“ . . . I would be happy if the true meaning of terroir was more widely known and more judiciously applied,” surmised Tom Darnell, Oregon extension horticulturist stationed in the rapidly emerging wine area of the Walla Walla AVA.
This posting is made in response to questions that Tom Darnell has raised about relationships between terroir and geology. They were raised in response to the September 21, 2011 article: Soils I: Goût de Terroir and The Dirteaters. The reader is advised that the bibliographical citations for Soils I were all listed at the end of Soils II. The two columns were originally written as one, but split in two because of length.
Mr. Darnell’s questions demand a response that is too long and complicated to post as a response. Therefore, here it is for everyone to see. He is still exploring the meaning of the French term terroir, and is to be commended for persevering.
James E. Wilson, geologist
Since Darnell relied heavily on James Wilson’s definition of terroir, let’s define Mr. Wilson. James E. Wilson identifies himself as a petroleum geologist. He also has an advanced interest in wine as a consumer. I think he would be called an enophile. To my knowledge, Mr. Wilson has not studied viticulture or horticulture in a campus course, nor has he grown a grape or made a bottle of wine commercially. His connection with the Universitée de Dijon (now renamed Universitée de Bourgogne) is the Geology Department, not the viticulture or enology people.
I, too, jumped at the promise of Wilson’s book, Terroir: etc.. It was touted to be the Holy Grail of viticulture, the secret behind the superior quality of French-grown wines.
The book does nothing of the kind.
Let’s use a simile to illustrate the point. An observer watches the automobiles passing through an intersection for eight hours. He notes that slightly more than 23% of the cars are colored white. Can we conclude, then, that passing through this intersection will cause more than 23% of the autos to become white?
But that’s what James Wilson’s book does. The deep soils are thus-and-such, and that’s why the wines are so good. Where is the proof? Where is the cause-and-effect relationship proven? It isn’t. There are no gas chromatograph analyses of leaf petioles to identify a pattern of elements reaching the leaves that is directly related to the soil. There are no attempts, at the very least, to correlate appellations , such as Grand Cru and Premier Cru, with geologic structure.
Yes, James Wilson has rendered a great service to the world of wine knowledge. It is of academic interest to know what the soils down 20-40 feet are made of. But, considering that about 85% of the vine roots are in the first 18 inches, not much room is left for a lot of nutrient input from the lower strata.
Of greater interest, in Burgundy at least, are the strata of limestone further up the slope whose erosion has produced screed that washed down the slope and mixed in with clayey soils.
This situation illustrates a tendency that is all too common in the world of wine. Someone comes up with new information, probably without proof. That person is then venerated as a sage of all things that are wine. The sage is tempted to venture outside of his/her range of expertise. Worse yet, people who should know better, take them seriously in matters that are outside the sage’s expertise. Does the relentless thirst for magic measures make the wine producer and consumer more gullible?
In Burgundy, it’s marble from seashells
The soils from Dijon to Santenay are definitely calcareous (pH >8.0) and of undersea origin. The soils of Oregon’s Willamette Valley are acidic (ph<6.5) and of volcanic, and sedimentary-from-volcanic origin. And yet, vineyards in the northwestern Willamette Valley seem to be producing Pinots Noir so similar to those of the Côte d’Or that panels of experts, in blind tastings, have difficulty finding any difference in aroma and taste between the two.
One look at a graph of nutrient availability versus soil pH shows that a differing distribution of ions is available for uptake by the vine roots as the soil pH changes. Therefore, one could assume logically that a differing array of compounds would be produced by the vine as soil pH varies. That does not seem to be the way things happen in the Oregon versus Burgundy comparison, which suggests that the vine has the ability to be selective about what ions it absorbs at the root hairs, regardless of the soil pH. Wow!
Oregon has a seabed full of seashells dating back to a time when the coastline was where the Oregon-Idaho border is today. But, repeated lava flows from a linear vent near Walla Walla, Washington ran all the way to the present Oregon coastline. In the Columbia Gorge just 40 miles east of Portland, Crown Point Observatory sits atop 1,100 feet of that solid basalt. The ancient seabed has been encapsulated by these basalt flows, and is thus completely inaccessible to vine roots.
An additional consideration relating to the marble layers beneath Côte d’Or’s soils is the fact that marble is a solid rock that is impenetrable by vine roots. We call that bedrock. The only limestone inputs coming from the deep marble layer are at its shallowest edge, where the halted vine roots can absorb ions of calcium, carbon and oxygen that have dissolved into water within the soil band above it. Nearer the soil surface, the calcium carbonate integrated with the top soil horizons has been produced by eons of weathering, landslides and erosion involving exposed portions of the marble layers further up the slope.
That pretty well nullifies the argument that the seabed full of seashells deeper than the calcium carbonate content in the surface layers of soil is what makes the difference.
To the French, terroir includes the soil, the climate and topography, three conditions that are inseparable. There are some man-made inputs, too. By determining vine spacing, row direction and training system, the grower modifies the way solar radiation is received at the vine level. The vineyard establishes its own terroir by bringing the locality‘s macroclimate down to the microclimate where the vines live.
That business about terroir expressing the vine tender’s soul is a little over the top, I feel. To swallow that romantic idea, you would have to think that the grower’s worrying over whether or not the grapes are going to achieve maturity during a cool year, actually influences the terroir and, hence, how ripe the grapes will become. Huh? Being of French extraction, I understand how weird some French thinking can be. But, I don’t think the concept is embraced by many Burgundy vignerons, beyond some dedicated hyper-enviros.
Irrigation
I still want to deal with the subject of irrigation in greater depth at some future date. But, the question has been raised several times now, so we’ll present a brief comment here about its relationship with terroir.
First, no one installs an irrigation system unless they are forced to do it by a shortage of natural precipitation and/or an inadequate soil water storage capacity. An irrigation system is expensive. Drip irrigation is the preferred method because overhead systems keep the vines wet too much, encouraging growth of damaging fungus organisms. Also, overhead systems allow too much evaporation. Capital costs are: drip lines, sand filter, pump and water supply. Operating costs include electricity and maintenance.
In a moderate climate like Oregon’s Willamette Valley, most grapevine varieties require a minimum of 26 inches of water during the growing season (April 1 thru October 31). That amount can be provided by water stored in the soil as of April 1, plus natural precipitation received during the seven months. Removals of that water are: 1) taken up by the vine; 2) wicked to the surface and evaporated into the atmosphere; and 3) horizontal and/or downhill movement within the soil to soils adjacent to the vineyard.
Water received from rain can be absorbed by the soil’s water holding capacity up to its limit, and some runs off on the surface. Thus, the soil serves as a buffer reservoir between rains. The minimum water holding capacity needed for this vineyard situation is about 10 inches in the top 5 feet of depth.
If natural precipitation is not sufficient, and/or the water holding capacity is inadequate, the grower must supplement the water supply with irrigation. According to need, the drip irrigation can be run every day, or intermittently as necessary. All of the storage and absorption mechanisms work the same as for natural precipitation. Some nutrients can be applied by dissolving them in the irrigation water. This practice is called fertigation.
It is my conclusion that the presence or absence of irrigation makes no difference in the quality of grapes produced, beyond the same effects that would be produced by adequate or insufficient rainfall. Sites in the Walla Walla AVA are likely to be unfeasible for vineyard development without irrigation. It’s not a matter of good versus better, it’s one between nothing and acceptable.
The application of fungicides and pesticides has a somewhat similar effect. By preventing the leaf canopy damage asserted by those organisms, protective sprays enable production of better quality fruit and, hence, wine. The leaves are better able to perform their function of photosynthesis.
Fermentation problems caused by the presence of elemental sulfur come from sulfur particles attached to the grapeskin, the amount that was not washed off by rain or blown off by the wind.
If any of the many protective materials are applied closer to harvest than the stated waiting period, remaining material can interfere with yeast propagation during fermentation.
It can be said, legitimately, that the use of fungicides and pesticides are a good thing for wine quality, if they are used judiciously.
Acquisition of terroir
Darnell asked the question: “. . . how old does a vineyard have to be before it achieves terroir?”
All things have terroir at all times. That field of green peas has terroir. A bare piece of land has terroir. An area of highway pavement has terroir. Literally translated terroir means land or soil. The reason the term isn’t applied elsewhere is that only grapes are very sensitive to differences in terroir. One could just as well apply the term to apples, for example, if anyone cared.
No waiting period is needed to reach the “status” of terroir. The content of terroir changes as a vineyard is developed on it, and it reaches a sort of stability when the vines are fully developed and producing their ultimate yield. I said “sort of” because annual differences in the climate change the terroir and, hence, the character of the grapes
An overly vigorous vineyard has its own terroir. Generally, excessive vigor relates to very rich soil, high temperature and/or high solar radiation. Dr. Richard Smart responds by increasing canopy and fruit load to balance things out. The traditional training system in Burgundy handles the situation (caused by high vine density) by leaving fewer buds per vine at pruning, frequent hedging and fruit-thinning to bring fruit and vine into balance.
An over-cropped vineyard has terroir. The fruit will be different than for normal fruit load because of the increased demand for the products of photosynthesis by the fruit. In the current year, vine growth will be stunted because the fruit has higher priority. It is also true that the next year’s crop will be significantly reduced because less than a normal amount of the vine’s resources went into bud primordia development this year.
Photo credit: http://www.artisanvineyards.com/
As usual, excellent post on terroir Jeff.
Thank you, Steve.
. . . Jeff
As usual, Jeff tells it like it is. Great information and truth about an area few people have the knowledge and experience Jeff brings to this arena. Love the truth and the telling like it truly is. Outstanding job!
Thanks, Don. Glad to see you’re reading these “dissertations.”
. . . Jeff
Jeff,great discussion on terrior. It seems that climate is more of a factor regarding terrior than soil? Although in Burgundy, there can be two climats just a few feet apart with the same climate but taste different. Soil must be a factor. If not,wine could be made hyroponically. It’s interesting to discuss winemaking and what makes great wine great! This is the cerebral aspect of enjoying wine. To me, terrior is as much metaphysical as it is physical. To enjoy a great wine and appreciate where it’s from enhances the enjoyment. Jeff, thanks again and keep these discussions coming.
Mark
Thank you for the expression of interest, Mark. Sometimes I feel that I am going too technical for most readers.
There are many more to come, enobytes willing.
. . . Jeff
Jeff,
Regarding irrigation, you mentioned that the use of irrigation does not affect the quality of the grapes and therefore the wine. Does irrigation affect the wines ability to reflect the terrior in the way the wine tastes? In Burgundy, it’s about terrior being expressed in the wine. Do you agree with this concept? Does irrigation inhibit root growth enough to prevent the expression of it’s terrior in the wine? Do you feel that organic or biodynamic wines transmit the ultimate expression of terrior? You’ve started a great discussion. Thanks again.
Mark
Hi Mark!!
Cheers for your willingness to say who you really are!
I phrased my comment about irrigation having essentially the same effect on the grapes as natural rainfall would have, for this reason. Most grape growers who have to use drip irrigation, try to mimic the pattern of natural precipitation. The vine doesn’t care how the water got there, so long as it is in the soil to be taken up by the vine’s roots.
There is a new school of thinking about how to manipulate irrigation to make desired things happen to the vines’ performance. For example, if the grower shorts the water after veraison, the relative drought condition will force the grapes to ripen more quickly. I have reservations about how good that is for wine quality. It is a fact that the complexity and concentration of flavors and aromas becomes greater the longer it takes to go through final ripening. That’s when most of those anthocyanins are produced inside of the grape.
That’s the principle behind the current vogue for red wines: to let them hang longer to acquire the depth and concentration, then use reverse osmosis to remove some of the excessive alcohol. Or, they just bottle a 14+% alcohol wine, which doesn’t usually complement food very well. And, they have to pay the higher federal excise tax for dessert wines rather than table wines.
There are techniques in use to help further control the growth rate of green foliage. It is the use of selected cover crops to pull more water put of the ground at the right times. The different grasses and other plants offer opportunities to fine tune the timing of this tactic.
Q: Does irrigation inhibit root growth enough to prevent the expression of its terroir in the wine?
A: Yes and no. Irrigation rates that mimic an adequate water supply enable the vines to perform well enough to show their stuff. On the other hand, excessive irrigation will discourage the vine’s roots from growing deeper in search of water. Then, the vine will produce grapes based on whatever root depth is encouraged, only 16-20 inches of soil depth for example. The actual rooted depth depends on soil characteristics and the amount of water applied.
Q: Do organic or biodynamic wines transmit the ultimate expression of terroir?
A: Probably not, particularly for the latter. With those practices, the terroir is modified by the addition of whatever (cowpoop, chamomile and other herbal additives.), and these materials change the soil‘s composition (and terroir) just as fertilizers would. I think organic practices that seek to minimize the use of synthetics in the vineyard are good but oversold. Failure to control molds and insects limit the vines’ performance.
Re: Irrigation
“First, no one installs an irrigation system unless they are forced to do it by a shortage of natural precipitation and/or an inadequate soil water storage capacity.”
It is important to point out that you can only install a drip irrigation system for viticulture purposes in a wine region that allows it. It is also worth noting that drip irrigation for viticulture use has only been around for 35 years or so. In the USA and Australia the use of drip irrigation is found in large percentages of their wine growing regions. In some cases these ‘growing regions’ only exist BECAUSE of drip irrigation. We couldn’t have 2BC or Yellow Tail without drip irrigation.
In the most famous wine regions of Europe the practice of drip irrigation for viticulture is BANNED. Non-irrigated vines are the norm, not the exception as it is here in the USA and in Australia.
I’m interested in reading more about the specifics of your conclusion on drip irrigation whenever it is posted. In my opinion, drip irrigation is one of many variables that cause a dilution of vintage expression. I’d also be interested to know if you are equating grape quality with wine quality. Yes, ‘quality’ is a subjective term, so it would also be interesting to here your definition of ‘quality’ is as it pertains to grape production for the specific use of creating ‘quality’ (my assumption) wine.
As always, I find your posts challenging, as they tend to be filled with conclusions that are the complete opposite of my own. I enjoy your hyper-scientific views on grapes and wine, because I learn something new or at the very least I think more deeply about my own opinions. My enjoyment and knowledge have very little to do with the scientific method, so to read your posts helps me to consider another side.
Unless one is growing table grapes, grape quality cannot be defined without wine quality. I view the growing of wine grapes as part of winemaking: the same standards apply throughout the whole process. Quality grapes = quality wine, providing the winemaker is capable.
If the winemaker is not skilled in both technical AND artistic facets of winemaking, well, the grape quality often goes wasted.
Hyper-technical? I prefer to think of it as werll-informed, objective and “cutting edge.” You’d be surpried how many winemakers are thinking at this level, at least in this part of the country.
Jeff, I do agree with your comments regarding soil and irrigation. I havn’t thought that wine growing regions wouldn’t exist without irrigation. We were in Santa Rita Hills and Santa Maria Valley and most vineyards if not all were drip irrigated. Some of the Pinots we tasted were fantastic. Thanks for that thought. Regarding grape quality, you can make great wine from great grapes,but you can’t make great wine from bad grapes. Great grapes are only one part of the equation. The other is winemaker and his techniques. Regarding terrior,it’s more ellusive as it is scientific. I commend those winemakers who strive to show in their wines the place where they are from. More winemakers are using organic and biodynamic techniques to show this expression. Jeff,I enjoy your thought and comments. Keep them coming.
L’Chiam,
Mark
We have to stop meeting like this!
You are correct in pointing to vineyards that would never be, except for irrigation. Add to that list virtually all of the rest of California, of Central Washington‘s Columbia Valley, Southern Oregon, Idaho, Napa, Sonoma, Colorado, Texas, large parts of Italy and Spain, Australia, South Africa, etc. Have you ever enjoyed Sicilian reds? Terrific.
As to the Pinots Noir of Santa Rita and Santa Maria Valleys, you will probably find the source vineyards at high elevation where they don’t suffer from the high temperatures along the coastal cities.
Your observation about high grape quality being essential to high wine quality is right on. I am fond of saying: “If it isn’t in the grape when it hits the crush pad, you won’t find it in the winery.”
Thank you for expressing your opinions on organic and biodynamic vineyard management. Perhaps, I should add that subject to my long list of articles yet to be written.
Happy New Year!
Surely, you have caught my two typos.
well-informed
surprised
it’s the Season.
Jeff,Thanks so much for taking the time to write these informative articles and start these discussions. They make me think and appreciate wine so much more.
Happy New year,
Mark
Terroirs are not equal!
Jeff,
What are the the artistic facets of winemaking?
It is impossible to separate artistic facets from the science. In many cases, the selection of technical methods ARE artistic decisions.
Now that I’ve made that perfectly unclear, let’s consider some examples.
Timing of harvest. The grape’s state of ripeness at picking is an artistic decision. It affects the style of wine being produced. But, it’s also technical, because it is based on sugar, total acidity, pH, smell and taste, and may well dictate the parameters of processing.
Punch-down method for red wine. The method chosen affects the character of the wine, so it is artistic. But which method used, be it punch-down, gentle pumpover, or blasting with a fire hose nozzle, may depend on what kind of equipment is available, and the costs associated with each method.
Fermentation temperature. Here, again, is a factor that is both. Be it red wine or white, or sparkling, the temperature regimen imposed on fermentation will affect the wine’s quality and character.
Well, heck, what isn’t both artistic and technical?
The closest one could come to purely technical would probably be bottling the wine. But, then again, there are some choices that can be made in bottling that can affect the wine style: infusion of a CO2 spritz, and details of the filtration sequence on the way to the bottling line (pre-filtration by sheet, sterile membrane).
Barreling is both artistic and technical. What wood? Barriques or puncheons? Malolactic fermentation in tank or in the barrel. How often is the wine racked? How are the barrels selected for reserve blends?
OK. The whole process is BOTH artistic and technical. That’s why it is important for the winemaker to have “soul,” which I define as a good palate combined with the sensitivity to use it to shape terrific wines. Some winemakers are like automatons. They go through all of the processes with great technical proficiency. But, they may lack the ability to appreciate, or even care about, the consequences of their choices. Winemakers like that tend not to make great wines.
Alternatively, there are winemakers who have “soul,” but they lack the discipline to produce something approaching a consistent style of wine from one vintage to the next, even allowing for differences in vintages. How the heck can the wine consumer sommelier and distributor relate to the trustworthiness of a label under those conditions?
Jeff,
Great explanation regarding artistic and technical aspects of winemaking. I really loved the comments regarding the “soul” of a winemaker. You’re posts have been awesome and thought provoking. Keep them coming.
Mark Goldberg
I want to make clear that I did not post the January 4th posts attributed to me.
I’m not ever sure what the “artistic facets of winemaking” encompass.
We could debate whether winemakers should be considered artists.
However, that doesn’t keep me from enjoying a glass of merlot from the WW valley.
As someone who attended the Art Institute of Chicago and actually sold pieces I produced, I have to weigh in here and say that winemaking is indeed both an Art and a Science. Anyone can assemble grapes and make wine, just as anyone can throw paint on a canvas. But if winemaking was purely scientific, why not just define a rigid method/schedule and stick to it? Based on our location, pick on September 9, ferment at XYZ temperature, use a bladder press, settle and rack, blend (80% Cab / 20% Merlot, no deviating here, we have a proven scientific method that works!) fine with Bentonite, do cold stabilization at 31 degrees for 11 days, do surface filtration because we think “unfiltered” wine sucks, blah blah. Maybe some huge commercial producer might follow this method and if the winemaker deviates off the plan, they get their butt kicked by the general manager or owner for deviating off the special crap recipe. There are so many types and styles of wine and many ways to achieve each style and no two winemakers follow any one recipe to achieve the outcome. It takes an artist to produce an elixir that everyone wants to drink and cherish.
You have a lot of nerve to advertise your naturopathic medication for yeast infection as a trackback to my article. Go find a medical website and leave the craftsmen of “good” yeast strains alone.