Kerry Shiels' parents, Hugh and Kathy Shiels, planted the DuBrul Vineyard, their Yakima Valley property in Washington, in 1992. That same year, Kerry, then 13, made her first wine. "It was a science project," explains Shiels, now 34. "That's what you do when you grow up in wine country." Onetime farmers of alfalfa, asparagus and Concord grapes, the Shielses knew they'd come across a good spot for Vitis vinifera with the DuBrul site. The vineyard's 45 acres of basalt promontory peak at around 1,300 feet of elevation and hold diverse microclimates. Its singular geologic conditions distinguished it early on as a premium site for winegrowing, and it was among the first sources of vineyard-designated wine in the state.
A career in mechanical engineering detoured Shiels from the family business at first, but in 2009, she became winemaker for their estate label, Côte Bonneville, where she oversees the production of Cabernet, Riesling, Syrah and more. Shiels spoke with assistant editor Esther Mobley about the advantages of Yakima's climate, her interest in viticultural research and Washington's lack of phylloxera.
Wine Spectator: How did your career as an engineer lead you to winemaking?
Kerry Shiels: I got hired by Fiat [to design cars] right out of college. But eventually I had been promoted to the point where I was making Excel spreadsheets and going to meetings, and that's not what I wanted to do long-term. I like to actually make stuff. You can't really go home at the end of the day and relax with a tractor. Winemaking takes all the things I liked about my engineering career and gets rid of the meetings and the commuting—though there are still some Excel spreadsheets.
WS: Did the University of California at Davis master's program prepare you for the challenges of winemaking in Washington?
KS: Yes and no. The conditions of winemaking in Davis are very different from Washington. That said, the climate up here in Washington is wonderful. Because we have warm days and cool nights, we get ripe fruit but we also retain acidity. Because we have long growing days, if you manage your canopy appropriately, you don't have to worry about [needing] extra hang-time to get rid of green flavors, because the sunlight reduces the methoxypyrazines in the vineyard. So we can pick earlier, we can pick for reasonable alcohols, for ripe fruit without the superjammy fruit flavors—we get balance. California's warm, so you get lots of fruit flavors. Oregon's pretty cool, so you get complexity and structure. Washington's in the middle, so you get both. And because it's a desert and we can control vine vigor with irrigation, we have more control than so many regions in the world.
WS: For years, you've volunteered your wines and your vines for research projects with the Washington State University Irrigated Agriculture Research and Extension Center. What have you learned from this research?
KS: A lot of the things that we do in the vineyards have come out of collaborations with WSU. We've done a lot of work on irrigation, which has been great: It helps us reduce the amount of water we use, to manage water more sustainably, increasing our quality at the same time. We've done work on integrated pest management, planting host plants for beneficial insects all over the vineyard. We've found how to get the optimal sunlight and temperature environment on each cluster [through canopy management]. We're a very research-friendly state.
WS: How does the fact that your vines are own-rooted affect the winegrowing process?
KS: Depending on the rootstock that you use, you can completely change the way the vines grow. That can be an advantage, [but] if you choose the wrong rootstock, you're at a huge disadvantage. But ultimately, the sense of terroir that you get on vines' own roots is unique anywhere in the world.
The interesting thing is that phylloxera [exists] in Washington, but it's primarily in the Concord vineyards—it doesn't thrive where the wine grapes are planted. My theory is that in the lower areas of Yakima, where Concords are planted, there's more soil; when you get up on the hillsides where vinifera is planted, there are poor soils with less water-holding capacity. The conditions are less favorable to phylloxera. As winemaking moves into other parts of the state, where the climate's very different, phylloxera might become more of a problem. We don't know yet—time will tell.
WS: What allows you to grow such disparate grape varieties in such close proximity to one another?
KS: DuBrul is a rocky basalt promontory, so we have a lot of different microclimates within our 45 acres. We've planted Cabernet on the steepest part of the south-facing slope. On a more gentle slope, we have Merlot. On the west-facing slope, Chardonnay. With irrigation, we can direct water to whites so we can have more canopy development, whereas for the reds we get a little less vigor. Red grapes like more sunshine; white grapes need more canopy so they don't get sunburned.
WS: What is distinctive about DuBrul Vineyard fruit?
KS: The Cabernet and Merlot have this intense cherry [flavor]. It's not quite Bing cherry, not quite red cherry; it's a very distinctive element, combined with soft tannins present in quantities capable of producing long-lived wines [that are] also approachable young.