Wikipedia
Booker's bourbon is one of the small batch bourbons produced by the Jim Beam distillery, which is owned by Beam Suntory (a subsidiary of Suntory Holdings of Osaka, Japan). Having the highest alcohol content of the brands in the Jim Beam " Small Batch Bourbon Collection", it is a cask strength bourbon. Booker's bourbon is aged between six and eight years and is bottled un-cut and without chill filtering at its natural proof between 121 and 130.6.
The brand began as bottlings of bourbon personally selected from barrels by Jim Beam's grandson, the late distiller emeritus Booker Noe. Noe originally bottled his straight-from-the-barrel bourbon as gifts to close friends and family, and launched his selections as a brand available to the general public in 1992. Each barrel of Booker's bourbon was hand-selected by Noe and was aged at the center of the rackhouse, where the company says that the temperature and humidity are the most favorable for fine bourbons.
While it is not necessary to cut the bourbon with water, a splash or two of distilled water is recommended (by Booker Noe) to unlock some of the flavor.