Award-winning research offers choices for improving Cabernet Sauvignon
When it comes to more options for fine-tuning wines, innovative research by Washington State University and Ste. Michelle Wine Estates bridges the divide between the vineyard and the winery.
One recent research project focused on how maceration times and irrigation rates can affect the color, taste and mouthfeel of Washington State Cabernet Sauvignon wine. The study won 2014 Best Enology Paper from the American Journal of Enology and Viticulture for outstanding content and substantial contribution to the winemaking field.
“This groundbreaking experiment was a noteworthy example of industry and academic cooperation,” said James Harbertson, WSU associate professor of enology. “The Chateau Ste. Michelle vineyard team was instrumental in helping us carry out a massive three-year experiment with grapes from one of their finest vineyards. Without their cooperation and help, this work would not have been possible.”
Approximately four tons of fruit were donated annually to produce 16 wines at the WSU research winery in Prosser. Analysis of the resulting wines showed that both maceration and irrigation practices can produce desirable differences, but extended maceration has a greater effect on sensory attributes than does varying irrigation rates.
Extending maceration packs more punch
The study showed that extended maceration produces wines with less fruit-based aromas and color saturation and also enhances bitterness and astringency.
Although bitterness and astringency are desirable qualities for Cabernet Sauvignon wine, a trained tasting panel found that not all characteristics associated with extended maceration times are positive. However, undesirable characteristics can be mitigated by blending with other wines to improve their aroma, color or mouthfeel.
The researchers found that winemakers can experiment with macerating grapes anywhere from the typical 10 days to a maximum of 30. But extending maceration beyond 30 days didn’t produce enough significant differences to be worth the effort.
Regulating irrigation concentrates tannins, pigments
The study also demonstrated how regulating irrigation rates and strategically restricting water can positively impact wine’s fruity aromas and increase color saturation, astringency and bitterness.
Replacing only a portion of the water lost to evaporation creates a moisture deficit that produces smaller grapes with more concentrated color and flavor.
The most effective irrigation plan in the study replaced only 25 percent of the water lost to evaporation during the early growth stage – from when fruit appears to when it stops growing larger and starts ripening. This was followed by 100 percent water replacement from fruit ripening to harvest, which produced smaller berries without sacrificing yield.
When used wisely, regulated deficit irrigation has the added benefit of conserving water in arid areas, such as Washington’s Columbia Basin.
Federico Casassa, the lead author on the research paper, received his doctoral degree in Food Science from WSU in 2013.
“Federico and our winemaking team — Richard Larsen, Maria Mireles, and Christopher Beaver — executed this project fantastically,” Harbertson said. “However, none of it would have been possible without our viticulture colleague Markus Keller and Chateau Ste. Michelle viticulturists Russell Smithyman and Bill Riley.”
Read the full paper online (free): Casassa, L. F. et al. 2013. Sensory Impact of Extended Maceration and Regulated Deficit Irrigation on Washington State Cabernet Sauvignon Wines. Am. J. Enol. Vitic. 64:4.
– Erika Holmes
Study reveals promise for expanding hard cider industry
A new study by researchers at Washington State University shows that mechanical harvesting of cider apples can provide labor and cost savings without affecting fruit, juice or cider quality.
The study, published in the journal HortTechnology in October, is one of several focused on cider apple production in Washington state. It was conducted in response to growing demand for hard cider apples in the state and nation.
Quenching a thirst
Hard cider consumption is trending steeply upward in the region surrounding food-conscious Seattle, and Washington is part of the nation’s hard cider revival. The amount of cider produced in the state tripled between 2007 and 2012.
The rapid expansion means cider apple growers are hard pressed to keep pace with demand. Because cider apples are smaller than dessert apples – the kind we find in the grocery store for fresh eating – it takes longer to harvest them. In fact, harvest labor can account for nearly half of the annual costs of an orchard in full production.
Regions like the Skagit Valley in western Washington that don’t have large-scale commercial apple production lack experienced apple harvest crews.
“We simply don’t have a dedicated agricultural labor market in western Washington,” said horticulturalist Carol Miles, the lead author of the study. “High quality and affordable labor to hand-harvest cider apples is difficult to come by and costly.”
Miles leads one of a handful of cider apple research programs in the nation, at the WSU Northwestern Washington Research and Extension Center.
Mechanical harvest is a logical solution to the labor challenge – except for two complications. First, such a machine doesn’t exist for apples, which are generally grown in compact trellis systems, hand-picked and carefully handled to avoid bruising.
The other issue is that mechanical harvest is likely to damage fruit, but just what this means for the final product is unknown.
To address the first complication, Miles and her team used a mechanical raspberry harvesting machine to pick Brown Snout cider apples, a variety grown at the research center. The machine passes over fruit trees that are no higher than six feet, knocking the apples from trees onto a conveyer belt for collection by workers into tote bins.
Researchers assessed the level of damage to the trees and tested the fruit to see what impact, if any, bruising had on fruit and juice quality.
Olive harvester might be suitable
The two-year study showed that machine harvesting required as little as one quarter of the labor that hand harvesting required, resulting in an average cost savings of $324 per acre. Bruising did occur on all of the fruit, but it didn’t affect the quality of juice – whether the apples were processed immediately or cold-stored for two to four weeks before pressing.
Miles noted that modifications to the small fruit mechanical harvester could further improve efficiencies for apple harvest. She dreams of one day testing an olive harvester, which can pass over trees that are 10-12 feet tall – the common height for modern apple orchards.
If suitable equipment is available and affordable, then mechanical harvesting could be just what the industry needs to expand and keep up with demand for locally grown cider apples.
The paper in HortTechnology is: Yield, Labor and Fruit and Juice Quality Characteristics of Machine and Hand-harvested ‘Brown Snout’ Specialty Cider Apple. Carol A. Miles and Jaqueline King. HortTechnology October 2014 24:519-526.
– Sylvia Kantor
Blended Learning student-made wines perfect for holidays
Purchasing a bottle of Washington State University Blended Learning wine provides a taste of what today’s top-notch WSU wine science students are producing.
Viticulture and enology students recently released their second series of wines: a 2012 Syrah from vineyards in Walla Walla and Horse Heaven Hills and a 2013 Yakima Valley Barbera.
The earliest Blended Learning student-made wines are also available while supplies last. The first is a 2012 dry Riesling that received an “excellent” rating from Great Northwest Wine, an online platform covering wine reviews and news. The second wine in the series is a red blend of Malbec, Cabernet Sauvignon, Merlot and Cabernet Franc.
In partnership with commercial vineyards and wineries, students are deeply involved, from monitoring grape ripening and harvesting, through crush, fermentation, barreling, and the final blend decision, to create these special edition wines.
Limited quantities: Get yours before they’re gone!
Blended Learning can be shipped to California, Oregon or Washington and purchased in the Tri-Cities area by contacting Debbie Schwenson at 509-372-7224 or firstname.lastname@example.org.
You can also purchase these student-made wines at the WSU Brelsford Visitor Center in Pullman; the WSU Connections stores in Spokane, Everett and Seattle; the Walter Clore Wine and Culinary Center in Prosser; and The Wine Alley in Renton.
All proceeds from Blended Learning wine sales directly benefit student learning and research projects in the WSU Viticulture and Enology Program.
– Erika Holmes
Tis the season: WSU donors enhance student learning
Albert Ravenholt Research & Teaching Vineyard expanded
Recent donations have allowed expansion of the Albert Ravenholt Research and Teaching Vineyard to two acres. Located on the Washington State University Tri-Cities campus, the vineyard complements the nearby WSU Wine Science Center, scheduled to open spring 2015.
Since 2007, undergraduate and graduate students have worked in the vineyard, conducting hands-on experiments and learning vineyard tasks. Students and instructors are fully responsible for tending the wine grape varieties grown there, which include Cabernet Sauvignon, Chardonnay, Gewürztraminer, Merlot, Riesling and Syrah.
“The Research and Teaching Vineyard aids my teaching by offering students outdoor, hands-on experience in a vineyard,” said Gretchen Graber, a graduate student who teaches undergraduate courses and also uses the vineyard for research.
WSU Extension staff will also hold educational seminars for wine industry members in the vineyard.
Members of the public and university staff gathered Dec. 4 to thank the vineyard advisory committee consisting of Roger Gamache, Jason Schlagel, Tom Waliser, and Derek Way, as well as local businesses that generously donated vineyard equipment and grapevines.
Donors include Cresline Plastic Pipe Co., Ewing Irrigation and Landscape Products, Fresno Valves & Castings, Gamache Vintners, Inland Desert Nursery, Jain Irrigation Systems, Linde Vineyard Supply, Nelson Irrigation, Quiedan Company, Rain Bird Corp., Sagemoor Vineyards, Waliser Winery & Vineyard, and Wilson Orchard and Vineyard Supply.
Riding and hauling in style
The Washington State University viticulture and enology program is grateful to be able to haul grapes, wine, and equipment with a Chevy Silverado 4×4 donated by Hall Chevrolet-Buick in Prosser.
The truck has a leased value of $6,000 per year.
Gov. Inslee reappoints Ted Baseler to WSU Board of Regents
Ted Baseler, Washington State University alumnus, CEO of Chateau Ste. Michelle Wine Estates, and a leader in the Washington wine industry for more than 25 years, has been reappointed to his second full term on the WSU Board of Regents. His reappointment runs through Sept. 30, 2020.
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