Wine grapes contribute significantly to the economy of California, with a gross production value of more than $2 billion in 2010. Studies on economic issues in the industry require measures of demand response to price, but despite the economic importance of this industry, estimates of elasticities of demand for wine grapes have not been published. We use a flexible form inverse demand system model to estimate elasticities of demand for wine grapes from three grape-growing regions in California, representing three different quality (price) categories. The resulting estimates of own-price elasticities are high, ranging from −2.6 for grapes in the low-price region to −9.5 for grapes in the high-price region. Such high elasticities are plausible given the role of international trade in wine, and they are consistent with synthetic estimates that we computed based on a combination of economic theory, data on market shares, estimates of some pertinent parameters in the literature, and informed guesstimates of values for other parameters.