Photo provided by Scott Burns
The idea of terroir was developed hundreds of years ago by French monks. It is defined as “the characteristic taste and flavor imparted to a wine by the environment in which it is produced” and “the complete natural environment in which a particular wine is produced, including factors such as the soil, topography, and climate.” Terroir includes grape variety, geology, soil hydrology and biota, physiography, vineyard management, and winemaking style. Terroir is the “taste of the place.”
Dr. Scott Burns spent his 47-year career studying the interplay of geology, climate, and soil. Wine geeks have studied the idea of terroir for years but the increased interest in drinking and making wine in America has brought it to the forefront. In 1982, only 16% of Americans reported that they drank wine. By 2012, that number had increased to 40%.
If you’ve ever picked up a bottle of French wine and wondered which grape variety it is made from, you’re not alone. French wines are named for the place where the grapes are grown, further solidifying the importance of terroir in the French winemaking tradition. In France, as in other parts of the world, the grape variety is matched to the climate. There are over 4000 varieties of vitis vinifera and they are best suited to particular climates. Gewurztraminer, Muller Thurgau, Pinot Noir, Riesling, and Sauvignon Blanc grow well in cooler climates (places like northern France, Germany, and northern Oregon/Washington) while Tempranillo, Syrah, Cabernet Sauvignon, and Merlot do well in warmer areas (think Columbia River Valley, Napa Valley, Eastern Washington/Oregon, parts of Spain and Argentina, and Bordeaux in southern France).
In addition to the right climate, grape vines need the right soil with a combination of micro- and macro nutrients, trace elements, and a pH between 5.5 and 10. Dark soil, such as reddish Jory, absorbs and retains heat that helps speed up ripening. Different soils have different flavor profiles, too. Pinot Noir, in particular, likes old, well-drained soils such as those created by glaciers (Loess), volcanos (Jory), and oceans (Willakenzie). Volcanic basalt tends to produce raspberry, plum, and currant flavors in wine while marine sedimentary soil produces the cherry flavor for which Pinot Noir is widely known.
Every state in the U.S. has a winery, but Oregon, which was recently named the No. 1 wine destination in the country by smartasset.com, has over 700 wineries; some 500 of these located in the Willamette Valley alone. Wine production represents a $2 billion per year economic impact in Oregon. The Willamette Valley is blessed with the perfect soil, elevation, and aspect to grow grapes. Our climate is similar to Burgundy, France: warm days and cool nights with at least 180 frost-free days during the growing season. Dick Erath, one of the pioneers of Pinot Noir in Oregon, said that “80% of wine quality comes from the vineyard.” The rest is up to the winemaker.
Scott Burns is a Professor Emeritus of Geology at PSU. He is a sixth generation Oregonian and member of the Beaverton Rotary Club. Thanks to Dr. Burns, the State Legislature designated Jory volcanic soil the Oregon State Soil.