in Ontario. This full bodied red shows dark plum and raspberry notes with a velvet backbone. I’d pair this with amber grilled lamb chops scented with rosemary chard peppers stuffed with herb couscous. Mushroom risotto stirred to creamy perfection. Beef bourguignon bubbling with red wine and thyme and baked eggplant parm layered with molten mozzarella. I also have their late Harvest Riesling, which tastes like fall peaches in a glass. This is off dry with juicy peach, ripe pear and a zesty lime finish. I matched this with caramelized onion tart and puff pastry. Maybe a Thai green curry with coconut and lemongrass. Butter chicken simmered to velvety richness. Apple strudel dusted with cinnamon sugar or spicy jerk shrimp straight off the grill.
Natalie MacLean 00:05:14 Hungry yet? All right. Trivia time. True or false? In 2005, for the first time ever, a Canadian wine won the Grand Prix Donner in Bordeaux, France, the highest international award that judges hundreds of wines, if not thousands, from around the world. All right, that’s false. And I will save your nerves with this buzzer. It was actually back in 1991, 34 years ago, that Enniskillen Vital Ice Wine won this prestigious award, establishing the world class potential of both this winery and Canadian wines more broadly, all of whom have gone on to win thousands of international awards for their quality. Next up, we have this opulent Chardonnay from Chateau de Charme, with its creamy texture and aromas of baked apple, lemon zest and a hint of oak spice. I pair this with a Caesar salad topped with crisp prosciutto, roasted chicken glazed with lemon in time, or a lobster mac and cheese bubbling from the oven. Wild mushroom quiche with a flaky pastry or scalloped potatoes layered with cream and nutmeg.
Natalie MacLean 00:06:20 I also have the Chateau Ducharme Gamay Noir, a smooth, medium bodied red that has notes of juicy cherries, red berries and a smooth finish. It’s like the golden retriever of red wines friendly, approachable and impossible not to love. I pair this with a duck Magritte with roasted figs in red wine, or maybe a thin crust margherita pizza bubbling with mozzarella, grilled sausages on a smoky barbecue, cranberry glazed turkey sliders, or even a lentil stew rich with spices. Your trivia question. Does VK stand for Vintners Quality Alliance and not Vineyard Quality Assurance? Very tricky. That’s true.
Natalie MacLean 00:07:05 Oh, yes.
Natalie MacLean 00:07:07 Okay. That goes on too long as well. The VQA symbol stands for Vintners Quality Alliance, which you can see on the labels of all the wines that I’m talking about today. And it means they’re made from 100% Ontario grown grapes, meeting strict quality standards to give you confidence in the wine’s quality and local roots. It’s the blue checkmark of Ontario Wine verified. Delicious. All right. Next we have Palatine Hills.
Natalie MacLean 00:07:33 Oh goody. Rosé. Isn’t that a fun name? It’s bursting with strawberries, cherries and has a crisp citrus lift. I’d pair this with strawberry and goat cheese crostini. Or maybe spicy tuna sushi roll with wasabi. Watermelon feta salad would be of divine with mint grilled shrimp skewers brushed with garlic butter. Those grilled shrimp skewers keep making it into my dreams at night and prosciutto wrapped melon slices. I also have the Palatine Hills Ramblers schmooze or Cabernet Merlot. Got brilliant marketers down there with their naming conventions. It’s from Niagara Lakeshore and a platinum medal winner with notes of blackberries, plums and baking spice. And I pair that with sticky barbecue ribs layered in sauce or a flame grilled burger with smoked cheddar. How about campfire nachos dripping with chipotle cream? Braised short ribs falling off the bone? Or maybe a wood fired pizza with caramelized onions and gorgonzola? All right. Trivia question. Ontario has more than 180 VQA wineries. So true or false? The majority are family owned. Well, now that is true. The majority of Ontario’s VQA wineries are family owned.
Natalie MacLean 00:08:52 Palatine Hills is a great example started by John Neufeld and now his two sons, John Junior and Charles, carry on his tradition. And finally we have the Henry of Pelham family, Lost Boys, Baco Noir from vines that the speck brothers Dan, Paul and Matt planted his teenagers in the summer of 1984. Thus Lost Boys, as they spent their summers grumbling about how they had lost their summers working on the farm. But now, of course, they’re all grown up, unlike Peter Pan, and they are reaping the fruits of their labors. It’s dark and smoky, with blackberries, cloves, and a savory finish, and I’d pair it with smoked beef brisket, slow cooked until tender, roasted vegetables glazed in balsamic garlic parmesan frites, hot and crisp for maybe a shepherd’s pie with buttery mashed potatoes, or maybe portobello mushrooms stuffed with herbs and breadcrumbs. I also have the Henry of Pelham family tree, the glass eye. Pinot Grigio is a crisp, refreshing white with citrus, green apple and mineral notes. I’d love this with ceviche.
Natalie MacLean 00:09:54 Kissed with lime, chicken curry with ginger and turmeric. Samosa with chickpeas or maybe a tamarind chutney. Pear, walnut and goat cheese salad drizzled with honey or even steamed mussels in a white wine broth. Ontario Wine Country stretches from Pelee Island up to Prince Edward County, and wines from all of these regions have such different styles and can be found in the Lcbo. So true or false? Ontario Wine Country is roughly on the same latitude as Tuscany, Italy. That’s true. Southern Ontario shares a similar latitude with Tuscany, Bordeaux and Rioja, Spain. Ontario is not only on the same latitude as the world’s most renowned wine regions, but it’s also, I believe, on the same level, quality wise. And the amazing thing is that you do not have to travel thousands of miles to find these wines. They’re all at your closest Lcbo, and I encourage you to ask the staff about them, as they’re very knowledgeable and they have a real passion for supporting Ontario, just as we do now, since it’s never been more important to support local.
Natalie MacLean 00:10:59 So cheers to that. And on Instagram, you can find me reviewing these wines and others from around the world at Natalie MacLean Wine. So follow me there. I’ll follow you back and online. My website is Natalie MacLean dot com. So here’s to the Vineyard Dreamers, the Harvest Achievers, and all of us here, the local believers. Cheers. I’ll also link to all of these wines in the show notes at Natalie MacLean. 357. In other news, I can’t believe I get to represent Canada as a 2026 finalist for the International Wine and Spirits SC Wine Communicator Trophy. I am deliriously happy to be shortlisted among some incredible talents, including Emily Stenborg from Hong Kong, Helen McGuinn from the United Kingdom, Marisol de la Fuente from Argentina, and Helena Nicklin from the United Kingdom. The IWC Communicator Trophy is a globally recognized award, quoting here from their website that honors individuals whose communication has made a remarkable contribution to the understanding of wine. And I appreciate the judges comments in the nomination. I’ll quote them.
Natalie MacLean 00:12:19 Natalie McLean’s Unreserved Wine Talk podcast, yay! Was recognized by The New York Times and Apple as one of the best drinks podcasts. She’s published three bestselling books, writes for international media, and appears regularly on Canadian television. Her website attracts millions of visitors annually, while her apps and newsletter engage large consumer and trade audiences. She was named Canadian wine industry champion, reflecting her role in promoting Canadian wine at home and abroad. So a huge thank you to you for listening to Unreserved Wine talk. This nomination is for you. The winner will be announced November 12th in London, England. So let me know what’s your favorite way to learn about wine, books, podcasts? Avi videos? Tasting something else? Let me know. Back to today’s episode. Two of you are going to win a copy of Doctor Alex Altman’s new book. Taste the limestone. Smell the slate. A geologist wanders through the world of wine. If you’d like to win a copy, please email me and let me know you’d like to win.
Natalie MacLean 00:13:24 It doesn’t matter where you live. I also still have two copies of The Wines of Brazil to give away, and I’ll choose four winners randomly from those who contact me at Natalie at Natalie MacLean dot com. Keep them for yourself or give them as gifts. Okay, on with the show. Now there’s been a craze for volcanic soil wines. Is that just marketing? What is that? You did a blind tasting with volcanic wines. Tell us about that.
Alex Maltman 00:13:56 Oh that blind. That was in Hungary. They’re very keen on on volcanic wines in Hungary because they got a lot of volcanic rocks and it’s like, whoa, this is a trendy thing. And Hungary, winemakers, bless them, are trying to get their wines on the world map. And it’s a battle. A Hungarian wine writer was telling me this the other day, it’s dire situation, the competition. So they got to latch on to whatever they can to try and sell their wines. And because volcanic wines had suddenly become fashionable, they latched onto that.
Alex Maltman 00:14:27 And I went to this conference with a blind taste. Well, the good long story short, it didn’t work. It was all over the place.
Natalie MacLean 00:14:33 They couldn’t tell.
Alex Maltman 00:14:35 Oh, I couldn’t tell. And it’s the same goes for limestone and granite and everything else. Now, if you can recognize the wine and you know what soil that wine comes from, then you may be able to get the tasting. Not long ago, a whole battery of half a dozen different soil types. Can you guess the soil types? And is a blind. And the only one that got remotely close was limestone. And quite a few people say, I think this is from limestone. And yeah, it was just about right, but it was Chablais, possibly the most distinctive wine of all.
Natalie MacLean 00:15:10 And. Okay. Chardonnay. Cool. Crisp.
Alex Maltman 00:15:13 Yeah. This is Chablis, and I know Chablis grown on limestone, high marly rocks. I think they were guessing because they were guessing it was Chablis rather than the limestone. The rest of the wines was all over the place, and every wine tasting I’ve been to or read about this has been the case.
Alex Maltman 00:15:31 These things never hold up in in truly blind tastings, there’s not much an incentive for scientists to test this. And so there’s not a lot of scientific literature on it. But there was a test in, the Netherlands, which I recount in the book in the limestone chapter, I think. These geologists had several Dutch growers planned for different cultivars, each in different soils, and then try to grow the grapes, vilify the grapes uniformly. Then they sent the finished wines off to a completely independent expert tasting panel. Actually, it was in Germany, guys, and they knew nothing about the test. We’ve just got all these glasses of wine. Can you put them in any groups? Is there any commonality between any of these anonymous wines? And they could to some extent, but it was the cultivars. They didn’t know what the cultivars were about.
Natalie MacLean 00:16:36 Cultivar, meaning the vine type or the clone of the grape.
Alex Maltman 00:16:39 The vine type, the vine type.
Natalie MacLean 00:16:40 Okay.
Alex Maltman 00:16:41 Yeah. What you’d call a varietal in a in the wine.
Alex Maltman 00:16:43 Pinot noir. Chardonnay. Cabernet sauvignon. They’re properly called cultivars. Yeah. Variety, if you like. They recognized the varieties or not. Didn’t recognize the varieties. They found a commonality between some of the wines is because they were from the same variety. Nothing came from the soils. They then repeated the experiment, and this time they used 3 or 4 different yeasts. Again, can you recognize any commonality? And again, they could they were able to put the wines from a certain yeast in a group. Didn’t know what he was, what the yeast was. But yeah, these wines have something in common. These wines have something in common, different yeast. And these wines have something in common. These are not something different. Cultivar variety soils. Didn’t get a look in. The soils didn’t come through at The soils Songs apparently were irrelevant, and that is in line with all the blind tasting tests I’ve read about or be involved in. The claims just don’t hold up. But the thing about volcanic wines is, I mean, it’s pretty obvious.
Alex Maltman 00:17:51 Volcanic eruptions spectacular. So absolutely. And that touch of danger, of course. And I mean, they are. It’s one of the great sites of the geological world, without question a volcanic eruption. And everybody knows that. Everybody’s seen pictures of, you know, volcanic mines. Well, but I have a big problem with the concept, the products of a volcanic eruption, no matter how spectacular, when it all settles down and turns into rock, are just the same as any other rock. It’s the same geological minerals. They are made of quartz and feldspar and mica, just like other rocks. There’s nothing special. There’s nothing magical just because it came out of a volcano. And so why should it give anything special to wines? Again, nobody’s ever explained how it works. And I think what gives the game away to me in my cynical mode is if I read tasting notes of a so-called volcanic wine. And volcanic soils are so incredibly varied. How can there be a commonality? Anyway, you can bet if that person writing the tasting notes knows it’s from volcanic, so you will see words like piquancy, pungency, fire, Innis, brimstone.
Alex Maltman 00:19:15 Incandescence. Yeah, yeah. Smoke. Smoke is a good one.
Natalie MacLean 00:19:18 Smoky?
Alex Maltman 00:19:18 Yes. Well, you know, some volcanoes look as if they are smoking, but that’s ash. That’s ash. Fine. Ash coming out of the volcano. If there is any sort of gases, it’s obnoxious. Sulfur gases. Sulfur dioxide. Hydrogen sulfide. Yeah. It’s not wood smoke. It’s not barbecue smoke, you know. So this one is smoky from the volcanic soils. No no no no no. And as I’ve indicated, if the person doesn’t know it’s from volcanic soils, then you’re lost. If they do know, then. Yeah. Pungency fineness comes into the notes. And I just read last week from a very respected UK wine merchant, the May list. it said wines from volcanic soils have a certain piquancy, and I’m sure 99% of readers will just go by. Oh, yeah. Yeah. Right. Okay, good. But to me. Oh. Oh, yes. Is that so? Why? Never said.
Alex Maltman 00:20:15 How does it work? And would you be saying that if you didn’t know the wine room for volcanic soils? Yeah. When I get in this mode, this phrase flits across my mind. Wishful thinking. And this whole thing about volcanic wines and a lot of other things. Yeah, it’s wishful thinking. Would it work? And I wish it were, but I just I have to go with the evidence and I can’t see how it can be.
Natalie MacLean 00:20:41 Well, I think what does have a certain piquancy is volcanic wine marketing. So that definitely has some piquancy and some fiery tips to it.
Alex Maltman 00:20:49 Anyway, they’ve got to sell the wines at the end of the day and it is such a competitive business, you’ve got to latch onto what you can. And incidentally, I’ll throw in at this point, growing vines and making wines is pretty easy to replicate anywhere, given the decent climate, but not the soil. That’s just about the only factor that is very difficult to reproduce somewhere else. And so whatever grower finds he’s got a certain soil, he’s going to say our soil is special.
Alex Maltman 00:21:24 That’s why our wines are so special, because we’ve got this unique style, because he knows it probably is nowhere else. Not in detail anyway. Another chapter in the book is about the Australian pioneer called James Busby. And although I think he got quite a lot of things, well, at least questionable, one of the things he did get right in his great 1825 manual was the fact that it occurred to him in travelling in France, that the soil type was about the only thing that can’t be replicated by other growers. And so producers latch onto that, and the specialness of their soils is right there and is right now. You know, you can’t blame, in this competitive world, a producer saying our soils are special because other people aren’t going to say, oh, we got the same soils because he can probably make a case, but in detail they’re a little bit different. It’s a great selling point.
Natalie MacLean 00:22:24 It is. Now just before we leave this and dive into those four elephants that have been waiting patiently for us in the other room.
Natalie MacLean 00:22:30 Larger layers of rock, of course, aren’t contributing anything to vine roots, as they cannot access them or process their inorganic materials or nutrients. However, help me understand this last bit. Isn’t soil partly disintegrated rock or geology? And therefore does it contribute some nutrients in that soil that’s been fractured or disintegrated? Or is it all the vine nutrients are coming from only the organic matter?
Alex Maltman 00:22:57 Okay. Well, this does link in with the first elephant as it happened, the organic matter. Yes. Soil is disintegrated rock. It may have formed by fragmentation in place, the local bedrock underneath, or it may have been brought in by wind or rivers or ice from far away. But it’s still disintegrated rock. This is true, but the little fragments that make the soil framework are still little chunks of rock are the geological minerals that make the rock. So you’ve still got the same problem. The potential vine nutrients are still locked in those little fragments. And so what’s going to happen in this fragmented material? The soil is that a whole battery of chemical and physical operations have got to get to work.
Alex Maltman 00:23:51 And we sum those up in the word weathering. And through time, weathering may enable some of those constituent elements to be at the surface of the geological mineral and may make it accessible to the soil. Water may dissolve in the soil water, and then it can be accessed by the vine roots if the vine roots so choose. Technically speaking, it’s a process you may have heard of called cation exchange.. We talk about the cation exchange capacity of different minerals. Clays are the most important one, and they can have a lot of loosely held potential nutrients cations at their surfaces. And they may detach, get in the soil water. And so they become potential VI nutrients. And if the selectivity mechanisms of the route say, yes, we need you to metabolize, we’ll take you in then. Yeah, it’s a vine nutrient. And they originate usually in a geological mineral. And so I call them mineral nutrients because they derived ultimately from the geology. There is however, on the side one important nutrient which you don’t normally call the mineral nutrient because it’s not in rocks nitrogen.
Natalie MacLean 00:25:16 Are it’s in the air, right?
Alex Maltman 00:25:19 Yes, it is in the air. You’re dead right. 70 odd percent of air is nitrogen, but plants can’t access it. The only way plants can get the vital nitrogen is through bacteria in the soil that can capture the nitrogen, and then through microbiological processes, can get it into the vine roots. And so here’s where the organic fraction of the soil becomes important. The so-called humus h u m U.S. humus.
Natalie MacLean 00:25:53 Humus with a long u. Yes. Let’s not get it mixed up.
Alex Maltman 00:25:56 Yeah. Nothing to do with hummus. Hummus is nicer for humans to eat than humus, but for a plant, it’s gotta be humus. Partly because that’s where the nitrogen comes from. And in practice, to a large extent, phosphorus and sulfur. Because there’s not a lot of those things in most rocks and minerals important in that respect. But here’s the important thing that I argue in the first of those elephants in the room thing. These weathering processes that I’ve just outlined are slow.
Alex Maltman 00:26:30 They’re very, very slow. I mean, if you think of an epitaph on a gravestone after centuries, the epitaph might be becoming indistinct. Eventually will disappear because of weathering centuries. Now, if a farmer wants to abstract a crop every year, the soils got to provide a new suite of nutrients each year. And weathering is far too slow to be able to do that. So what happens in nature is not agriculture, but say in a forest or something like that. The nutrients are recycled in the fall foliage and things fall off. Settle there. They’re decomposed and they’re reconstituted. And the nutrients that the previous year’s growth are now available for use again and humus as a far higher cation exchange capacity than any geological mineral. So there they are, being replenished year on year and available. And that’s why forests happily grow year on year. In an agricultural situation. The farmer is extracting a crop every season, so if he just keeps doing that without putting anything back, then everybody knows the soil will become depleted and before long you won’t get much in the way of crops.
Alex Maltman 00:27:52 And as I say in this section, I begin it by quoting Woody Guthrie and the dust storms of the American prairies in the 1930s. That’s because the over cropping the the farmers weren’t putting goodness back in the soil. Now they have to. Vines don’t need much in the way of nutrients. They have very modest needs, which is why vines can grow on very barren looking soil. But the organic matter has to be there to some extent. And so the farmer will let foliage and his grape stems rot down in place. He may let weeds or cover crops decay in place, or he may spread a bit of pumice in the vineyard. So the vine gets through the organic matter, the vines it needs year on year. Now, the corollary of all this, as I see it coming at it the other way around, for the purposes of this elephant in the room, when some wine commentators are saying, yes, I’m getting these minerals from the soil, I’m getting graphite, I’m getting flint, I’m getting talc and stuff from that, because it’s been taken up by the vine root and transmitted through to the vine.
Alex Maltman 00:29:04 Well, no, that doesn’t happen like that. But in any case, any nutrients that were taken up by the vine root and did make it all the way through to the finished vine, almost certainly in practice, will have originated in the humus for the reasons I said.
Natalie MacLean 00:29:21 But we don’t like to talk about rotting leaves and dead bugs.
Alex Maltman 00:29:24 And also we don’t know.
Natalie MacLean 00:29:26 That doesn’t make for a nice tasting note.
Alex Maltman 00:29:29 And I’m not advocating that we should. Rather, I’m advocating let’s rein in this geology thing that I’m tasting flint and so on, because Flint’s inert. It can’t get in the wine. If it did, it’s insoluble. You’d see little specks in the wine. Well you don’t obviously. So no, no, let’s rain in on that. I’m not saying we should start talking about humus, but I think it points up the need to be a little bit more careful, a little bit more precise about when you start talking about things taken up from the soil. So that’s the first elephant in the room.
Alex Maltman 00:30:03 Humus.
Natalie MacLean 00:30:04 Number two elephant rootstock. The as you say, the engine room of the vine, especially those that were resistant to phylloxera. And that was the root loss that devastated European and California vineyards in the 1800s. Most vines today are grafted onto. These rootstocks. So the vine is spliced, as I understand it, and attached to the base rootstock. So they grow together as a new plant. But you’ve said evidence shows that Shiraz vines grafted onto what they call 110 Richter rootstock compared to those grown on their own roots. There are differences in taste and intensity, in colour and so on. Those rootstocks do have a real impact that this second elephant.
Alex Maltman 00:30:42 Well, at the time of the phylloxera crisis. And what are we going to do? Our livelihoods and why are being destroyed and wines disappearing before our very eyes? Had to find some solution. And one faction argued for grafting onto North American rootstocks as the answer. It’s a bit of a battle. Other factions wanted chemical solutions, putting all sorts of nasty stuff in the vineyard, and there was a hybrid faction as well.
Alex Maltman 00:31:10 But, you know, the grafting solution won out. And one of the reasons was they promoted that solution. So it doesn’t affect the wine flavor. The wine flavor is still coming from the British vinifera, the French vines.
Natalie MacLean 00:31:25 The vine on top that’s grafted to the base.
Alex Maltman 00:31:27 That’s still Chardonnay and stuff, and that’s what’s making the rootstocks. They can combat phylloxera, but it doesn’t affect the taste. That’s how the grafting solution was promoted and came to be. And now, in much of the world, as you said, is now standard. And the rootstocks bear the names of these pioneers whose name most wine enthusiasts don’t know. Like, say, Franz Richter that you just mentioned. Well, they really should be known, because if they hadn’t come up with this solution, well, we wouldn’t have wine in the way we know it today. Well, okay, there are a few areas Chile, South Australia that still are.
Natalie MacLean 00:32:03 Resistant naturally.
Alex Maltman 00:32:05 To blocks, for instance. But the point is, over the years, scientific research has shown that the rootstocks can affect the vine flavor.
Alex Maltman 00:32:15 Not in a bad way. It just brings out certain characteristics rather than a characteristics. And I quote some examples in the book. And you mentioned one about Shiraz and Richter. Yeah, they got different end product with the Richter rootstocks over on rootstocks and the whole batteries of these things. So yeah, the rootstocks apparently do affect the flavor to some extent. So my point is here. Shouldn’t we be looking at the rootstocks of part of the tasting profile of a wine and tell us what the varietal was, and maybe something about the climate or whatever, and the winemaker. But rootstocks are never mentioned. But yet it seems they are contributing to the flavor. So I just came out with this elephant in the room. Frey. So so that’s the second elephant in the room?
Natalie MacLean 00:33:06 Absolutely.
Natalie MacLean 00:33:07 So our tasting note so far is, dead leaves, rotting bugs, and 110 richer Extra rootstock like that. Well, go buy a case of it.
Alex Maltman 00:33:16 Hey, is this food for thought, is I?
Natalie MacLean 00:33:18 Yes.
Natalie MacLean 00:33:18 Absolutely. No. It’s great for organizing and I love it because it’s challenging. Received wisdom of which there is too much in the wine industry. And if it makes you think, I think that’s wonderful. So let’s get on to the third elephant.
Alex Maltman 00:33:31 What I’m trying to do, I’m not to preach or sell anything.
Natalie MacLean 00:33:35 Absolutely.
Alex Maltman 00:33:36 I’m just not laying the situation as I see it. Make of it what you will. Yep. The third one is very parallel to the rootstock argument yeast. When a winemaker is going to ferment his juice, he’s got to make a decision about what yeast is going to imply. And they manifestly different strains affect the fermentation, affect the outcome. And you never see yeast mentioned. The only time we see yeast mentioned is if a winemaker has decided to use so-called wild Old yeast, you might say this wine juice from wild yeast, but that’s a bit of a get out. Really? Because it’s not just one wild yeast. There’s a whole battery of different species in different genera of wild yeasts, each of which gives different things.
Alex Maltman 00:34:28 So I’m just saying wild yeast doesn’t really take as much further forward, but most winemakers prefer the control you get by bringing in a commercial cultivated yeast. Well, you just glance at a supplier’s catalogue straight away, hits you in the face. Our yeast can bring out floral notes, can bring out fruity notes, can do this, do that. Our yeast strain technical names again will make your wine this make our wine that. So by the same argument as with the rootstocks, if the yeast is not important in making your wine taste like it does. And the winemaker will select a yeast to try and get a wine that he’s aiming for. Well, shouldn’t we, as tasters come along and say, well, what kind of yeast was involved? Shouldn’t we acknowledge part of this fruitiness, part of this dryness or whatever is due to the yeast? But as I say, apart from this mention of wild yeast, perhaps yeast is not mentioned. It’s an elephant in the room.
Natalie MacLean 00:35:30 And as you say, yeast.
Natalie MacLean 00:35:32 Of course we know for fermentation, yeast eats the sugars and releases the majority of the compounds that give wine its flavours. So are the flavour precursors compared to grape juice, its yeast is kind of the difference between grape juice and wine. But again, back to that tasting note. We’re getting into, you know, rootstock 110 and yeast strain whatever two six be whatever. I mean but it really does have a profound influence for our tasting notes are deteriorating. Meanwhile.
Alex Maltman 00:36:02 I think what I’m saying is is calling for tasting notes to be more precise, more careful, not make Cavalier remarks, particularly about the vineyard soils. But think about it.
Natalie MacLean 00:36:12 Absolutely, absolutely. Okay. I think the biggest elephant sometimes maybe, perhaps is consumer psychology or so many, so many factors when it comes to you’ve grouped them under psychology, but the wine costs the color, the origin, rarity, age, critic ratings, tasting ambience, our eating habits, medications we’re on, our age, our genes, and so on all can influence the taste of wine as much as I would argue rootstock and yeast and everything else.
Natalie MacLean 00:36:42 You mentioned a really interesting study about the weight of a bottle and price.
Alex Maltman 00:36:48 Yeah, I just put that in for a bit of life, really. As you say, there’s a whole array of these different variables and interesting bits of academic research showing how this particular thing influences our taste. Perception is a good one about music, the music that’s playing in the background, but it’s in the book and all sorts of other things too. I just brought out that glass thing. There was a little study. There was a very interesting cognitive psychologist at the University of Oxford, Charles Spence. He’s done a lot of stuff like this. He did this study with glass. He and a student, I guess, bought a whole pile of wines from the local supermarket in Oxford, I guess priced between about five English pounds. It doesn’t matter. Dollar trillion dollars would do up to about 35 English pounds. So that’s a big, good range of what many people would spend on wine. And they weighed the empty bottles and they plotted this graph of weight of the bottles against price of the wine.
Alex Maltman 00:37:55 And it was almost a straight line relationship between the weight going up with price. And it came down to it was a bit larger. It’s a bit of fun, really, but nevertheless, there’s something meaningful behind it. For every pound more you spent. The bottle was eight grams heavier.
Natalie MacLean 00:38:14 So you’re buying more glass weight.
Alex Maltman 00:38:16 So you pay more money, you get more glass. Of course, that was I think 2013, that study. And it’s a very neat correlation neat study there. Of course, it’s all been put in turmoil a little bit now by the need for sustainability and the move to lighter glasses. I guess it might not work quite so neatly now, but it’s not the glass thing. That’s the point. It’s the psychology that people think, oh, heavy bottle, this must be a class wine and all these other things that affect our perceptions of taste. There are lots of them. Some of them I mentioned in the book. But I think the bottom line, which I again, it’s food for thought really, but I finish up that section in the book.
Alex Maltman 00:39:04 It makes you wonder how there’s any consistency between one dates. There are so, so many things there. Well, how is it we’re getting all this? And I think in a word, the answer is placebo. The placebo, the suggestive power of the placebo effect. And I think except the very confident tasters perhaps like yourself, Natalie, and maybe a lot of people listening to this, I don’t know. But for many wine drinkers, a little bit lacking in confidence about wine. If some wine expert says, well, you’ll be getting these notes and you’ll be getting a bit of this and a bit of that and a bit of the other. Oh, really? Yeah, that’s what I’m getting. It overrides all these more academic things about music. Weight of the glass, shape of the glass and the other flowers in the room and what colours are and all that, all that gets subsidiary to the placebo power. Rather like a clinician saying, take these tablets, you’ll be better. If the Wine Authority says you’re going to taste vanilla.
Alex Maltman 00:40:13 Yeah, I’m getting vanilla. And I think that’s the bottom line really. But anyway, food for thought.
Natalie MacLean 00:40:19 I love it, I love it. Now, have you discovered anything since that you might add to a new edition of this book? And or are you thinking of writing another one? I don’t want to exhaust you here. You’ve just.
Natalie MacLean 00:40:29 Finished this book, but.
Natalie MacLean 00:40:30 Is there anything new that’s popped up in your mind, a new curiosity or anything like that?
Alex Maltman 00:40:36 Yeah, there are always new topics to write about, and I’ve got plenty of ideas for new topics. And I have a new world of Mine wine article in the pipeline, which isn’t in the book. It’s about South Africa, about the Cape. Same style, stories and anecdotes about the Cape and so on. And I’ve got ideas for future things. And so, yeah, I’m always thinking about nothing. But I know there won’t be a second edition of this book. This is the present anthology, but we’ll see where things go in the future.
Alex Maltman 00:41:09 I’ll write more articles.
Natalie MacLean 00:41:11 Oh that’s wonderful. If you could share a bottle of wine with any person outside the wine world, living or dead, who would that be? Alex.
Alex Maltman 00:41:21 Oh, kill her a question. Ha! Monty python.
Natalie MacLean 00:41:25 Oh, really? Have a good laugh.
Alex Maltman 00:41:28 Absolutely.
Natalie MacLean 00:41:29 Yeah.
Alex Maltman 00:41:30 There is a monty Python sketch, and it’s actually delivered by Eric Idle. But what it’s worth.
Natalie MacLean 00:41:36 Is it about.
Natalie MacLean 00:41:36 Wine at.
Natalie MacLean 00:41:37 All?
Alex Maltman 00:41:37 Yes it is.
Natalie MacLean 00:41:38 What’s the gist of it? Is it a blind.
Natalie MacLean 00:41:40 Tasting.
Natalie MacLean 00:41:40 Or.
Alex Maltman 00:41:40 Something funny? No, no, no. It’s Eric Idle in front of the camera, pretending to be a wine expert. Oh, and he said, let’s share a bottle of this Perth pink. I think he says it’s known for its astonishing afterburn. I think he’s what he says. Oh, we could have a bottle of Chateau something or other. This really is a wine for laying down and forgetting about.
Natalie MacLean 00:42:09 Oh no.
Alex Maltman 00:42:10 No no. Here’s a wonderful wine.
Alex Maltman 00:42:12 This is. What is it now the tennis player. Rod Laver. Cock the Rod Laver. oh. You said eight bottles of this and you’ll know you’ve enjoyed it. He bottles it. So it’s just a little face to camera sketch.
Natalie MacLean 00:42:30 Yeah. Classic. This has been absolutely wonderful. Alex, is there anything we haven’t covered that you wanted to mention as we wrap up?
Alex Maltman 00:42:41 I would just emphasize that I’m just trying to throw out food for thought. I’m in an unusual position of knowing about these several different strands. So as I see it, this is how vines and soil interact. So here’s the evidence as I see it. Make of it what you will. I’m not trying to convert people or sell anything or preacher I know. I’m not a campaigner. I’m a teacher. I’m trying to explain things and what people make of it. Having thought about it with an open mind. It’s your business, dear listener.
Natalie MacLean 00:43:21 Absolutely, absolutely. You’re a thinker and a teacher and a writer and a wanderer.
Natalie MacLean 00:43:26 And I hope you keep that going. So, Alex, where can we find you online? You and your books. Are you to have a website or social media?
Alex Maltman 00:43:34 No. People of my age. You know, I don’t do the social media thing too much. I do emails.
Natalie MacLean 00:43:42 I know we can get your book from Academie Davina, which we’ll put in the show notes, as well as probably Amazon and other places.
Alex Maltman 00:43:48 Oh, yes. There any. Yeah. So around the world I see being listed. Yeah, yeah, yeah. It’s easy to get hold of.
Natalie MacLean 00:43:54 All the bookstores.
Alex Maltman 00:43:54 Yeah. I’m more than happy to converse via email with interested correspondence. Genuine? Yeah. More than happy.
Natalie MacLean 00:44:05 Interested polite correspondence.
Alex Maltman 00:44:08 If it’s from listeners and nothing more. Delighted. And if anybody thinks, well, he’s missing something he’s not talked about that he’s missing. No, please tell me what it is. I would love geology to be incredibly important. I would love all you listeners to have to study geology.
Alex Maltman 00:44:26 So if I am missing something and geology is important after all, and it may turn out to be so in the fullness of time as science progresses. That’s the nature of science. I just can’t see what direction that might be. But if somebody does want to suggest I’m missing something, I’d be delighted to hear it. But any questions? Any queries discussion points? Yeah, I love it I love it.
Natalie MacLean 00:44:52 So folks you can email me. I’ll put you in touch with Alex if you have a question along that vein, you can email me Natalie at Natalie MacLean. Com and I will connect you. Alex, thank you so much. This has been wonderful. I have learned so much. My mind is throbbing in a good way.
Alex Maltman 00:45:08 Like so is mine.
Natalie MacLean 00:45:11 That’s because I kept you so long. But thank you so much. I really appreciate this. Thank you for the work you’ve done and for the clarity you bring to this subject. We really appreciate it.
Alex Maltman 00:45:21 Okay. Absolutely. My pleasure, Natalie, and thank you everybody for listening and watching.
Natalie MacLean 00:45:27 Oh, cheers and goodbye for now, Alex.
Alex Maltman 00:45:29 Cheers.
Natalie MacLean 00:45:35 Well, there you have it. I hope you enjoyed our chat with Alex. Here are my takeaways. Number one, how much of what we perceive about the taste of wine is actually shaped by psychology? As Alex explains, it’s psychology that makes people think, oh, this is a heavy bottle. It must be a classy wine. And all of the other things that affect our perceptions of taste. There are a lot of them, he says. And it makes you wonder how there’s any consistency between wine tastes. And I would add, wine critic notes. The answer is the suggestive power of the placebo effect. So for many wine drinkers, especially those who might lack confidence about wine, if some expert says, well, you’ll be getting these notes and this and that, and then of course you say, yeah, yeah, I’m getting that. This often overrides other factors like music or weight of the glass, shape of the glass, or if there are flowers in the room and what colors, etc. rather like a clinician saying, take these tablets, you’ll feel better.
Natalie MacLean 00:46:35 So if the Wine authority says you’re going to taste vanilla, guess what? You’re getting vanilla. Number two, our vineyard soils important contributors to a wine’s taste profile. Alex says there was a test with geologists who had several growers plant for different grape varieties, each in different soils, and then they identified the grapes uniformly, then sent the finished wines off to a completely independent expert taste panel. Was there any commonality between the anonymous wines? Maybe to a small extent, he said. But it was really all about the grape. Nothing came from the soils. They repeated the experiment and this time they used 3 or 4 different yeasts. Again, any commonality. And again they could and they were able to put the wines from a certain yeast in a group. So yeasts made a difference. They didn’t know what the yeast was. But yes, these wines have something in common. Soils did not come through as a factor at all. So as Alex says, the claims just don’t hold up. And number three, why do so many wine producers then highlight their soils as a unique factor, making their wines stand out? As he says, they’ve got to sell wines.
Natalie MacLean 00:47:47 It’s a competitive business and growing vines and making wine, well, that’s easy to replicate anywhere given a decent climate, but the soil is the only factor that’s difficult to reproduce in other regions. So whatever growers find, they’re going to say our soil is special. It’s a great selling point. And number four, where do minerals we taste in wine originate from? In agriculture, the farmer is extracting a crop every season, Alex explains. So if they just keep doing that without giving anything back, the soil becomes depleted. The dust storms of the American prairies in the 1930s were a good example, because they over cropped vines don’t need much in the way of nutrients, which is why they grow on very barren looking soil. But the organic matter has to be there to some extent. And so farmers will let foliage and grape stems, etc. rot down on the ground. They’ll let weeds or cover crops decay in place. They might spread a bit of pumice in the vineyard, so the vines get the organic matter it needs.
Natalie MacLean 00:48:56 When some wine commentators or critics are saying, yes, I’m getting these minerals from the soil and getting graphite and flint and talc because it’s been taken up by the vine root and transmitted to the vine, he said. It doesn’t happen that way. Organic material cannot absorb inorganic material, and in any case, any nutrients that are taken up by the vine route and make it all the way through to the finish vine, almost certainly, he says. Originated in the humus in the show notes. You’ll find the full transcript of our conversation with Alex, links to his website, and book the video versions of these conversations on Facebook and YouTube live, and where you can order my book online no matter where you live. If you missed episode 334, go back and take a listen. We debate whether chalky soil is really the secret to great English wine, or whether it’s just clever marketing with author Henry Jeffreys. I’ll share a short clip with you now to whet your appetite.
Henry Jeffreys 00:49:54 I think it is overrated. I think it was the story that sold.
Henry Jeffreys 00:49:57 So it was same soil as champagne. Same grapes, same techniques, but English. There was like a rush for chalk. People thought chalk sexy. And it was sort of. It was a good marketing angle, and they thought that it was the best place. But in recent years, people, especially with the rise of Essex, people thought that Essex was just clay. You know, you can’t grow grapes there. It’s too sticky. And actually people have realised that you can. So I think what’s far more important is, you know, your aspect, the fact that it’s not too high above sea level because it gets colder, but then not too close to the sea. Problems with frost. Sunshine. Rainfall. I think almost everything else is more important than whether it’s chalk or clay. And then once you’ve got everything else right, then you can argue about that.
Natalie MacLean 00:50:48 You won’t want to miss next week when we chat with Sarah Jane Evans, master of wine and author of the new book The Wines of Central and Southern Spain From Catalonia to Cadiz.
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Natalie MacLean 00:51:57 Five seven. Thank you for taking the time to join me here. I hope something great is in your glass this week. Perhaps a wine that has terrific minerality, whatever that means for you.
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