By Chris Gerling
Hot water is used to clean and sanitize oak barrels, and Jackson Family Wines — the leading producer of Chardonnay sold by the glass in the United States — requires a lot of it. Their flagship Kendall-Jackson brand uses approximately 60,000 barrels to support demand. Former Cornell student Torey Arvik (Ph.D. '03) has validated a water recycling process for use in washing barrels that has the potential to cut their on-site water use in half, lower energy costs, and reduce total wastewater production.
Arvik, a microbiologist who worked on molecular testing of Brettanomyces at Cornell, developed wine testing methods at ETS laboratories in St. Helena, California before joining Jackson Family Wines as director of technical services in 2007.
In a winery, barrel sanitation is a process that requires large quantities of water and energy. Washing barrels with hot water under high pressure is an effective hygiene method, but its water and energy use detract from the sustainability of winery operations and generate millions of gallons of wastewater.
In a traditional barrel cleaning system, water is first heated to 180 °F for high-pressure washing of barrels, and then the hot water and residue are treated as wastewater. The new system aims to capture both the water and the residual heat for re-use through a "catch and clean" principle. The water used for washing one barrel is collected, filtered and reused. For the next barrel, the recycled water only needs to be heated 20-50 degrees instead of the usual 120 degree input. The sturdy unit is designed to run for years, thus earning the name Kantharos, after the bottomless wine container of the Greek god Dionysus.
"Kantharos is one vision for sustainability in the wine industry," says Arvik. "Our goals are to be able to reuse water as many times as possible and potentially remove the need for large wastewater treatment ponds."
The primary challenge is to ensure the recycled water is not a source of contamination of barrels. That is not a problem for the Kantharos system. Its harmonically vibrating stacks of conventional media membranes filter out microbes and individual molecules down to 150 molecular weight. According to tests performed on the recycled water, it's still clean and usable after nine continuous uses — nine trips through nine barrels.
Currently the facility is planning to reuse water five to six times during a standard work day, Arvik reports. And to test the limits of the system, Arvik and the Kantharos team challenged a lab-scale version of the equipment with varying extremes of winery waste to locate the limit for failure. They used residues from tank bottoms, diatomaceous earth, clay fining agents, and even pond water. The unit not only continued to run undeterred, it also returned water that exceeded the most stringent drinking water quality standards, plus a concentrated waste product that can be used for alternative energy.
While the price tag — close to $1 million — may be prohibitive for a smaller winery, the water and energy savings could be significant for large wineries, and leave more water in aquifers.
"A traditional pond can cost half as much to put in as this novel system. Replacing a pond can cost even more. If we can implement it at our largest facility with 70,000 barrels, we will reduce on-site water use by at least 40% and save thousands of dollars on fuel expenditures each year," estimates Arvik. "This would also keep tons of CO2 out of the atmosphere, since we would not need as much energy to move and heat water."
With wineries looking to reduce their carbon footprint, improving barrel and tank washing methods is a key process to target because it affects water use, energy consumption and wastewater generation.
Chris Gerling is an extension enology associate with the Department of Food Science at the New York State Agricultural Experiment Station.