We propose a structural empirical approach a la Levinsohn and Petrin (2003) to disentangle the effect of experts' grades from the effect of unobserved quality on the pricing of experience goods. Using a panel data set of 108 châteaux selling wine on the Bordeaux "en primeur" market, we provide some empirical validation for the theoretical result that the price set by wine producers is used as a signal for wine quality. We confirm that experts' grades affect producers' choice of "en primeur" price above the effect of unobserved wine quality. Our empirical results also show that failing to control for endogeneity caused by the omission of unobserved quality leads to over-estimate the influence of experts' grades on the "primeur" price.