Reid (CigarNV) and I have been talking lately about the effects of watering down the bourbon. We believe we see the dissolving of some of the tastes and enhancing (or uncovering) others.
It is known that the materials that are drawn out of the oak and into the juice are based on the proof of the whiskey, the time in the barrel and temperature (cycling as well as peak temps).
It is our belief that as you water down the bourbon from proof X to Proof Y the deeper vanillas and caramels break down first and the aldahydes and oaks break down last. This is even more evident with older (18 yr plus) bourbons.
Keeping the entry proof lower and allowing the bourbon to go into the bottle as close to the barrel proof as possible, you do not dissolve or dilute the rich flavors. If you have a higher entry proof, higher barrel proof and you reduce the proof into the bottle you dissolve more of the harsher flavors in the barrel and mask the better ones.
Anyhow, this is enough info to start a discussion thread