Prototype optical sorter, programmable fermentation tanks among innovations

Students at Walla Walla Community College are getting their hands on new technology that most professional winemakers only dream of using. Tim Donahue, director of winemaking at the college’s Center for Enology & Viticulture, revealed the results of two years of trials conducted by his students using VitiSort, a prototype optical sorter designed and built by Key Technology in Walla Walla, Wash.

He presented the information during a session covering new processing technology – which also included programmable fermentation tanks and self-cleaning tanks – held Feb. 10 at the annual Washington Association of Wine Grape Growers (WAWGG) conference in Kennewick, Wash.

“Optical sorting isn’t a whole lot different than hand sorting,” Donahue said. “But it saves some poor souls from the delirium of standing at a shaker table for hours on end.”

The key learning point for students, he said, is how optical sorting fundamentally changes how wine is made.

“It changes the way you react to wine, how long you do punchdowns, fermentation temperatures — basically all the parameters of winemaking,” he said. “It’s a really great tool to show that to students.”

What Donahue showed to the professionals at the WAWGG conference was startling. He and his students ran various trials with and without the optical sorter. Some of their initial findings included:

  • A 25% reduction in tannins using the sorter.
  • Lower alcohol in wines using the sorter, likely from the removal of dehydrated fruit.
  • Higher fermentation temperatures.
  • No significant changes to juice chemistry or microbiology.
  • Damaged fruit can be at least partially recovered using sorter.
  • Working on a much larger scale with new technology is Tim Jones, a winemaker at 14 Hands Winery in the Yakima Valley town of Prosser. 14 Hands is Washington’s second-largest winery and is owned by Ste. Michelle Wine Estates.

In March 2012, the Ste. Michelle team began working with Spokane Industries to design and build a self-emptying tank. Ten of the new tanks were delivered to 14 Hands in time for the 2013 harvest, and due to how well they work, more could be on the way, Jones told attendees.

Each tank has a 30,000-gallon capacity and can handle 100 tons of fruit at a time. In the past, the facility has been able to process about 9,000 tons of grapes per harvest. With the new tanks, it can now take on twice that with no significant overhead, no increase in labor costs and higher safety standards.

The new tanks use sweepers to remove pomace easily and safely. During his presentation, Jones showed videos of the tanks being self-cleaned in less than an hour.

The tanks also use three methods for doing pumpovers: rack and return, pumps and Pulsair. The 14 Hands crew focused primarily on the latter, which uses nitrogen bubbles to move the 30-ton caps. Winemakers at 14 Hands and Columbia Crest have long used Pulsair for mixing tanks, and they see this system as a great way to manage such large loads of fruit.

Tech at New Wine Science Center

Richard Larsen, research winemaker at Washington State University, will be using much smaller tanks at the new Wine Science Center when it opens this summer on the campus of WSU Tri-Cities in Richland.

The $23 million facility is through construction and now is being prepared for students and researchers to occupy it by the time classes begin in August. It was built by the city of Richland on land owned by the Port of Benton adjacent to the campus along the Columbia River. The land and building are being handed over to WSU, and the Wine Science Center will become part of the university’s viticulture and enology program.

During the technology session, Larsen took participants through a virtual tour of the facility, with a focus on the 192 new fermentation tanks. Each tank is 200 liters in size, and each workstation will have eight tanks, Larsen said. The tanks are being built by Spokane Industries and are being electro-polished, which will make cleaning easier.

Larsen explained how the Integrated Fermentation Control System (IFCS), built by Cypress Semiconductor, will work. Each tank will have an IFCS, which can track Brix every five minutes, giving winemakers a real-time view of the fermentation curve. It also constantly measures cap and must temperatures, and while it cannot do automatic punchdowns, it can do pumpovers. Winemakers can program them to occur as often as every 10 minutes. The tanks are heated and cooled by water rather than glycol, making them more environmentally friendly, Larsen explained.

He pointed out that the tanks are modeled after those the University of California-Davis installed in 2011, and the two universities will have opportunities to run virtual side-by-side experiments.

Andy Perdue is editor and publisher of Great Northwest Wine, a news and information company. He’s also the wine columnist for The Seattle Times.