When Life Hands You Lemons…
When life hands you lemons of any sort, said WSU enologist Jim Harbertson in a recent talk to vineyard managers and winemakers, make lemonade. The metaphorical lemons being grapes from vines infected with grapevine leafroll virus — a serious problem that is best dealt with by ripping out infected plants and replacing them with plants that have been tested and certified as virus-free.
However, replanting is not always an option, Harbertson pointed out. “The grower may have contracts that need fulfilling or just a bottom-line economic situation that prevents immediate replanting,” he said. “Sometimes you just have to make the best of the situation,” or lemonade, as the case may be.
Harbertson is also quick to point out that leafroll virus is not a food-safety issue. “But working with fruit from infected vines does present winemakers with certain challenges.”
In his recent talk, Harbertson outlined the challenges and possible approaches vintners can use when making wine with grapes from infected vines. His observations and advice are based on a three-year series of experiments he performed in collaboration with WSU leafroll virus expert Naidu Rayapati. He explained that the most noticeable leafroll virus symptoms are reductions in grape color, Brix and yield. Berry color, for instance, is not as pronounced on infected plants in hot growing areas. Similarly, acids may be degraded because of warm weather.
Nevertheless, these are not insurmountable problems, according to Harbertson. For red wines, the simplest solution may be to seize control of time and temperature in the production facility. “More contact time usually equates to more extraction,” he said. That is, the longer the berries are in contact with the must, the more color is likely to be extracted. Likewise, color can be concentrated using saignée techniques, while tannins can be bolstered using pomace from a previous fermentation or by the addition of bagged tannins. “Please note that there is a legal limit to the addition of tannins,” he pointed out.
With white wines, the problems are generally not so severe, since loss of acidity and Brix may actually be desirable. The potential loss of ripening characteristics that give white wines their distinct aromas is likely to be a problem but Harbertson said that little or no research has been done in this area, and further study, especially on aroma compounds, is needed.
It is absolutely paramount to identify infected plants in the vineyard, Harbertson warned. “There are lots of infected vines in Washington and elsewhere. Variations in climate and variety can mask — or exaggerate — the symptoms. What is needed is a rigorous and ongoing commitment to data collection and storage – even if it’s just a notebook. Put a solid sampling routine in place and stick with it. If you suspect a disease problem, get [the vines] tested at a reliable laboratory.”
“And remember,” Harbertson concluded, “when life hands you lemons be sure to ask for the salt and a Corona, too.”
–Brian Clark
Learn more about grapevine leafroll virus, its management and its effects on winemaking by reading “The Mystery of the Fall Colors” in Voice of the Vine at http://bit.ly/leafroll.
Naidu Rayapati’s Extension publication “Grapevine Leafroll Disease” can be downloaded from http://bit.ly/cxBHUy.
Rayapati and undergraduate researchers conducted a survey of grapevine leafroll disease in a well-known Red Mountain vineyard; read “Iraq War Vet Comes Home to Wine Country” at http://bit.ly/cpuNdW.
In “The Virus Fighters,” Voice of the Vine visits Rayapati’s lab in Prosser, Wash., and learns about some new tools for diagnosing plant diseases: http://bit.ly/apzpxa.
Plant micronutrition deficiencies can also lead to color changes in grape leaves. For more on that, see “A Pinch of This, A Dash of That” at http://bit.ly/9qPPEV.
WSU Viticulture Prof’s Book Wins Major International Prize
It’s rare for a textbook to become a bestseller. It’s even more rare for that same book to be selected for a prestigious prize as well. But that is exactly the situation with “The Science of Grapevines: Anatomy and Physiology” by Markus Keller, the Washington State University Chateau Ste. Michelle Distinguished Professor of Viticulture. The popular book was pre-selling briskly on Amazon even before Elsevier’s Academic Press published it last year. And now it has won a Jury Award as best viticulture book of the year from the Organisation Internationale de la Vigne et du Vin (OIV; International Organization of Vine and Wine).
For over 80 years, the OIV has honored the year’s best books focused on viticulture, enology, wine and vine economics, wine and health, wine history, and wine in literature and art. Usually one, rarely two, but sometimes no award is given in each category. To be considered, a book must make a thorough and original scientific contribution that is of international relevance. Nominated books are assessed by a panel of specialists knowledgeable in the field, including university professors, journalists, scientists, and historians.
“I estimated annual sales [would] be maybe 500 copies,” Keller said, pointing out that the rapidly increasing popularity of wine is not necessarily tied to people’s interest in the science of wine grape production. “But ‘The Science of Grapevines’ sold over 1,300 hard copies, not counting e-books, in its first year, which is amazing to me.”
The perennially humble Keller may be amazed, but his colleagues are not. Stuart Weiss, a former Stanford University professor, and current chief scientist and founder of Viticision, a viticultural consulting group, said, “Markus did a fantastic job of collating and synthesizing the voluminous scientific literature on the grapevine, putting it in the broader context of plant physiology. It is an invaluable service to the viticulture community, the wine industry as a whole, and the broader scientific community. It is my ‘go to’ book for questions and answers.”
This isn’t the first time WSU viticulture and enology faculty have been honored with an OIV award. Charles Edwards, a WSU food scientist specializing in wine microbiology, was a co-recipient of a 2007 OIV award for “Wine Microbiology: Practical Applications and Procedures.”
Awards are given each year at a ceremony in December at OIV headquarters in Paris.
–Brian Clark
WSU Cougars Mediterranean Cruise
Join world-renowned WSU Viticulture and Enology Director Thomas Henick-Kling, CAHNRS Dean Daniel Bernardo ‘85, and other WSU and Cougar wine community leaders as they sail the Mediterranean on a private Cougar-chartered cruise, May 28 – June 2, 2012. Embark from Nice, France, and call at Calvi, Portofino, Livorno, Portoferraio and Rome.
Special pricing for the first 42 cabins start at $2,450 pp. Proceeds will benefit the WSU Viticulture and Enology program.
WSU Cougars Cruise pricing includes:
- All meals and snacks aboard ship
- Special gourmet wine tasting dinners prepared by our celebrity chef
- Featured wines served all day and evening throughout the cruise
- Special WSU Cougars wine tasting events
- Winemaker seminars
- Educational seminars on wine, food, and ports of call
- Special parties aboard ship
- Two special WSU cocktail parties with complimentary drinks and appetizers
- Live entertainment every night
- 24-hour room service
- Water sports at the Windsurf marina, including water skiing, sailing, and kayaking (weather permitting)
- Airport transfers in Nice and Rome
Learn more at http://bit.ly/cruisewine.