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g WINE g rAoKw i n g rape M ING either due to changes in the nature of the complexing molecules over extended time (a common event in red wines) or from precipitation of calcium tartrate. The various laboratory tests are empirically derived predictive indexes, and each has proponents who have used them for many years. Although from a theoretical standpoint all the tests have inconsistencies or application issues, they are in daily use in the wine industry. Many winemakers find reassurance over many years of using a specific test for what "expected" results should be and have derived experiential parameters for pass/fail levels for their chosen predictive index. Challenges occur when personnel, winemaking techniques and analytical parameters change. The recent introduction of colloidal additives and electrodialysis treatments have, in particular, demonstrated that an understanding of both cellar treatments and laboratory methods are required to appropriately apply these new technologies. PWV Bibliography Berg, H.W., and M. Akiyoshi. 1971 "The Utility of Potassium Bitartrate Concentration: Product Values in Wine Processing." Am. J. Enol. & Vitic. 22: 127 – 134. Boulton, R. 1983 "Technical Notes: The Conductivity Method for Evaluating the Potassium Bitartrate Stability of Wines – Part II" in Enology Briefs (G. Cooke, Ed.), Cooperative Extension, University of California. April/May. Boulton, R., et al. 1996 Principles and Practices of Winemaking. New York: Chapman and Hall. Dharmadhikari, M. Methods for Tartrate Stabilization of Wine. Iowa State University Midwest Grape and Wine Industry Institute Outreach and Extension. www.extension.iastate.edu/wine/methodstartrate-stabilization-wine. Guadalupe, Z. and B. Ayestaran. 2008 "Effect of Commercial Mannoprotein Addition on Polysaccharide, Polyphenolic, and Color Composition in Red Wines." J. Agric. Food Chem. 56: 9022 – 9029. Lubbers, S. et al. 1993 "Effect ColloideProtecteur D'Estraits de Parois de Levures sure la Stabilité Tartrique d'une Solution Hydro-Alcoolique Modèle." Journal International des Science de la Vigne et du Vin 27 (1): 13 – 22. Moutounet, M., D. Bouissou, and J.L Escudier. 2009 "Determining the Degree of Tartaric Instability (DTI) Principle and Applications." Presented at Technology Day of the Champagne Oenologist Union, Epernay, France, Oct. 15. Ribereau-Gayon, P., et al. 2000 Handbook of Enology, Vol 2: The Chemistry of Wine Stabilization and Treatments. New York: John Wiley and Sons. Zoeckelin, B. et al. 1995 Wine Analysis and Production. New York: Chapman and Hall. Zoecklein, B. 1998 "A Review of Potassium BiTartrate Stabilization of Wines" (Publication 463-013) www.apps.fst. vt.edu/extension/enology/downloads/ PotBitar.pdf. Patricia Howe has more than 30 years of winemaking production experience as winemaking technical director at Domaine Chandon, Mumm Napa and the late Allied Domecq/Beam Wine Estates. She has a BS in fermentation science and a MS in food science (sensory science emphasis), both from UC Davis, and also worked there as a teaching laboratory manager. Her past business experience includes being owner/ president of ASCENT Laboratories LLC, an applied sensory and analytical wine laboratory in Napa, Calif., and working at ETS Laboratories. She is currently the owner/ winemaker of Patricia Howe Wines, adjunct instructor for VESTA and review process manager for the American Vineyard Association and a lecturer in enology at the Cornell University Department of Food Science in Ithaca, N.Y. 2 BARREL STEAMING MACHINE AUTOMATED STEAMING! ! W NE 2 & 4 Barrel Washing • 2 & 4 Barrel Steaming Barrel Processing Lines • 1/2 Ton Bin Washing Systems 35 lb. Picking Lug Washers • Custom Cellar Equipment 1650 Almar Parkway, Santa Rosa, CA 95403 P. 707-573-3150 F. 707-573-3140 www.tombeard.com E. jmendoza@tombeard.com pr actica l win ery & vin eya rd APRIL 20 13 63