In this paper we provide a simple and transparent non parametric methodology to express the scores of each wine expert (15) on the same rating scale. We discuss the advantage of this methodology over a linear transformation. The non paramatric method ensures the comparability of scores among experts and allows for a relevant average calculation of available wine scores. This approach may be usefuel to wine professionals who seek to reduce uncertainties leading to improved market efficiency. Uniform scores for many Bordeaux en primeur wines can be freely accessed at globalwinescore.com.