Wine tastings inevitably involve some form of grading or ranking the wines, since the objective of tastings is to determine which wine is best, second best, etc., at least among the tasters on that particular occasion. Much has been written about the care that has to be taken that judges are not influenced by extraneous and irrelevant factors and that they do not influence one another. Ultimately, of course, the views of the judges need to be congealed in a single ranking that expresses the “social preference” among the wines. And therein lies the rub: how to aggregate individual preferences into a social ranking.