California Grape Sugar Increase

Too Much of a Good Thing? Causes and Consequences of Increases in Sugar Content of California Wine Grapes

Julian M. Alston, Kate B. Fuller, James T. Lapsley, and George Soleas*

ABSTRACT. The sugar content of California wine grapes has increased significantly over the past 10-20 years, and this implies a corresponding increase in the alcohol content of wine made with those grapes. In this paper we develop a simple model of winegrape production and quality, including sugar content and other characteristics as choice variables along with yield. Using this model we derive hypotheses about alternative theoretical explanations for the phenomenon of rising sugar content of grapes, including effects of changes in climate and producer responses to changes in consumer demand. We analyze detailed data on changes in sugar content of California wine grapes at crush to obtain insight into the relative importance of the different influences. We buttress this analysis of sugar content of wine grapes with data on the alcohol content of wine.

* Julian Alston is a professor in the Department of Agricultural and Resource Economics and Director of the Robert Mondavi Institute Center for Wine Economics at the University of California, Davis, and a member of the Giannini Foundation of Agricultural Economics. Kate Fuller is a PhD candidate in the Department of Agricultural and Resource Economics at the University of California, Davis. Jim Lapsley is Adjunct Associate Professor in the Department of Viticulture & Enology at the University of California, Davis and Academic Researcher at the UC Agricultural Issues Center. George Soleas is Vice President, Quality Assurance and Specialty Services, Quality Assurance, Liquor Control Board of Ontario. We are grateful for data provided by the Liquor Control Board of Ontario and Calanit Bar-Am. The work for this project was partly supported by the University of California Agricultural Issues Center. Authorship is alphabetical. 

Copyright 2010 by Julian M. Alston, Kate B. Fuller, James T. Lapsley, and George Soleas

http://vinecon.ucdavis.edu/spaw2/uploads/files/cwe1001.pdf