LAKE TAHOE— In certain social circles, there arguably is no more effective way to be labeled a pretentious bombast than to take a slow sip of wine and utter something like:

“I detect a rich flavor of blackberry with a succinct woody finish and perhaps a fading hint of citrus.”

However, in other social circles, there is no better way to ingratiate oneself.

Irrespective of the socio-economic connotations associated with being a wine connoisseur or whether the vernacular surrounding wine tasting strikes one as helpfully descriptive or snootily overblown, winemaking is dynamic and complex, and those with a sophisticated knowledge of the process say every decision made by a viticulturist — a term for one who cultivates grape vines — will be apparent in the final product.

‘Taste of the earth' The word “terroir,” or “gout de terroir,” is defined by the Oxford Dictionary as the characteristic taste and flavor imparted to wine by the environment in which it is produced. Gout de terroir translates literally from French to English as “taste of the earth.” The world is in vogue with food fashionistas who use it to describe the regional flavors of wine and other products. Stephen Tebb is an ardent adherent to the concept of terroir — or that one can detect the origin of a wine in its flavors — but believes the use of the word is over saturated and overuse has detracted from the original meaning.

The geography of taste

Stephen Tebb, winemaker at Napa Valley-based Robert Craig Winery, gave a recent talk at University of California, Davis Tahoe Environmental Research Center, relating to how agricultural and biochemical scientific practices are informing the winemaking industry.

Tebb specifically discussed how his degree in oenology (science of wine) from UC Davis informs his daily operations at the vineyard; yet, he avoided overly scientific information regarding biochemical interactions, instead providing a more accessible version of winemaking that played well to a very attentive — if not slightly buzzed — crowd.

Perhaps the most crucial decision a winemaker can make, Tebb said, is where to place his or her vineyard — climate, precipitation, slope or gradient of the land, soil type, acidity of soil, amount of sunlight and wind vectors are the prominent factors.

“Wine should reflect some aspect of its origin,” Tebb said. “It denotes the special characteristics that the geography, geology and climate of a certain place bestows upon the varieties.”

Most individuals with barely a passing knowledge of wine can distinguish among different grape varieties, such as Merlot, Cabernet Sauvignon or Chardonnay. But Tebb's claim is that wine varieties as distinct and different as red zinfandel and Chardonnay share a common thread of taste if they are grown in the same region.

Conversely, if one takes identical grapes and plants them in two different regions — say the Loire Valley in France and Napa Valley — one will end up with very different tasting products.

“Each grape exhibits a unique quality that is specific to that region,” Tebb said.

Creative decisions

However, it's not a matter of simply choosing an ideal plot of land in largely heralded winemaking regions like Napa, Sonoma or the emerging Paso Robles region and letting the vines run rampant until harvest time.

The winemaker or viticulturist is responsible for making creative decisions in an effort to reach “the best expression of the region,” Tebb said.

For instance, Robert Craig's Chardonnay is grown in Durrell Vineyard, located in Sonoma Valley close to the San Francisco Bay. Tebb said the natural acidity of the soil and cool fog-laden air make for ideal growing conditions for the white wine.

However, Tebb believes aging a majority of the wine in stainless steel barrels as opposed to classic oak barrels highlights and draws out the taste of this particular wine more effectively — an example of how the winemaker's intuition helps craft the final product.

The decision to employ stainless steel is specific to that type of Chardonnay, Tebb said, as Robert Craig also produces a Cabernet Sauvignon in the Spring Mountain District of Napa Valley that is aged for 20 months in Chateau-style French oak barrels.

Tebb said he must make a litany of those types of decisions based on the type of grape, the region where it's growing and the best possible expression of those combining factors in order to create a great wine.

Thus, winemaking, when viewed holistically, is less of a science and more of an art, with an individual operating creatively within certain generally accepted formal guidelines to realize an original expression reminiscent of a specific time and place.

Nevertheless, science heavily informs this particular art form, Tebb said.

Science providing tools

Scientific data can help a viticulturist from the beginning of the winemaking process, until the end.

Tebb employs the use of aerial infrared photography that paints a picture of how much heat is in certain portions of the vineyard, which indicates the presence of rocky soil and can help form planting decisions.

Soil analysis, particularly regarding salinity, acidity and plant nutrient status, help drive fertilization decisions, Tebb said.

Many scientific measurements are taken throughout the growing season, as soil moisture content, the vines' water potential for leaves, sap flow in vines, sugar and acid in the grape help guide choices regarding the ideal time to harvest, Tebb said.

Such measurements are also critical to the fermentation process, when yeast interacts with the sugars in the grape (a grape consisting of 24 percent sugar will create a wine that is 14 percent alcohol) to create ethanol or ethyl alcohol.

Tebb must consistently monitor the amount of sugar, oxygen and yeast in the process. Controlled and steady temperatures are also critical to a successful transformation of grape juice to wine.

At the biochemical level, the biomolecule tannin — the modification of which plays a crucial role in the aging of wine and is responsible for its astringent flavor — is thoroughly analyzed and tinkered with during fermentation.

Technological developments have also helped refine the winemaking process.

In the past, Tebb told the crowd, once grapes are harvested, workers meticulously choose the best ones and discard those that are damaged or failed to ripen.

Manufacturers have developed an optical sorting machine, which, once given a digital image of an ideal grape, can sift through a conveyor belt full of fruit, dispensing rotten or damaged grapes with a brief but strong gust of air.

One year, after harvest, meteorological forces meant Tebb's crew had to accelerate the sorting process in order to prevent fruit rot.

“Our entire harvest would've gone bad if it wasn't for that machine,” he said. “It saved us about five to 10 days.”

Never the same

While making wine is essentially the same as it was 10,000 years ago — archeological evidence suggests the earliest known winemaking operation was located in the Eastern European country of Georgia circa 8,000 B.C. — today's viticulturists have a greater arsenal of tools and sophisticated measurement techniques at their disposal.

Tebb said he believes this makes for more consistency in the winemaking process, meaning a reduction of error year to year.

Nevertheless, the dynamic forces of climate, topography and geology all interact differently from year to year, he said, meaning a vineyard will never replicate the exact same wine.

“It's all part of the fun,” he said.