Read the original story in Oregon Wine Press here.
A sixth-generation Oregonian, Scott Burns is a professor of Geology and Chair of the Geology Department at Portland State University.
He earned his Bachelor of Science in chemistry from Stanford University in 1969; his masters in physical science from Stanford in 1970; and his doctorate in geology from the University of Colorado in 1980.
Burns has been teaching at the university level for 39 years and has taught in Switzerland, New Zealand, Washington, Colorado and Louisiana before returning to his native Oregon 19 years ago when he started at Portland State.
His specialties include natural history, geological hazards, the Missoula Floods, terroir, Quaternary geology, geomorphology, engineering Geology, heavy metals in soils and environmental geology.
He’s currently working on a book on the Missoula Floods. Burns lives in Tualatin with Glenda, his wife of 34 years; he has three children, Lisa, Doug and Tracy.
When and how did you become interested in soil?
SB: I fell in love with soils when I was working on my Ph.D. in 1976. The study of soils has been the center of all of my research since that time, whether it is terroir, high mountain soils, radon, heavy metals and trace elements in the soil (like arsenic), landslides, earthquakes, etc. I love getting into a soil pit and reading the story that is there! Soils are a key to unlocking the surficial history of any place on the face of the earth.
What interesting discoveries have you uncovered in your research on terroir and wine?
SB: Soil is one of the seven factors (as I see it) that leads to differences in wine. The first five are what the French call terroir: the grape type, the climate, the geology/soil, the physiography (elevation and slope direction) and the soil hydrology (water holding capacity). Soil is a very important factor. It imparts 13 of the 16 essential nutrients needed by the vines to make grapes (the others are oxygen, hydrogen and carbon which come from the air and water). The other two main factors that are very important but don’t involve terroir are the winemaker and vineyard management.
What I have learned is that soil can really impart different flavors to the wine. In the Willamette Valley, the same winemaker keeping all of the seven above factors constant in the same year can produce three different Pinot Noir wines if they use three different soils. The three main soils in the northern Willamette Valley, the Jory, the Willakenzie and the Laurelwood, produce completely different wines.
Which soils are best suited to grow Old Word-style Pinot Noir vs. big reds like Cab Sauvignon?
SB: There is no real soil that is perfectly made for Pinots vs. heavy reds. Pinot Noir grows great on the limestone soils of Burgundy and the volcanic and sedimentary soils of the Willamette Valley. The heavy reds grow well in the soils of eastern Washington (Missoula Flood sediments) and the gravelly soils of Bordeaux. It is the climate that really dictates which grape grows well there.
How much does soil affect the taste of wine as opposed to climate and elevation?
SB: We do not know how the soils affect the taste — that is what we are working on here in the Willamette Valley. I have a Ph.D. student working on this problem. When she finishes, we might know better how to answer that question. In other parts of the world, there are some relationships between the geology and tastes.
In your opinion, which Oregon wine region, or AVA, has the most interesting geological history?
SB: All of the different AVAs have great geological histories. We are working on the Columbia Gorge AVA right now. It has incredible diversity in climate and geological history and is more complex than any of the other AVAs. Each AVA is very special and has its own history that makes it unique.