High Brix Grapes and High Alcohol Wine
Evidence is emerging of a substantial increase in the sugar content of wine grapes at harvest. This increase may be a consequence of changes in weather patterns, or changes in cultural practices by growers, or both. One possibility is that it reflects a response to the market. Delaying the harvest and other cultural practices can result in riper fruit with more concentrated flavors (which may contribute in an intended fashion to desired quality attributes of the wine), but also a higher sugar concentration (which may be an undesired side-effect, because it results in higher alcohol content of the wine, and makes wine making more difficult). Wineries are developing and applying practices to deal with excess alcohol without compromising the quality of the wine.
The objective of this project is to explore the causes and consequences of increases in sugar content of wine grapes, and the resulting economic implications for wine grape growers, wine makers, and wine consumers. It will entail an examination first of what has been happening to the sugar content of wine grapes, and in the alcohol content of wine, primarily in California but also around the world. By exploring differences in the extent of the phenomenon and its timing according to variety and location of production (which is a proxy for market segment) of grapes, we hope to establish some indication of the extent to which increases in sugar content of grapes and alcohol content of wine are likely to have been driven by choices by growers and winemakers (in a response to perceived market demand) relative to exogenous effects of changes in weather patterns or climate. Further elements of the work will explore more directly the derived demand for higher brix wine grapes and the costs to wine grape growers of supplying them, including increased risk. This project will have some intersection with other Center projects including work by Sumner and Lee (on pricing of wine grapes) and Bar-Am and others (on economic effects of climate change).