Growers and winemakers rarely consider what is involved in the practice of sensory evaluation, which is, after all, what every taster does when sampling wine.
Speakers at the Making Sense of Sensory Evaluation Symposium on the final day of the Eastern Section meeting of the American Society for Enology and Viticulture in Geneva, N.Y., addressed this topic in depth.
One speaker, Harry Lawless, from the Department of Food Science at Cornell University, defined sensory evaluation as “a scientific discipline used to evoke, measure, analyze and interpret those responses to products that are perceived by the senses of sight, smell, touch, taste and hearing.” It is used to reduce uncertainty and risks in making decisions and to ensure delivery of new products that will be accepted by consumers.
He reviewed three sensory evaluation tests:
• Discrimination tests that assess whether products are different and include triangle tests and duo-trio tests;
• Descriptive analysis, which is used for research projects and involves a trained panel and the use of intensity scales;
• Preference tests, in which consumers indicate their likes/dislikes for a product.
According to Lawless, sensory evaluation methods were developed by large food-processing companies with plenty of people and money to perform sensory testing. The wine business, especially in the East, doesn’t have the numbers or the financing for formal sensory evaluation. Small and medium-sized wineries don’t have enough people for conducting statistically valid studies, nor do they have enough wine for evaluation. In addition, their product -- the wine itself -- is always changing: in the glass, in the tank or barrel, and in the bottle.
Until the wine industry develops methods that address the problems of informal tasting and inadequate scoring systems, Lawless advised consumers: Let your own palate tell you if you like the wines.
Other speakers addressed a range of topics related to sensory evaluation. Terry Acree, a flavor chemist at the New York State Agricultural Experiment Station, Cornell University, discussed some of the chemicals identified in the past 40 years that contribute to making a varietal wine taste like a specific grape variety.
Zata Vickers, Department of Food Science and Nutrition, University of Minnesota, spoke about the biological/physiological and social/cultural aspects of how and when humans acquire a liking for wine. She also reported about testing done at the University of Minnesota on palate cleansers. Those in the wine industry will be interested to know that Vickers’ results show the best palate cleanser to use is water -- or nothing at all.
Anna Katharine Mansfield, Department of Food Science and Technology at NYSAES and organizer of the symposium, and Jordi Ballester, from the Department of Oenology, Institut Universitaire de la Vigne et du Vin, University of Burgundy, Dijon, France, addressed the topic of effective descriptive analysis. Ballester also looked at difference tests, how they vary and how they compare from a statistical analysis standpoint.