PSU Magazine Fall 2003

W hen Professor Scott Burns swirls and sips a glass of Pinot Noir, he experiences all the essentials: the bou– quet, the fruit , the finish, and the dirt. The dirt? Well, after all, he is a geologist. And as such he has become an expen on the effects and importance of soils in the growing of premium wine grapes. Great soil, along with other environmental factors such as climate, can account for 80 percent or more of the quality of a wine, says Burns, who got this statistic from Dick Erath, one of Oregon's pre– mier winemakers. Fonunately for us in the Pacific Northwest, Oregon's Willamette Valley has some of the best grape-growing soil on the planet. Burns, who lives just outside Wilsonville in an area he says is great for wine grapes, started making wine 30 years ago, and says he dreams of own– ing a winery some day He has shared his expertise with the public during annual PSU Weekend lectures, and this year he's going to give his presentation as part of a tour of local wineries. T hese local wineries, dotting the northern Willamette Valley, are strategically located on hillsides that began developing as potential grape growing land nearly a million years ago. They are volcanic and marine sedi– ment soils that were laid down over the course of eons. They are old, rich with clay, and relatively poor in nutrients– not what you would immediately think of as having agricultural potential. Most of Western Oregon's great crop growing land is elsewhere, developed between 12 ,000 and 15,000 years ago when the area was inundated with water from the great Missoula Flood. The flood covered the valley floors with rich silt that has made Oregon the incredibly abundant agricultural mecca that it is. But not for wine grapes. Burns explains that grape vines grown in the rich soil of the valley bot– toms will produce thick leafy plants, relegating the grapes to a kind of underling status. To produce good wine, you have to go up into the hills onto the old soil that existed before the flood. There, on the weathered, high-day, nutrient-poor soils of places such as the Dundee Hills, the vines have to struggle a bit. And in struggling, they put their best energies into the one part of the plant that will assure the survival of the species: the grape. Dionne Starr-Peace, one of Burns' graduate students, began logging soil classifications of the different Northern Willamette Valley wineries several years ago. She and Burns surveyed 28 winer– ies growing grapes on 45 locations and found that all but 9 percent come from two deeply weathered red soils: the Jory series, which is formed on vol– canic rock, and the Willakenzie series, formed on marine sediments. Both soils are between a half-million and a mil– lion years old. With time, soils become redder and more day-rich, which is exactly what these soils are, Burns says. 0 regon caught the wine world by surprise in 1975 when the Eyrie Vineyards won an international com– petition with a Pinot Noir made from grapes grown on Jory soil. The state has been considered an excellent Pinot-growing region ever since and has been compared with some of the best viticulture areas of France. Other entrepreneurs began planting wine grapes on Jory soil in an effort to copy Eyrie's success. Then growers started looking at other soils with simi– lar characteristics. How about marine sediments7 Some growers took the plunge and voila! Wines from Willakenzie soils began to make a name for themselves. Burns says he can tell the difference. "For me, Jory wines come on with an incredibly good bouquet, but not a great finish. Willakenzie wines maybe don't have a great bouquet, but they have a smooth, nice finish, " he says. Naturally, soil types are a source of debate among wine makers, especially those whose vineyards are on different soil types. Soil mapping of the area is being updated , which will produce subclassifications of Willakenzie soil. Soon, winemakers will be able to tell their customers that their wine comes from not just the Willakenzie, but a specific corner of the Willakenzie with its own unique attributes. David Adelsheim'66, co-founder of Adelsheim Vineyard in Newberg, has used grapes from many different sites and several different soils. He said there are often differences between wines produced from sedimentary soils and those from basaltic soils, but its not clear what causes them. "1 can often taste the difference. But it's not as black and white as some would like it to be," he says. "Theres a general feeling that basaltic soils, if properly tended, result in wines that have more red fruit CTa– vors (such as strawberry, red raspberry and maybe red plum), and sedimentary soils produce wines with more black fruit CTavors (black cherry, blackberry, black currant and perhaps black plum). But plenty of people would disagree." John Platt, who owns Helvetia Vine– yards and Helvetia Winery with his wife, PSU faculty member Elizabeth Furse, says soil makes a big difference in the taste of his wine. He grows his grapes on Cascade soil, a clay earth flecked with iron. He says it took seven years for the vine roots to make their way down through the top soil to the heavy clay underneath , and only then did they produce a crop that he and his wife were happy with. ''l've had people say they notice a distinct cherry flavor coming from the iron," he says. These distinctions, which occur when the vines roots become deeper and broader and are exposed to more of the bedrock soils underneath , con– tribute to the attributes that set winer– ies apart from one another-and make wine touring so enjoyable. B ut the soil has a practical side as well. Alex Sokol Blosser '97, MBA '03, vice president of Sokol Blosser Winery in Dundee, said one of the best attributes of clay soils is the fact that they hold water and slowly release it over time. Irrigation is a con– troversial subject among winemakers, he says, and most of Sokol Blossers vineyards are not irrigated due to the characteristics of the clay soil. Sedimentary soils, such as the Willakenzie, have less clay than soils of basaltic origin and are more prone to drought stress, says Adelsheim. He will no longer plant white wine grapes on FALL 2003 PSU MAGAZINE 7