Les quatre saisons du vin – Manuela Brando de Lachapelle (English translation). This published with the permission of the podcast hosts.
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This is part one of a transcript of the Aug. 1 episode of The Four Seasons of Wine podcast in French, which has been translated into English. [The original podcast, in French, is here, It is translated below by Claude.]
[If you prefer the audio, you could also try listening to it while using with Google Translate.]
I have taken the liberty of sharing this in the U.S. in English with the sole intention of spreading the knowledge from the Lafite study and to support of the podcast hosts’ new book (published before their interview with Lachappelle took place). It is a wonderful podcast series.
Podcast Intro: Wine lovers, our specialists César Compadre and Mathieu Hervé invite you to join them through the seasons to talk good bottles, the Bordeaux vineyard and wine news. In each episode, they guide you through the industry’s must-see events, break down what’s at stake, and share their insider tips (to be enjoyed in moderation!). They also host major figures from the wine world for in-depth interviews.
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The hosts’ questions are in bold. The guest’s answers in plain text. I have inserted a few boldings in italic in the guest’s answers.
Episode Introduction
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Hello, I’m Mathieu Hervé. You’re listening to Les quatre saisons du vin, a podcast from the Sud-Ouest newsroom. Thanks for being here. Enjoy.
Before we start this episode, a little self-promotion. This podcast has been running for eight seasons, and it is now going from spoken to written. From May 15, you’ll find the book drawn from Les quatre saisons du vin in bookshops and newsagents. It is published by Éditions Sud-Ouest and titled Où va Bordeaux? (Where Is Bordeaux Headed?), because that is the common thread of our dozens of interviews with the women and men of the Bordeaux wine world
It’s a stocktaking of the vineyard’s situation on the human, political, economic and cultural fronts, in the words of the people who came to speak at this microphone. César Compadre and I hope it will modestly feed the ongoing reflection of professionals and enthusiasts on the place of wine today. Thank you for listening to us and supporting us for eight seasons.
Once more, the details: Où va Bordeaux?, 250 pages, €19.90, Éditions Sud-Ouest, in bookshops on May 15.
And now, on with the conversation.
I quote: “Viticulture, an activity closely tied to French civilization and the French economy, must now adapt to a world of limited resources.” Close quote. That is the first sentence of a thesis titled Biodynamic preparations, professional perception, and study of their impacts on the physiology of the vine and the grape berry. We’ve been told, in scientific and university circles, that it’s a great thesis, defended in Bordeaux, that will become a reference on wine and biodynamics. Its author is at our microphone. Her name is Manuela Brando de Lachapelle, and she is going to explain it to us.
Hello, everyone. You’re listening to an episode of season 8 of Les quatre saisons du vin, the podcast from the Sud-Ouest newsroom that tells the story of the wine world, revisits its major events and tries to decode their stakes. I’m Mathieu Hervé, and I’m here with César Compadre, head of the wine desk at Sud-Ouest [”rubrique 20” in the source]. Hello, César.
Hello, Mathieu. Hello, everyone.
And we’re welcoming Manuela Brando de Lachapelle. Hello.
Hello, Mathieu. Hello, César.
Let me introduce you briefly; I’ll correct myself if needed. You were born in 1989, in Bogotá, Colombia. You arrived in France in 2007 and have been based in Bordeaux since 2013. And I want to stress one point right away: you are a scientist. You trained as an agronomic engineer and hold a doctorate in oenology, with a thesis defended in 2025 at the Institute of Vine and Wine Science (ISVV) in Bordeaux. You are Director of Research and Development at Domaines Barons de Rothschild Lafite. I’d point listeners to our recent episode with Saskia de Rothschild about the estates.
Today we’ve invited you to talk about a subject that is interesting, often divisive in the vineyard, and sometimes caricatured, or at least it was not long ago: biodynamics. We’ll talk about your approach, your work, what you do at Lafite. We’ll also talk about global warming, viticulture, agriculture, and wine in general.
A quick note: we’re recording in early July, and this episode will air in August. I mention it because we have already lived through two heatwave episodes, and we may well see more soon. It’s important to state the context.
The thesis, Steiner and the roots of biodynamics
Biodynamics: skepticism and curiosity. Those are the two words that come to mind. When you’re out in the field a lot, as I am, you hear about biodynamics very regularly: in estates that are certified biodynamic, in those that are interested, in those that criticize it. Pontet-Canet, Fonroque, Palmer, Climens, to name just a few. These are châteaux we’ve written about a lot in our columns and elsewhere. And one idea strikes me: if you set the number of press articles and conversations about biodynamics against the number of properties actually certified, the gap is striking. We’re talking about barely a few dozen properties certified by Demeter or Biodyvin, the two certifying bodies for biodynamics, and about a thousand certified properties in viticulture worldwide [figure as given in the source]. So it’s a subject that is often put forward and studied, yet in the field there are rather few certified businesses. But where the interest lies, I think, is that biodynamics raises many questions about soil life, about work, about the interaction between people and their universe, and those interactions go well beyond business certifications. What’s interesting is that it opens the mind.
Let’s open the mind, then. Before we begin, Manuela Brando de Lachapelle, we’ll give you an exercise academics are generally well practiced at: explain your thesis in 30 or 35 seconds.
Well, I completely agree with César. There are tons of articles giving opinions on biodynamics. But we also noted that there were very few scientific articles on the subject. So one of the aims of my thesis was to speak about it scientifically, in particular about the biodynamic preparations, which are only one element among others in the biodynamic method. The aim was to start with a preamble on how biodynamics is represented in the French wine sector, so as to work on those attitudes of skepticism and curiosity that you can observe. The second aspect of my thesis was to look at the impacts of these preparations on the plant’s physiology: growth, water status, berry ripeness, fertility. The aim was to do it in the open field, so we did it at Château Lafite Rothschild, with the expertise of course of the Institute of Vine and Wine Science, combining field approaches and laboratory approaches, but always keeping in mind that the results should be applicable in the vineyard. That way my colleagues, and all our peers around us, have the elements to decide whether or not to adopt the preparations in their practices.
A scientific analysis of practices. And to start this conversation on solid ground, let’s immediately address what is often biodynamics’ controversial side. Pell-mell: there’s esotericism, there’s the guru figure, there’s the drift, in quotes, almost sectarian, there’s astrology, in other words anthroposophy. And above all there’s its creator, the Austrian Rudolf Steiner, 1861 to 1925. Explain the historical roots of this movement to us.
Sure. Rudolf Steiner was an Austrian philosopher, open to many currents. He isn’t the first philosopher to talk about nature. He raised various points related to agronomy in the interwar period, when chemical products were arriving in agriculture and harming soil fertility and crop yields. So he laid down precepts, and the unfortunate thing is that he died a year later and couldn’t justify what he had said. These precepts are collected in a book called the Agriculture Course, which is very hard to understand. But what’s worth looking at, and there are interesting scientific articles on this, is that gathering, those lectures by Rudolf Steiner. The group listening to him was made up of very varied professionals, often scientists and researchers. You have to know that Steiner said what he thought, but he insisted on the importance of experimenting, publishing the results and sharing them. So in fact it is the experimental scientific approach we know today. We sometimes forget that. And of course, because he was a philosopher, that group began to be singled out, which made it feel shut in. That’s why people speak of a sect today. But when you look at how the French government [body that monitors sectarian drift] defines a sect, what I know of biodynamics in agriculture and viticulture doesn’t tick all the boxes of a sectarian drift.
It is indeed a community, one that sometimes combines science with a certain empiricism and certain spiritual aspects. But there is in no case a sectarian drift with everything that implies in terms of control or physical or psychological aggression. So yes, it divides the sector. Since there is little scientific knowledge, there are many opinions. Today the sector is split between detractors and the convinced. So the objective of my thesis was to see whether it was only that, or whether there was something more interesting than this debate, which today doesn’t let us move forward.
Let me add two or three details. It’s a theory that was, in quotes, developed mainly in Austria and Germany, so nothing to do with the oceanic climate here, by a man who didn’t drink wine, or hardly.
He didn’t mention wine at all, because indeed he didn’t drink it. So what we use today in viticulture has been adapted, and I think it’s important to adapt what was said. Today there are some, notably the category we call the convinced, who stick to Rudolf Steiner’s specific recipe. And it seems important to me, in the context we’re living in, to adapt these practices and let them evolve. And viticulture has made these methods its own.
To complete the picture, I’ll mention Corinne and Jean-Michel Comme, whom we’ve already had on the show, and who also talked to us about biodynamics. I don’t know which current they belong to compared with you; perhaps you can tell us. In any case, this is the starting point of our conversation. To sum up, and I’ll ask for your definition: biodynamics has a holistic dimension.
Exactly. One of the founding principles of biodynamics is to consider the farm as a living organism. Like a human body, the farm is made of different organs: the vines, mixed cropping, livestock, the animals, the human being, and the surrounding environments, more or less near, more or less far. The idea is to make all these organs interact so that the farm’s physical body and energetic body interact well and stay healthy.
All this looks a lot like the notion of agroecology we use today. The only difference is that agroecology speaks of services provided by nature and of interaction between the environment and the farm. Biodynamics goes further: it speaks of distant environments too, but above all of the central place of the human being in this ecosystem. And it seems very important to me to put the human back at the center of the farm, to return to the peasant common sense our professions should have, so that the human is the conductor of this agricultural organism.
Resistance, the preparations and the thesis results
In an interview you published, I believe on the Domaines’ website, you said: what interests me in my thesis and in my work is understanding why some changes pass easily and why others provoke resistance, mistrust, even mockery. Concretely, in your practice, what seems to provoke that resistance, mistrust and mockery in this approach today?
It’s the aspects you mentioned earlier: the esoteric side, the side that isn’t justified by science. And I realize that in French culture in particular, the culture of Descartes, you need scientific validation in order to believe in a subject. In my twelve years of applied research, I’ve found that changing mindsets is the hardest part of getting my colleagues, and winegrowers, to adopt a given practice. So it’s not so much the tools, or the products, or the supply of certain resources; it’s really a change of mentality. I love these subjects that call for collective transformation, an adaptation of practices, stepping off the beaten track a little. They’re the most complicated, but the most exciting.
You talked about farms. Let’s take an example: an estate working in biodynamics. Tell us how it differs from conventional viticulture and from organic viticulture. The preparations, which you mentioned earlier: what is a preparation? We talk about biodynamics, we look at lunar cycles and so on. Give us a typical picture of a biodynamic winegrower. What are they thinking about, and what do they put in place that their colleagues don’t?
Rudolf Steiner spoke of a path of knowledge. I think a biodynamic farmer or winegrower is an experimenter, and every day they ask themselves: should I do this? With the climate I have, my employees, my context, is it relevant to do it or not? I’ll launch experiments, I’ll question myself. For example, I’m a great admirer of Château Palmer, because indeed they use the preparations, and my thesis worked on those preparations.
You need to explain what a preparation is.
The preparations are either mineral or organic. The organic ones are based on cow manure or on plants. The two main preparations are horn silica and horn manure. Horn silica is crushed quartz that you put in a cow horn and bury from spring until autumn. Horn manure is cow dung that you put in a horn and also bury for six months. These preparations undergo a transformation, a fermentation, in the soil. When they come out, they’re completely transformed; you dilute them in water and apply them to the vines.
On the foliage.
On the foliage. We analyzed these preparations in the laboratory. They’re teeming with microorganisms. My thesis didn’t deal with the microorganisms, but it would be very interesting to study the effect of the microorganisms applied through these preparations.
During those six months, what’s in the horn changes completely?
Completely. We ran trials of this transformation on the cow manure, which isn’t very pleasant to go and collect. We put it in terracotta containers, in plastic containers and in horns. And the only interesting transformation is the one that happens in the horn. We thought terracotta would work, since it’s also a porous material. But the manure didn’t break down in the same way.
The horn manure that comes out of the ground looks like humus. It has a modeling-clay texture, and an aroma [the source reads “super bronde”, unclear]. It has nothing to do with the manure we buried at the start.
And when you spray it, what does it do on the foliage? What does it bring?
Well, horn manure is normally sprayed on the soil.
On the soil.
On the soil, with a coarse-droplet spray. Horn silica, on the other hand, is applied to the foliage as a mist.
OK. And what does it bring?
We can get into the results of my thesis.
Let’s go, then. The conclusions, the results, your observations.
I admit it’s not easy to imagine that you put horns in the ground and it will make good wine.
Not at all. It’s quite counterintuitive.
And I’ll come back to the farm in a moment. You asked me what the farm is. It’s important to talk about the preparations, but we mustn’t forget they’re the cherry on the cake.
For me the most important thing is to have this organism that interacts well and is healthy. So, back to the results of my thesis. Some aspects of the vine’s physiology are not affected: the phenological stages, the leaf area, the vine’s storage of reserves. Its general physiology isn’t impacted.
Other aspects do change. We observed better water-use efficiency. That is, when you measure water stress, you see that the vines in biodynamics are a little more stressed. But alongside that, stomatal opening isn’t affected. There’s no triggering of certain hormones, such as abscisic acid, in the event of stress. Stomatal density is identical. Leaf area, as I said, isn’t affected. So in fact the vine does just as well with a stronger water constraint.
Then we observed that it’s less sensitive to disease attacks. These are things we had already seen in the field before my thesis began, over 2018 to 2021, and again during my thesis, in 2023 to 2024. We observed that the vine has a lower intensity of mildew attack.
That’s counterintuitive, because we have in mind the idea that biodynamic estates have rather very low yields.
I’d like to take up that subject, because I don’t think phytosanitary protection is the source of yield loss. I think that when you go organic, the soil work strongly reduces yields. At Lafite, for example, we have always worked the soils. So when we went organic, we saw no yield loss linked to phytosanitary treatment, since the yield loss from soil work was something we never experienced. If the phytosanitary treatment is done well, there is no yield loss.
So when you apply the biodynamic preparations, there’s less intensity of pathogen attack.
We’re opening lots of doors here. We can come back to yields if you like. The farm, we’ll come back to as well.
I’ll stay on the thread. In other words, what you’re telling us is that the whole system is slightly shifted. The vine grows a little more slowly, defends itself better, and the grape ripens a little differently. You observed all that at Lafite, right? If I understand correctly, what is the protocol you set up?
It’s important to talk about this, because it’s a thesis done at Lafite, in a very particular context, with a protocol of our own. We have practiced biodynamics since 2017. We were accompanied by two advisers, Jacques Fourret and Nicolas Jamin, who taught us how to do biodynamics. We adapted our preparation protocol, and today we apply nine preparations a year. That’s a lot, when you consider that labels like Demeter or Biodyvin sometimes require just one silica and one horn manure. We apply nine preparations.
Over what area?
Today at Lafite we apply these nine preparations on 15 hectares. My thesis focused on four hectares. Of the nine preparations, six are silicas and three are horn manures. So I can’t tell you today that this is generalizable, since few biodynamic winegrowers apply that many preparations. But we wanted to push the system to the extreme in order to draw interesting conclusions during this thesis.
Yields, soil life and resilience
Now we can come back to yields, since you mentioned Palmer. César, do you want to jump in?
Just to say that it’s a matter of professional, or public, common knowledge, I don’t know how to put it, that estates practicing biodynamics get low yields. Or even, as we saw at Pontet-Canet one year, when the season starts badly and the phytosanitary treatment is poor all season long, the harvest is compromised. So it’s counterintuitive, at least to me, to think that working in biodynamics secures yields. So you’ll need to explain. Maybe this will send lots of estates into biodynamics, I don’t know. Because to do biodynamics, we haven’t said this yet, you first have to be certified organic.
Exactly, and that’s very important. At DBR Lafite we have worked organically since 2016, by the way, with trials so as not to make mistakes. We learned a lot about the timing of treatments, the doses to apply, and spraying that has to be impeccable. And we found that if organic is done well from A to Z, there’s no reason to lose the harvest. If you have the firepower, if you can intervene within a day, there’s no reason.
On weekends too?
On weekends too, with an on-call system and so on. These are all things we learned along the way, and today we know how to manage despite Bordeaux’s difficult climate. So I’m convinced that if organic is done well agronomically, there’s no reason to lose yields, and on top of that, the biodynamic preparations are meant to do good and not reduce yields.
Just a remark, Manuela Brando de Lachapelle, because we’ve heard this enormously over the years at this table, elsewhere, in magazines, in interviews: yes, but organic and biodynamics are simply not suited to the oceanic climate of Bordeaux. Between the lines, what you’re telling us is that the problem isn’t there. Could you expand on that?
It’s true. Take a year like 2024: we had to spray 25 times because of abundant rain. Of course you ask yourself the question, and you say, we’re passing over the vines, using fuel. It’s not great to pass 25 times.
On top of which you compact the soils: fuel, labor, tractors, soils, there are only drawbacks.
Exactly. But in a year like 2025 [as in the source], some of my colleagues this year are finishing at under 2 kilos of copper per hectare. They haven’t even sprayed ten times. So yes, there are very complicated years, and there are other years. With climate change, maybe we’ll get less rain and maybe it will adapt well.
What is true is that for soil fertility, for the health of our ecosystems and of our employees, organic seems to us today to be the best option.
To finish on yields, since we studied them in the thesis: you know the vine’s reproductive cycle runs over two years. We analyzed the different stages: floral induction, fruit set, fruit growth. We studied all the components of yield. We saw that biodynamics would have an impact only on berry growth, because the berry skins are harder and less porous. On a calculated yield, there would be a 10% loss.
On a calculated yield.
Yes. I amused myself by measuring the yields and comparing them with what I had calculated. When you measure yields, there’s no difference. When I calculate them, I get this small 10% loss.
In biodynamics, a 10% loss.
On my thesis plots.
Because of the berry skins.
Because of the skins, which limit the swelling of the berry. So we get smaller berries and looser bunches.
And that 10%, when you look at it, is the year-to-year fluctuation in yield. It’s also all the measurement errors you can have in the vineyard.
It’s what you can lose through crop thinning, through sorting. So winegrowers don’t consider that 10% a big loss. And when you see alongside it that mildew is reduced, that the skins are more resistant to botrytis, and the prophylaxis you get because the bunches are looser, that 10% is quickly compensated. So you have to distinguish between yield loss from the soil work that organic involves, yield loss from agronomic mistakes when doing organic, and this small 10% loss you can have because the berries are smaller.
Explain this notion of soil work. You speak of yield loss in connection with soil work. What exactly is it?
Well, back when, and it’s still the case for some winegrowers, you chemically weeded, you had vines...
Weeded across the whole vineyard.
Across the whole surface, or just on the row, you had vines with shallow root systems.
The roots don’t go deep.
The roots go down less. And so when you go organic, you pass over the vines with mechanical tools to work the soil.
You stop the weeding and the tractor takes over.
Exactly. When you go organic, that’s what happens. This mechanical work can cut roots, and in that case you see that the vine suffers. So there are yield losses at the start.
In the first years, while the roots go deeper.
Exactly, and while the vine regulates its physiology.
So there, the yield loss is tied to soil work and not to phytosanitary treatment. That’s the big difference.
That’s my view, based on the experience I’ve had. Because beyond that, if the soil work is mastered, you’re past that stage of rebuilding roots, and you do your phytosanitary treatments well, there’s no reason to lose your yields.
There are winegrowers who want to go organic. They need to know the first years will be very difficult.
That’s the case, and unfortunately, with the economic context we’re living through today, many winegrowers in conversion and in organic are going back to herbicides, partly for cost reasons, since mechanical work is quite expensive. It costs much more to work organically than conventionally.
We’ve been talking about the impact of the practice on the vine and on the berries. We talked about soil work. Tell us about soil life. What did you observe? And, because it’s a test that makes people smile but surely says something, there’s the famous underwear test. Do you do that?
We did it for a long time. We did it for five months.
Cotton underwear?
Cotton underwear. You’ll have to explain that.
So we bury organic cotton underwear, which is important, and not colored. We realized that mattered too. And we keep the elastic, because the elastic won’t be broken down by the soil microorganisms, whereas the cotton will. We bury it and wait, and then when we dig it up we find the elastic with a larger or smaller piece of underwear attached. That gives us a percentage of degradation, which is supposed to correlate with the biological fertility of our soil, in other words the microorganisms present.
And beyond the anecdote, as a scientist, what did you find in your soil?
My thesis didn’t work specifically on soil microorganisms, but we sent samples to the University of Kassel, which does studies called substrate-induced respiration.
Kassel is where?
In Germany. Notably the researcher Jürgen Fritz, who specializes in this field. He found that the microorganisms in our soils have a low metabolic quotient. It’s as if our fungi and bacteria were great athletes with a lower basal respiration, a lower resting heart rate, who can therefore be in very good health while using fewer nutrients. That’s a first finding.
I also sent soils from my trial plots to INRAE in Dijon, notably to Lionel Ranjard and the EcoVitiSol program. He found that our biodynamic soils do better in terms of microorganism abundance and the bacteria-to-fungi ratio than soils that are purely organic.
And since I was seeing that, I also sent samples to another INRAE Dijon team, notably Antoine Sporthes, who works on mycorrhizae. He also found a difference in mycorrhizae between the biodynamic soils and the others. So I find it quite reassuring that other scientists are finding results too, notably on this aspect of soils.
So the soils on the biodynamic plots are sturdier, more solid, more resistant; they’re in better shape.
Exactly. That’s why we speak of resilience and homeostasis, meaning they change more slowly when a stress is applied. And today, God knows there are biotic and abiotic stresses, so it’s valuable to have soils that are resilient.
But how long does it take to get to this kind of soil? It takes years, I imagine, to go from conventional to this kind of result.
Well, I think going from conventional to organic is already great. Bringing in grass cover and organic matter contributes a lot. After that, I can’t tell you how long it takes, but we did these analyses ten years after the start of biodynamic applications.
Ten years after the first applications?
Ten years after the first preparations. And biodynamic practitioners say, empirically, that the effect is cumulative. It’s not in a single year that your microorganisms will settle in. What’s needed is small doses, small vaccines given every year, through the microorganisms brought in with the preparations.
Sometimes we visit estates where they tell us they’ve never used herbicide across the whole vineyard. I imagine those soils are doing much better. Are they in the same category as what you’ve just explained?
I imagine so. Those are solid, sturdy soils. It depends on how they’re worked. Today, notably in the Médoc, the rows are so narrow that the soils get worked a lot. And soils that aren’t covered get very hot. With the heatwave, you can reach 70 degrees [Celsius] on uncovered soil. The bacteria and fungi don’t like that. There’s oxidation. So it depends. But Lafite has never been weeded. That’s an asset for us. And comparing the same Lafite soil with and without biodynamics, the biodynamic soil is more resilient than the organic one.
END PART ONE
TO BE CONTINUED WITH PART TWO
