Issue link: https://read.dmtmag.com/i/764739
w w w. v w m m e d i a . c o m J a n - F e b 2 017 | V I N E YA R D & W I N E RY M A N A G E M E N T 2 9 influence the character of wine: variety, bedrock geology, climate, soil hydrology, physiography (orien- tation, slope, elevation), soil biota, vineyard management techniques and winemaking. While climate holds the upper hand, Burns cites the physical characteristics of soil, including its water-holding capacity, as being just as important as its chemical characteristics in terms of produc- ing distinctive terroirs. "The tex- ture and structure of soil affects its drainage characteristics," says Burns, who points out that high- potential sites are often on dark- colored igneous rock, unweathered shales, sandstones and limestones with the addition of metamorphic rocks and alluvium. He describes an ideal site as being well aggregated and well drained with some fine particles for holding water, no plant-avail- able aluminum or salts and having some organic matter in the upper layers. "Because soil characteris- tics affect grapevine growth and phenology, they primarily influ - ence flavor development through affecting the timing of the ripening period." Trought and Pogue both address the concept of scale as a key factor. "The interpretation of the terroir response on a 2 ha vineyard is very different compared to an entire region. Even within a vineyard, marked differences in fruit compo- sition can be recognized in adjacent vines — each vine is in its own ter- roir, says Trought. For Pogue, who writes AVA peti- tions, terroir is expressed in single- vineyard wines. "In defining how an area is different, once you get beyond the scale of about 40 acres, you're generally beyond the scale of terroir," he says. "Large AOPs and AVAs are really a collection of terroirs used for the purpose of marketing wines." THE HUNT FOR TYPICITY "The expression of terroir [in wine] is the easiest thing to destroy and the hardest thing to capture," says Pogue. "Winemakers have all of these tools they can use to force style." According to Burns, the best expression of terroir can be found in cool climate grapes — thin-skinned reds like Pinot Noir and whites like Riesling and even Chardonnay. "Variety can overpow- er terroir," he says, citing Bordeaux varieties that express similarly in different soils. "Terroir is expressed more clearly in cool climates. When we hold other factors the same, we can taste the differences in the three parent materials found in Ore- Geologist Scott Burns (on left) talks with congress attendees about Willamette Valley's geology and soil. [Photo by Maureen Battistella]