By Joe Traynor
Grape Grower Magazine, August 2003

Ah, terroir! Although this French word (pronounced ''tare-war") has yet to make it into most English dictionaries, it is increasingly heard in wine-making circles and has come to mean that combination of soil and climate that creates a wine that is unique to an area. This area can be as large as a thousand square miles or as small as a backyard plot. Indeed, different sides of a backyard planting will have different terroirs depending on how much shade they receive and when they receive it. Because of the wide range of vineyard soils, climates and microclimates, there is an almost infinite number of terroirs.

The beauty of this system is that it allows each and every wine grower to claim a terroir that is unique to that specific vineyard - one that makes his or her wine superior to any other, including the next door neighbor. Wine labels often include a short blurb on terroir and the mystique of terroir is responsible for the extravagant prices that some people will pay for a particular bottle of wine. The most successful wine bottlers have an upscale clientele that is convinced they are purchasing a wine whose terroir cannot be equaled.

Get a group of vintners together for a summer meal and the conversation will eventually turn to terroir. If the group moves to the veranda to enjoy the sunset, the glow of good food, good fellowship and perhaps a little too much wine will cause some to wax eloquent on the subject. Some who remain silent might be found with their eyes half-closed with a contented smile on their faces, secure in the knowledge that "my terroir is better than your terroir."

Breaking it Down

When terroir is broken down into its component parts, it loses some of its mystique.

Lets start with soils, terra. There are soils of almost every color - white, black, red, brown and all shades in-between. There are sandy soils, silt soils, clay soils and every combination of sand, silt and clay. There are volcanic soils, limestone soils, soils derived from glacial till and from every other kind of parent material. There are deep, friable soils and soils with hardpan a few inches from the surface. One would think that this diversity of soils would produce a vast number of terroirs. In reality, there are only two soil factors that influence wine: soil depth and soil solution chemistry.

On deep, friable soils, grapevines will develop a remarkably extensive root system, which in turn will produce vigorous vines. Hardpan soils or shallow hillside soils, and all hillside soils are shallow, will produce a thrifty vine by restricting root growth and proliferation. Deep soils aren't always the best vineyard soils since many believe that vines must "suffer" in order to produce superior wines. Vines will suffer more on hardpan or shallow soils but growers with deep soils can mimic this suffering in a number of ways - any one of which will alter terroir. These methods can include withholding water and nutrients - which is a standard practice in France; by planting on a low-vigor rootstock; by girdling and by root pruning - either mechanically or naturally, such as by spiking the soil with phylloxera and/or nematodes - definitely not a recommended practice.

So much for soil depth.

The chemical makeup of the soil solution - the solution that bathes grape roots after a rain or an irrigation - is certainly dependent on the parent material from which the soil was derived. Red soils usually have little or no lime, or calcium carbonate, while light-colored soils often have an abundance of lime. The chemical makeup of their soil solutions can be quite different in their virgin state. Soil chemistry can, however, be changed by adding lime to low-lime soils and by neutralizing lime with acidifyine amendments in high-lime soils. Soil solution makeup can be similarly changed with fertilizers. It is theoretically possible to take two soils with widely different chemical characteristics in their virgin state and make their soil solutions almost identical through the judicious application of fertilizers and amendments. It is the chemical makeup of the soil solution surrounding grape roots that determines the chemical makeup of grapes, and later, wine. When virgin ground is planted to vineyards, its soil chemistry will change a little each year due to irrigation and fertilizer inputs. The terroir of an established vineyard is different now than it was 10 years ago, and will be different 10 years from now. Chemical analysis of the soil solution will offer insights into how soil chemistry might be changed for the best.

Now climate. Climate is by far the single most important factor affecting wine quality. One has only to compare wines from California's coastal valleys with wines from the hot San Joaquin Valley to verify this truism. Exceptional wines are found in coastal areas, ordinary wines in California's hot interior valleys. The main climatic factor affecting wine quality is cool nights - mainly a large difference between day and night temperatures. Coastal breezes provide this condition but coastal mountains keep this cool air from entering California's interior valleys.

Elevation and latitude can provide some of the cooling needed to produce quality wines. Latitude should be included in climate because of its effect on day length. The latitude of California's wine-growing areas is 35º to 38º, similar to the latitudes of wine areas in Argentina, Chile, Australia and New Zealand. The latitude of wine areas in Washington and France is 45º to 48º, and it's 50º in Germany and southern Canada.

Although bud break is much later at the northern latitudes in the Northern Hemisphere, summer days are two or more hours longer which results in similar harvest dates. The influence of latitude on wine quality dovetails with a long-held belief of some in the business: Give a winemaker enough latitude and he'll come home with a gold medal.

The Match Game

Every wine variety has an optimum climate. Matching varieties with climate is the essential foundation upon which a quality wine is built. Through a process of trial and error over the years, many areas have established a reputation for producing quality wines from a given variety. The Napa Valley is known for Cabernet Sauvignon; the Salinas Valley for Reislings; Paso Robles for Syrah; Oregon for Pinot Noir and the Marlborough area of New Zealand for Sauvignon Blanc. The best vineyard manager or wine maker in the world can't overcome the handicap of planting a variety in the wrong location for that variety.

Although climate is the major factor influencing wine quality, there are two other important inputs that were alluded to above. Vineyard management and winemaking skills are each far more important than soil quality. Both vineyard management and wine making are as much art as science and there are a number of excellent, skilled individuals in each discipline scattered throughout the world. In the United States, many are graduates of the UC Davis department of viticulture and enology and, more recently, graduates of Fresno State are contributing to these disciplines.

The best vineyard managers are those that are "at one" with the vineyard and spend time in the vineyard "listening" to the vines. They manipulate sunlight, first by planting on north, south, east or west slopes, then by planting north-south or east-west rows. They manipulate vine spacing, both in-row and between rows, trellis height. pruning and leaf pulling. They manipulate vine vigor, a major influence on wine quality, by manipulating water and fertilizer inputs. These manipulations have far more influence on wine quality than does soil. Similarly, winemakers produce quality wines by judicious timing of harvest dates, by blending wines from different vineyards and by closely monitoring storage conditions. There are some vineyard managers that double as winemakers; the best are akin to symphony conductors.

The emphasis on terroir puts a premium on promotional skills; on ad or label copy that can convince a naive buyer that he's about to purchase the best wine that money can buy. The dusty farm town of Lamont is located a few miles from Bakersfield in the southern San Joaquin Valley. Take a person with a modicum of writing skills and lock him in a room with a suitable supply of pharmaceuticals (and instructions not to use the word "subtle" more than once) and he will emerge with a love poem of Lamont's terroir that could make one tremble in anticipation. True story: Twenty-five years ago, Mt. Lamont wine was produced in Lamont and many cases were sold to well-heeled buyers back east.

Terroir is a bogus term and has been bogus from the get-go. The term should be retired forthwith, although doing so would be painful to confirmed terroirists. Just like pulling a tooth once it has abscessed, it should be removed for the long-term health of the patient. French terms have a certain cachet and the term terroir carries a veneer of erudition that can be difficult to discard. What is needed is a new term, one that encompasses and emphasizes the three main components of wine quality: climate, vineyard management and wine-making management. Manage a trois would be inappropriate. Manage da vino? We'll work on it.

Joe Traynor is a certified professional soil scientist, crop scientist and agronomist listed with the American Registry of Certified Professionals in Agronomy, Crops and Soils, Ltd. He holds multiple degrees from the University of California, Davis, is a member of the American Society for Horticultural Science, and is the author of Ideas in Soil and Plant Nutrition, published by Kovak Books.