Chateauneuf de Pape's unique rock terroir
Terroir is a French word that has no translation in English. Terroir is much more than a word----many believe it’s a concept at the very heart of wine-making. Terroir is the sum of the total effects that the local environment has on making a wine unique: for example, soil, climate, topography, drainage. Even the pests in the vineyard are considered part of the terroir.
Conversely, there are some who think the whole idea of terroir is a marketing ploy by the French to say that no other country in the world can produce wines that measure up to those in France. Researchers at U.C. Davis, however, may have just unlocked the door to scientifically understanding terroir. Furthermore, they may have actually found a way to measure terroir through DNA testing of microbes of grapes.
Microbes grow on surfaces of all wine grapes. These bacteria and yeasts can be friendly or unfriendly. The friendly ones can be helpful to jump-start fermentation and can also powerfully effect the flavor of a wine. The unfavorable ones can spoil it. Scientists in the above study tested microbes associated with Chardonnay grapes from three different districts of California: Napa, Sonoma and the San Joaquin Valley. They found in each area a set of microbes unlike the microbes found in the other two valleys. These researchers next conducted testing on Cabernet Sauvignon grapes from the same three districts. They noticed again a unique set of microbial communities in each of the districts.
How exactly these region-specific microbes contribute to regional variation of a wine involves taking the scientific evidence to the next step of proving how terroir actually gets into a bottle of wine. For more on this fascinating investigation, check out the recent article in the New York Times: http://www.nytimes.com/2013/11/26/science/microbes-may-explain-some-of-the-mysteries-of-terroir-and-wine.html?ref=todayspaper&_r=0