On wine: Importance of terroir still unsettled

As a concept, terroir raises controversy among winemakers and grape growers around the world. There are exceptions, of course, but most European winemakers claim that terroir has a direct impact on wine quality, while winemakers in California, Australia and other new world wine regions believe that wine quality is more the result of other factors than just terroir.

The Oxford Companion to Wine defines terroir as “the total natural environment of any viticulture site.” That definition is as good as any, but the concept is more complex and layered.

Terroir takes its name from “terra,” the Latin word for earth. But the concept is uniquely French . So strong is the belief in the power of terroir that in 1937, the French government determined that terroir would define the set of regulations known as Appellation d’Origine Controlee, which control French grape growing and wine making.

The value the French place in soil was illustrated in the recent purchase of Villa Sorriso, the Mayacamas Mountains estate of the late actor Robin Williams, by the owners of Chateau Pontet-Canet, a fifth-growth Bordeaux. “The soils here correspond perfectly to the style of wine that we hope to make,” Jean-Michel Comme, the chateaux technical director, told Decanter.com.

For the California wine consumer, however, the concept of terroir is more abstract. Some see terroir as nothing more than wine mumbo-jumbo, while others maintain that understanding the total growing environment of a wine grape can add greatly to wine quality and enjoyment. Kimberlee Nicholls, winemaker for Markham Vineyards in the Napa Valley, appreciates the impact terroir has on her cabernet sauvignons.

“I love making cabernet that expresses terroir,” she said. “The volcanic loamy soils in our Calistoga vineyard produce more delicate red-berry fruit with hints of fennel, while the sedimentary gravel soils of our Yountville Vineyard give cabernet sauvignon a more chocolate character.”

Soil is one of three main components that make up the over-arching concept of terroir, the others being topography and climate. There are dozens of soil types scattered throughout the wine regions of the world. A few years back, scientists told me that in the Napa Valley alone there are 33 different soil series and more than 100 soil variations. That new knowledge about soil encouraged me to look further at the impact of terroir on wine quality.

Topography describes the features of a vineyard site and its interaction with local climate, usually referred to as the mesoclimate. The elements that influence topography include the elevation of a vineyard site and its proximity to a major body of water such as an ocean, lake or river.

Locally, those elements can be found in the Sonoma Coast appellation facing the Pacific Ocean, the Russian River and the Mayacamas Mountains ridge that separates Sonoma and Napa counties.

But while soil and topography are vital, many terroirists say that climate is the most important element. A vineyard is influenced first by regional macroclimate, then the vineyard site’s mesoclimate and finally the microclimate between the rows of vines.

“I think that climate is bigger than soil,” said Pat Henderson, winemaker for Kenwood Vineyards in Sonoma Valley, citing Jack London Ranch in Glen Ellen, which sits at 700 feet above the valley floor.

“The Jack London Ranch is a unique terroir, high elevation, above the fog and with oblique sun in the afternoon when it’s the hottest part of the day. Terroir is a holistic concept and the most important aspect for wine quality, since you need good terroir for good grapes.”

Until science became involved in viticulture, there was little understanding of the components of terroir and how it affects wine quality. That lack of understanding was the wedge that kept the gap open between Old World and New World acceptance of the concept of terroir.

Further, prior to California’s wine boom of the 1970s, growers planted varieties regardless of local climatic conditions, and growers and winemakers didn’t communicate on the same level they do today. The communication gap was even more serious between the vintner and the grape grower and winemaker.

Such was the case of Bill Jekel, owner of Jekel Vineyard in Monterey County. He was an advocate of Monterey County wine grapes, particularly the area known as Arroyo Seco in the Salinas Valley, where Jekel had two vineyards. He is quoted as saying this about the importance of soil and terroir in a 1983 interview for the wine magazine Decanter: “Soil components, themselves, do not contribute identifiable flavors to the earth.” The words resonated throughout the wine world and were picked up by Bruno Prats, then owner of Cos d’Estournel in St. Estephe, Bordeaux. Prats responded, saying that gout de terroir “encompasses sun, slope climate and exposure to the elements.”

The argument raged in the international wine press until Jekel came to fully understand the meaning and value of terroir. But, still unsure about the soil’s role in wine, he conducted a test.

Jekel’s winemaker put chardonnay in 10 glass carboys, then added a small amount of soil from 10 vineyards, including Napa Valley’s Martha’s Vineyard, known for the eucalypt character it imparts to a wine. The scant results, that each sample had a different taste, were persuasive.

The conclusion, at least for people who include Dennis Martin, retired vice president winemaker for Fetzer Vineyards in Mendocino County, is that terroir is site specific or, at the most, a factor of mesoclimate.

“I think we are speaking about the best sites in the very best appellations,” he said, citing as a prime example the Bien Nacido Vineyards in the Santa Maria Valley, from which he has been sourcing pinot noir for 25 years.

But Martin believes that being able to put your finger on the influence of terroir in a wine is not easy, due to the influence of other factors.

“I do believe in terroir, the caveat being that what we do in the winery and winemaking interferes with the true expression of terroir.”

For the wine consumer, then, the bottom line is that there is no bottom line. More and more grape growers and winemakers are becoming terroir believers, but there are still skeptics. Today, there are more wines in the marketplace that are expressive of the region or vineyard, and that is good news for the wine consumer.

Gerald D. Boyd is a Santa Rosa-based food and wine writer.