I’m keenly aware of how much I don’t know about making wine. I try to learn as much as I can from the very talented people I have the privilege of meeting and speaking with in the course of my journalistic adventures. But I’ve still got lots of gaps. Once of the biggest has to do with the really down and dirty aspects of viticulture.
That’s why I was quite impressed and engaged by a presentation at the recent New Zealand Pinot Noir 2013 conference by Dr. Emmanuel Bourguignon. Bourguignon is the son of arguably the two most famous viticultural soil scientists working today: Drs. Claude and Lydia Bourguignon. These two agronomists, along with their son, run one of the most successful and respected viticultural consulting companies in the world, and are widely regarded as leading experts on wine grape agriculture. Most notably, Dr. Claude Bourguignon was one of the first people to both measure and understand the relationship of microbiological activity in the soil to the health of grapevines. It was Bourguignon who famously pronounced the sands of the Sahara were more microbiologically active than the soils of Burgundy.
His son Emmanuel came to Wellington, New Zealand to provide some perspective on ideas of terroir, and offer advice to the industry on how to think about the future. In doing so, he provided a very interesting primer on some of the key variables in viticultural practices, and how they affect wine quality.
I found his talk fascinating, and I learned some pretty interesting stuff. So I thought it might be of interest to my readers as well.
What follows is my usual attempt to capture the lecture as it was given. I had to paraphrase, summarize, and miss certain parts of the lecture, and obviously you’ve not got the benefits of the interesting photos and charts he provided, but I think there’s some interesting stuff below regardless.
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I would like to thank the organizers for giving me the opportunity to be able to speak in front of you. Before I start, there’s a few things I have to acknowledge. With all the speeches this morning, I have tough acts to follow, and my french accent doesn’t help. Despite spending 4 years here, I’m sorry I didn’t puck up the Kiwi accent. I saw the video yesterday after Mike’s speech where the australian’s were offering their thoughts on Kiwi wines, and I’m wondering which is worse, an Australian accent or a French one? I’ll stick with French.
I’m sure many of you know my parents and wonder why they’re not here, and wonder why you have to put up with their son. I’m wondering the same thing.
When I asked them, the organizers said “we need some fresh blood,” and I was immediately reminded of the gladiators entering the arena.
My speech is going to be more technical. I’m going to focus on viticulture. My goal is to give you ideas to help you maintain your forward momentum. We’ve had many discussions so far at this conference about authenticity, place, etc. But we haven’t heard much about viticulture and I’m going to fill that gap. I will try to challenge you, and get you unsettled. Show you some of the pitfalls in how grapes are grown today. I want to help you avoid them or to think about them critically.
The key thing, our main goal, is to try to look after your young vines and give them that necessary longevity to achieve a real sense of place.
In the lab we get to see a lot of different vines, to see them growing in many different climates, regions, and landscapes. I find that to be a privilege. You get to observe different problems, and when you get to a new country you can try to come up with a best idea for how to grow grapes there based on your experience.
For New Zealand, there are two ways forward. There is the easy way, and the long way.
The easy way consists of dealing with four things: irrigation, canopy management, planting density, and rootstock quality. We will discuss each of these.
I’m going to try to show you why irrigation can be a problem. The grape vine is a very resilient and adaptive organism. It is capable of growing in areas you wouldn’t dream of them growing without irrigation. It really gets you thinking to see vines growing in Lebanon, Turkey, Sicily where sometimes there is nothing but rock.
The grape vine — and I’m going to use a fancy word here — displays phenotypic plasticity. This is a fancy way of saying that the vine is lazy. It will always try to find the easiest way to maximize the benefit from any resource. If you give it water, it will not try to find it on its own. If the vine doesn’t get heaps of water, it will spend more energy for root growth to find water.
[He shows a picture] These vines have been heavily irrigated. You can see that because they have easy access to water, you get a big mat of fine roots in the first 40 to 50 centimeters of soil. This is a problem. Especially in New Zealand. You have very young soil. At the most your soil has only been cultivated for 300 years. You haven’t had, like us, four or five thousand years to stuff them up.
The first time I came to New Zealand, I was amazed at the vigor of the soil. It’s packed with minerals. The most fertile horizon in the soil is the first 30 to 40 centimeters. That’s where you have most of the organic matter. If your roots stay in that horizon, they get access to that food.
One of the pitfalls of irrigation is that it generates this big canopy. There are some good reasons to get big canopies of course. There’s generally in the wine industry been this tendency to increase the canopy, increase photosynthesis, generate more sugar, and therefore more flavor. When you get very little sun that’s valid. But when you’re in New Zealand, and in most regions you get amazing amounts of sun. You have amazing luminosity. Photosynthesis is not really your limiting factor.
The more photosynthesis you have, the more you drive towards the varietal characteristic of your grape rather than the mineral component of your terroir.
[He shows another photo]
Here’s a picture of non irrigated vines trained in the goblet method. You can see there are these big roots going down. We dug this solid pit and found roots deep down 3 meters or more. You can get good growth downwards without irrigation.
I want to use another big word: exotropy. This is the ability of a plant to go around obstacles, or when it gets into an indurated (impermeable) layer to get a fine root into a crack. We get lots of people saying they feel like they need to rip the soil and do heavy work to give the vine the ability to get down into the soil. We don’t give enough credit to the vine. We need to believe, and have the faith that the plant is capable of wonderful things.
Why are shallow roots not compatible with making wines of terroir? The deeper you go in the soil the more distinct your mineral makeup is. From a nutrition point of view the vine can get carbon, hydrogen and oxygen from the canopy. But in the soil the vine is going to pick up more than 20 distinct and separate elements. All these mineral nutrients are essential in all the biochemical reactions you get within the tissue of the plant. Some of these reactions are driven by enzymes that need cofactors and these are usually essential elements: manganese, copper, iron, etc. You’re going to get these from the soil.
In short you want to get these vine roots down to the level of soil we call the C horizon. If you look at all the ancient viticulture manuals, you see that people have always been tilling the soil, and working the shallow root system. They didn’t do that for the fun of it. It’s hard work as all of you know.
The vine is the plant version of the dog. It is the plant that has been domesticated the longest. We prune it, we manage it. When you work that shallow horizon and get rid of shallow roots. When you do this, the tap roots start to lignify. This lignification profess creates a hard layer around the outside of the roots like a bark, and they thicken. These roots aren’t efficient at picking up moisture. And that is a good thing. If you get rain just before harvest, these kinds of roots won’t pick up much and your berries won’t swell.
I want to touch on density of planting. I’ve seen soil in NZ that could benefit from being planted with higher density than it is now. One of the problems you’re facing now is that you don’t have access to machines to work with high-density vines. If you don’t have the machines to work that shallow soil, you’re going to have to use herbicides to control weeds, which isn’t a great idea. You’ll either need to import these machines, which may be too expensive, but you may want to work with local manufacturer to produce such machines.
And of course there are some soils that could not support higher density. As you keep moving forward try to keep that in mind. There’s the reality of how your vineyards are set up, but in the future think about density.
I want to talk about rootstocks. You are starting to use good rootstocks. That’s encouraging. You need to try to shy away from the vigorous rootstocks. You don’t need to increase the vigor of your vines. It’s better to stick with less vigorous rootstock. These naturally tend to produce less and bigger, more plunging roots. A lot of the vigorous rootstocks we have in Europe, they are adapted for active lime in the soil, but for the most part you don’t have active lime, even when you do have limestone.
OK, so those are the easy things to do. Now let’s talk about the Long Way towards really expressing terroir. This is about the quality of your plant material, the choice of grape variety, and better identification of terroir, in general. Which is to say you can’t just say, “I think that looks perfect for Pinot Noir” and plant your vines.
But first let’s talk about the plant material. The vines we plant are derived from centuries of massale selection. Although there are some interesting things about clones, planting solely clones you just don’t get complexity. Genetic variation is a lot smaller with clones than massale selection.
Of course, you have another situation with your biosecurity control here. You can’t just talk to a French guy, get some cuttings, and jump on a plane with them. So you should start your own massale selection program. It’s easier to do with Pinot Noir than with other varieties because it is one of the less genetically stable varieties. It shows some genetic variation even among clones. So look into the vineyards, find the vines that have differences, take cuttings, propagate them and over 20-30 years you will find some that are truly adapted to your conditions. This is called reverse selection. It is possible, but it will take a long time. To me you have the chance to do it.
CHOICE OF GRAPE VARIETY
Not all soils are suited to all grape varieties. There’s a great book called Wine Grapes now, that is made up of information based on the DNA profiles of 1300 of the main grape varieties in the world. What we know from this book is that there were very few founder grape varieties.
We know from the history of Europe, that when people came from all over to Burgundy, they got cuttings and those cutting moved all around the continent. They didn’t have technology, but they realized Pinot didn’t behave as they expected. They started to notice these modifications and tried to encourage that, or even explicitly to cross grapes. The founding grape varieties were established widely across Europe, and where they didn’t work, people found varieties that did. There’s been a selection that took place to determine what should be grown in which place. You’re at the same stage in New Zealand that we were in Europe so long ago. There is some work to be done to figure out where to put your grapes.
IDENTIFICATION OF TERROIR
Terroir is very complex. It encompasses many different factors, and as we all know the definitions are endless: geology, topography, climate, elevation, and more.
Out of all these parameters there is one that is extraordinary complex and hard to understand: the soil. It is a dark place. We walk on it but don’t see it. We don’t want to get our hands dirty. It is the trickiest medium to study. It is where we have this interaction between the organic world and mineral world. They are both very complex worlds. When they combine you get something even more complex. The soil is something that will influence the final results with your grape. The closer you are to the top horizon of soil, the more homogenous it is, the deeper you go the more defined and unique the soil. The deeper you go the more heterogeneous it is.
When you look at Burgundy, the things above the soil are quite homogenous. It’s pretty much the same everywhere. You can’t say the topography is different, it’s mostly east facing slopes. You can’t say the geology is different, it’s all middle Jurassic. We all just use one or two grape varieties.
So how did they end up with so many appellations? You know that when you do a blind tasting of wines grown with the same viticulture and and made with the same winemaking you can taste the differences between two different appellations. When you leave the macro level and enter the micro level there is where you find the heterogeneity. It’s all about the soil. You have to give credit to the monks who were working on faith and trying to get the best results, to have figured this out.
Empirically they worked out the nuances of Burgundy. It took them centuries. But here in New Zealand, you can speed up that process and eventually work out within a region, the heterogeneity on certain sites.
We worked for Clos de Tart. They felt they had significant differences within their 7 hectares, so they asked us to do some soil sampling and analysis. I want to show you picture of their soils.
[He shows a picture of several vertical samples of soil. They all appear the same in the top few layers but there are huge differences several layers deep].
Geology alone cannot explain soil complexity. The geologic map of Morey St. Denis says it is homogeneous, but the climats show something different.
Burgundy has pushed the notion of terroir about as far as you can go. But Burgundy is not the only place. There are many other places you find the willingness to clearly define the terror: Alsace, Rhone, Barolo, Loire. A clearly defined set of terroirs is not solely the province of Burgundy. This is encouraging. Any place in the world can define their terroir.
New Zealand has great geology and lots of complexity in its soil. But figuring it out is a long process, that takes enormous amounts of humility. It’s not always easy to have that humility and patience. There are economic realities that force us to do things faster. We don’t always have the time.
And the nature part of terroir — the soil, geology, water, soil. These can’t be controlled. It is unfair. You’re going to get this situation where you find someplace that the vista is beautiful but the soil just doesn’t live up to your expectation. That is true everywhere, not just New Zealand. Not everyone is equal. That is what is interesting.
Of course, the consumer is interested in the whole range wines and expressions of terroir. Not everyone wants to drink a grand cru. So everyone has room to do what they want to do.
We are great believes that wine is not a natural product, It is man made. Leave a vine by itself and it will soon stop producing grapes. We are using an organism that lives in a certain environment, we need to help that organism reveal and amplify the voice of that soil.
In New Zealand you have all the cards in your hands, you have to reflect about what we’ve talked about. Here’s food for thought, and good luck with your project of growing great Pinot Noir in New Zealand.