WSU opens research winery in Prosser

PROSSER – WSU now features the largest experimental, noncommercial winemaking facility in the Pacific Northwest.

The research winery, which is located at the WSU Irrigated Agriculture Research and Extension Center in Prosser, has a production capacity of about 5,000 gallons. The new facility was designed by enologists James Harbertson and Kerry Ringer, scientists in the WSU Department of Food Science. The facility will be used to conduct research in support of the region’s rapidly growing wine industry.

“We designed the winery for small-lot, research-scale production,” said Harbertson. The winery will produce multiple small lots of wines under controlled and reproducible conditions, said Harbertson and Ringer.

“We spent about six months designing the facility,” said Ringer. “We wanted to make sure that we had the capability to conduct the research the industry needs, so that meant ordering a lot of custom-made equipment.”

The experimental winery includes 73 stainless steel fermentation tanks that are temperature controllable. The tanks range from 26 to 260 gallon capacity. Temperature in the tanks is monitored and controlled by a Web-based system called TankNET.

With the new winemaking facility, Harbertson said, “there are lots of questions we can now address. But our main issues are pretty much all practical. How does one piece of equipment affect the winemaking process compared with another? And how do viticulture practices affect grape quality and, in turn, wine quality?”

“The winemaking facility represents another leap forward for viticulture and enology research at WSU,” said Dan Bernardo, dean of the College of Agricultural, Human, and Natural Resource Sciences. “By conducting winemaking research at this level of detail, we’re going to be able to support the state’s premium wine industry in new and exciting ways.”

Currently, Harbertson is collaborating with WSU viticulturist Markus Keller to compare wines made from own-rooted versus grafted vines. Currently, the majority of Washington grape vines are own-rooted. California and other wine industries typically use disease-resistant rootstock to which varietals are grafted. Washington producers have not needed to graft vines as root diseases are so far not a problem in the state.

“We want to be prepared if there is an invasion,” said Harbertson. The researchers plan to make wine from grapes from both own-rooted and grafted vines that are grown in the same vineyard. Chemical analysis and sensory evaluation methodologies will be used to compare the wines. Currently, the team is working with Merlot, Chardonnay and Syrah varietals.

In the near future, Harbertson and Ringer plan to conduct filtration experiments in order to address industry concerns about filtration removing flavor. They’ve prepared by obtaining pad, cross-flow and sterile filtration systems.

“The perception among winemakers is that filtration removes the volatile compounds that give wine its flavor and nose,” said Harbertson. “We want to find out if that’s true or not.”

Sterile filtration, which Harbertson described as the “gold standard” in filtration systems, removes microorganisms.

“Not filtering wine risks Brettanomyces outbreaks,” Ringer pointed out. Brettanomyces is a type of yeast that can cause off-odors and flavors.

The enology team plans to begin crush in mid-October. “Unless, of course, there’s a cold snap and we have to bring the grapes in early,” said Harbertson.

“Then it’s all hands on deck,” added Ringer.

WSU’s viticulture and enology faculty is made up of 23 professors, scientists and Extension educators located at facilities across the state.