The top of the line of Jim Beam's Small Batch Collection, Bookers is a 127.9 proof monster (at least my current bottle). Booker's is a small batch offering (a vatting of a relatively small number of casks), bottled at full cask strength which varies in proof and age from 121 to 127 proof (according to the web site, because the distiller chooses casks for each batch by flavor and the strength of each cask is unique) and from 6-8 years in the barrel (for the same reason). I guess my 127.9 proof example is "pushing the envelope" for Bookers. I'm not complaining. Alcohol is a flavor carrier and Bookers is a big flavor bomb.
The dark tea orange color speaks of a heavy char in the barrels and you can smell it. The toffee caramel aromas mix with the char to produce dark chocolate / cocoa notes. There's also vanilla and tobacco and leather in there. As Master Series reviewer Paul Pacult notes - there a "paraffin" note.
Take a sip and pure sweetness hits first. An intense sugar hit like maple syrup right on the tip of your tongue. The midpalate mammoth wallop of orange fruit (citrus / apricot), toffee, and caramel corn hit a nanosecond later followed by spirit heat, wood tannins, oiled leather and vanilla aromatics from oak. That paraffin note I own to Paul Pacult shows up here as well. The high proof makes itself known in the huge midpalate hit and in a big spicy burn which hangs on for minutes as this bourbon finishes long and simple with a wood smoke, sugar glow, sourmash twang, and burnt orange throat bitterness.
Wow! I'm after another sip right away, but at this high a proof I must take my time. The first big question is "can I use water"? You always can, but sometimes it robs a whiskey of its heart. The answer here is "yes you can". You can put quite a bit of water into Bookers and it still tastes clearly of Bookers (i.e. delicious). It loses some intensity (particularly the aroma and midpalate explosion) but might gain something in the fruit esters department. It certainly is easier to drink with some water.
Bookers is clearly the most powerful bourbon flavor experience I've had so far. The flavor profile is first rate too: distinctive, complex, and luscious. Excellent stuff!