Every distillery has a tasting panel. Jack Daniel's probably has the biggest at something like 45 people, but the Master Distiller is typically the final decision-maker in that regard. In the case of the Van Winkle products, Julian would have the final say rather than Harlen. Supposedly, Elmer still has the final say on his namesake product. There may be some other exceptions, but it is Harlen for the most part.