The aperol sour is a perfect little gem with everything we could want in a cocktail: its sweet, tart, a little bit bitter, jaw-droppingly pretty, and easy to make. Despite the name, its a great showcase for any bitter citrus apritif you like, although almost all other brands are more bitter and less sweet than aperol. An email request from a user (yes, we read them) set us off on a quixotic journey to find the best possible incarnation of this recipe. We employed our usual scientific technique: making every recipe we found in the first five pages of a google search, downing the results, and taking copious notes. In the end, the winner ended up being the recipe that the user herself sent along with the request, which she first discovered from a bartender at king tai in brooklyn. Thanks, nc