Student Combines Temperature and Sulfur Dioxide to Control Brett in Wine
Sulfur dioxide is one of the winemaker’s most familiar tools, helping control spoilage yeasts such as Brettanomyces and Zygosaccharomyces. When Brettanomyces, unaffectionately known as “Brett” among enologists, crosses a critical threshold, it imparts undesirable odors and flavors. Affected wines may have a spectrum of negative sensory qualities, ranging from sweaty horse to barnyard and worse. Zygosaccharomyces, too, has a negative impact on wine quality, as it feeds on residual sugars, introducing sediment, cloudiness and, in some instances, enough gas to explode containers.
While sulfur dioxide can prevent these some of these problems, some individuals are sensitive to the chemical. Additionally, the wine industry has been striving to reduce the use of sulfur dioxide due to growing consumer interest in foods and beverages with fewer additives. In response to this growing consumer demand, scientists at WSU and elsewhere are investigating the use of antimicrobial schemes that reduce reliance on sulfur dioxide by combining its use with other, non-chemical treatments. Jesse Zuehlke, a Ph.D. student in the Washington State University/University of Idaho School of Food Sciences, has pushed the science forward by investigating the interactive impact of temperature and sulfur dioxide concentration.
Zuehlke, mentored by food science professor Charles Edwards, cooled identical wine samples to four different temperatures between 10 degrees Celsius (50 degrees Fahrenheit) and 22 C (71.6 F). He introduced Brettanomyces bruxellensis and, after an acclimation period, added varying amounts of sulfur dioxide. Preliminary data showed that the combination of temperature reduction and sulfur dioxide addition had a greater effect than either treatment independently. Zuehlke identified a sweet spot where the combo treatment had the greatest efficacy. With temperatures of 15 C (59 F) and below, a molecular sulfur dioxide concentration of 0.25 mg/L was sufficient to control the three strains of Brett that he tested in the laboratory, preventing the emergence of undesirable aromas and flavors.
This SO2 concentration is significantly below the 0.4-0.6 mg/L of sulfur dioxide often recommended for aging wine under commercial conditions.
Beyond his lab work with wine and yeasts, Zuehlke’s accomplishments include a first-place team award at the 2012 “Developing Solutions for Developing Countries” national competition. Zuehlke served as captain of the student team that created “Mango Maandazi,” a fried bread product incorporating mangos to address harvest and nutrition issues in Kenya. For more information on the Mango Maandazi project, see http://bit.ly/KHX8h4.
As Zuehlke completes his research and anticipates graduation in May, he is looking forward to a career in food product development.
For more information on the work in Edwards lab, see http://bit.ly/Sj5bU2.
Latest Issue of VEEN Offers Tips on Dealing with Smoke Taint and More, and a Glimpse of Robots to Come
The new issue of WSU’s Viticulture and Extension Newsletter (VEEN) is out and, as usual, is chock full of valuable information for professional practitioners and passionate amateurs.
On the enology front, doctoral student and phenolic wizard Federico Casassa continues his series on maceration and red winemaking, this time focusing on aromas. Casassa points out that human taste buds are pretty basic, perceptually speaking, while our noses are much more discriminating, capable of perceiving about 10,000 different odors.
Jim Harberston, WSU’s resident expert on wine chemistry and the winemaking process, offers a timely note on smoke taint. Smoke taint can result in wine with some unpleasant taste and aromas, and he offers some relatively simple ways of dealing with the potential problem.
Thomas Henick-Kling, director of WSU’s viticulture and enology program, weighs in with a short piece on atypical aging in white wines, a flavor defect that can arise when vines experience water stress. He offers a quick test to determine if your wine is likely to develop ATA.
On the viticulture side, state Extension viticulturist, Michelle Moyer, and entomologist David James present the results of a study on using dormant lime sulfur in Washington vineyards.
Master’s student Matt Halldorson presents a summary of two years of data from a study he conducted on the impact of drought and cold tolerance in Grapevine Leafroll Virus-infected plants.
Vision Robotic’s Tony Koselka writes about preliminary results from a prototype robotic grapevine pruner. The robotic pruner is guided by software algorithms that tell it where to cut, and it “sees” the plant with 3D camera imaging technology. Want one of these gadgets for your very own? “Vision Robotics is focused on creating technology to enable robots to autonomously and intelligently work in real world applications. The company has developed an extensive library of software, hardware and technology useful for the automation of many tasks. Depending on funding levels, the pruner could be in commercial production in as little as 18 months.”
Download your (free, as ever) copy of VEEN at http://bit.ly/veenf2012.
Airfield Estates’ legacy of 45 years continues to soar on site of WWII airbase
Step through the doors of the Airfield Estates’ tasting room in Prosser, and you step back in time to the 1940s. Swing-era jazz filters in from hidden speakers while wall space is dedicated to photos of World War II military planes. One photo, dated 1942, shows a line of planes in front of a 70-foot water tower, hangars, barracks, and a weathered mess hall. Airfield Estates owner and WSU alum Mike Miller grew up in that mess hall.
Miller is full of stories about the former airbase that gave the family wine business its name. But equally important to him is the history of four generations of Millers who farmed around Prosser and the family’s Cougar tradition.
Bringing Water to the Valley
Miller points to a black-and-white photo of his grandfather, Howard Lloyd Miller, taken in 1938. In it, the elder Miller stands in front of a canal tunnel near Ellensburg Canyon, just before the new Roza Irrigation District started delivering water to the Yakima Valley. Today, the district provides irrigation water to 72,000 acres.
Lloyd, as his family knew him, was the first Miller to own and manage farmland in Sunnyside at the turn of the century. He was a visionary, seeing the promise of agricultural wealth in the Yakima Valley. He worked tirelessly to bring a second irrigation canal to the lands northeast of the Yakima River.
It was also because of Lloyd that an airbase came to be on Miller land. In 1941, Olympia Air Transport Company leased non-farming land from Lloyd to build the airbase as a training ground for military pilots. After the war ended and the base shut down, the site and buildings reverted back to Lloyd, who converted them for use in agricultural production.
Lloyd named the farm Airport Ranch, and at first raised livestock, alfalfa, and grains. Later he shifted to producing sugar beets, corn, asparagus, beans, and mint.
“These unique buildings became the headquarters of the Miller family’s farming operations up to today,” Miller said. “Over time, many of the buildings began to deteriorate, but two of the original hangars still exist, and we continue to use them as workshop and storage facilities.”
WSU and Wine
WSU history for the Millers started even before farming. Miller’s uncle, Howard, was the first in the family to attend and graduate from Washington State College in the early 1930s. Miller’s father, Don, attended WSC for two years but left as a junior to join the Army Air Corps during WWII. After the war, Don returned to Sunnyside and joined the Airport Ranch operation until he retired in 1990.
Miller followed in his father’s footsteps and joined the U.S. Navy in 1967. After his discharge, he attended WSU, graduating with an agronomy degree in 1974.
While Miller was in the military and at WSU, Don began planting wine grapes at Airport Ranch. In 1968, inspired by WSU horticulturist and “Father of Washington Wine,” Walter Clore, Don started with an experimental vineyard of Pinot Noir, Cabernet Sauvignon, Chardonnay, and Riesling. By 1971, he took the plunge and planted 10 acres of commercial wine grapes, selling the first yields in Canadian markets.
Two events marked Airport Ranch’s full immersion into the Washington wine industry. In 1977, the U and I Sugar Company announced it would close all Washington sugar production plants, thereby eliminating the farm’s primary market for its sugar beets. At the same time, Chateau Ste. Michelle, Washington’s biggest winery, wanted wine grapes from outside producers to meet demand.
“The technical support that we received from Chateau Ste. Michelle was invaluable in our education as growers,” Miller said. “Today, we are still heavily involved with the company.”
In 2007, after three decades of supplying grapes to the state’s largest wineries, Miller decided it was time to fly solo. The fourth generation of Millers–son Marcus, head winemaker, and daughter Lori Stevens, marketing director–had joined the family business, each gaining experience in winemaking and wine marketing locally as well as in New Zealand and Australia. Airfield Estates began offering its own estate wines in the spring of that year and held a grand opening of its Prosser tasting room in July.
“And that’s been pretty much the end of Cougar football for me,” Miller joked. But not the end of expanding his Cougar family. Lori’s husband, Aaron Stevens, an enologist for Chateau St. Michelle in Paterson was raised a Cougar, thanks to his father, Jim, and grandfather, Blair, both WSU alums.
In the last five years, Airfield Estates has increased production from 2,300 cases to 30,000 cases, some under its Lone Birch label. In addition, Miller opened another tasting room in Woodinville, Washington, in April 2010. The Airfield Estates’ barrel room, with a storage capacity of 600 barrels, is full, Miller said. Plans are in the works to build a second storage facility in a year.
Visitors to Airfield Estates winery office in Prosser can certainly enjoy the premium wines, but the myriad reminders of the family’s ties to aviation are equally appealing. A huge water tower with the word “Airfield” can’t be missed from Interstate 82.
“The tower is a two-thirds-scale model of the original at 45 feet, per Prosser regulations,” Miller said with a smile.
For more information about Airfield Estates, visit http://www.airfieldwines.com/. If you have a Cougar connection and want your winery or vineyard operation featured in WSU’s Voice of the Vine, we’d love to hear from you! Contact the editor at email@example.com.
Wine Science Center at WSU Tri-Cities
Deep in the heart of Washington wine country, the Wine Science Center at WSU Tri-Cities is well on its way to becoming a reality, thanks to WSU’s many public and private partners. When completed, the center will be a world-class research and teaching facility designed and equiped to meet the needs of the Pacific Northwest wine industry. With more than $14.1 million raised towards the project funding goal of $23.25 million, groundbreaking is on track for Sept. 2013. Learn more, and stay current, with what’s going on with the Wine Science Center by subscribing to the Updates newsletter at http://bit.ly/RYbpwy.