The Hilgard Project and the Future
The Hilgard Project:
Web-based, Automated Wine Fermentations at UC Davis Winery.
Scott Professor of Enology
And Chemical Engineering
The University of California is in the design and construction phases of a building complex that will be known as the Robert Mondavi Institute for Wine and Food (RMI). The generous gift of $20M by Robert and Margrit Mondavi and the matching funds from the State of California, will establish a unique centre that is home to the Departments of Viticulture and Enology and of Food Science (see: http://robertmondaviinstitute.ucdavis.edu/).
Some of the greatest limitations to small-scale research winemaking are irreproducible mixing and poor temperature control that generally occurs in small-lot wine fermentors. In order to overcome these difficulties, we have moved towards an automated pumpover and cap-management system for red wines and a similar mixing procedure for white wines in our 2000L fermentors.
Each fermentor has a dedicated centrifugal pump, mounted vertically and connected to a fixed vertical stainless steel pump-over line. These line have been modified to permit up to four in-line probes to be introduced. The wine is dispersed evenly over the skin cap using a spinning irrigator. Skins and seeds are excluded from this stream by removable screens within each fermentor. The fermentors have also been modified to create middle and wall probe locations in the roof, four in the manhole skirt and 8 more around the base.
The on/off operation and the pump speed can be set and observed from a laptop or classroom computer.
The progress of all fermentations can be measured automatically by following the decrease in static pressure as the fermentation progresses. Our data can also be observed via the worldwide web, from anywhere on the earth. Previously developed models of fermentation can be used to compare the observed traces with that expected for ideal condition, and when needed calculated properties can be estimated in real time.
A color and phenolic measurement system is to be tested during the 2005 harvest. This will permit the first direct measurements of these attributes to be followed in real time.
For white wines, the mixing system enables measurements to include yeast cell mass to be made as well as fermentation progress. It also minimizes the sedimentation and stratification that often plagues white wines at various times during the fermentation
The automated pump-over system removes the need for students to return to the winery each night for the pump-over operation. The safety and supervision issues are eliminated and more attention can be given to detecting fermentation problems early. The closed system for pumping over and mixing tanks reduces the risk of contamination of fermentations due to the use of common hoses fittings and pumps. It also removes the need for the man-hole to be opened and the possibility of collection and handling of fermentation gases.
The software already installed provides advance control and database capabilities. (http://wineserver.ucdavis.edu/content.php?category=The%20Hilgard%20Project). This web-based measurement and control system is perhaps the most advanced systems to be used in the wine industry, worldwide.
These improvements have been made possible by many people in several companies. This includes, the Paul Mueller Company, OSI Software, Rosemount-Emerson, J Lohr Winery. Custom Stainless, Jordan Winery, Far Niente (Dolce), Lallemand, Vinquiry, Stavin Corp. and other individual donors. The guidance and assistance of Andrew Wilson and Owen Le Gare have made these accomplishments possible.
The Automated Wine Fermentation System of the Hilgard Project at the University of California, Davis