Things that make you go, "Hmmmmmm..."
What do you suppose is the reason for the bourbon industry's fascination with 107 proof? I was writing another message here, which concerned two 107-proof brands, and stopped for a minute to think of how many there are. I counted eight in my own collection alone...
Ancient Age Barrel 107
Elmer T. Lee 107 Proof
Old Weller Antique 107 Brand
Heaven Hill Old Barrel Brand
Old Rip Van Winkle 10-Year-Old
Pure Kentucky XO
Wild Turkey Rare Breed (okay, it's about 108, but their version of "hunnert-proof" is 101)
I'm sure there are others. Now, I know that 100-proof (50% alcohol) had long been considered the "honest" strength of whiskey. In fact (I think I learned this from Chuck) the term "proof" derives from the the gunpowder/whiskey flash test, a way of "proving" that the liquor contains the desired fifty percent alcohol. 100-Proof is the standard for Bottled-In-Bond status. Many whiskey drinkers think of less-than-100-proof whiskey as somewhat substandard, although they may not mind adding some water or drinking their bourbon over ice. In fact, many good bourbons taste even better that way.
But mostly, there isn't a great deal of "more is better", at least not with bourbon. For one thing, bourbon is intentionally distilled at lower-than-possible proof. Alcohol can be distilled at up to 200 proof in a laboratory and is routinely distilled out at 190-195 proof in the same kind of stills that bourbon is made in. But distilling at that purity removes all the flavor. By law bourbon cannot be distilled at any higher than 160 proof, and in practice its usually much lower than that. In fact, there is a point of pride among distillers as to how low they take their "high wine" out at, with several claiming bragging rights (but not revealing hard figures, of course).
Similarly, the proof of the whiskey as it goes into the barrel is often much lower than it is allowed to be by law. Or by the accounting department for that matter. Because barrels are costly, and so is storage space and the labor costs of rotating them around the warehouse, there is an incentive to barrel the whiskey at a high proof (thus taking up as few barrels as possible) and then reducing with water just before bottling. And that is what is usually done. But again, the bragging rights go to the distiller who barrels at the lower proof. There really is a difference in flavor between bourbon which contains a larger percentage of water that has also aged for years in an oak barrel and bourbon that contains more "raw" water.
There is also the phenomenon of the increasing alcohol content. For reasons that are quite unclear to anyone, including the distillers themselves, while the total contents of a barrel of whiskey diminishes over the years (as much as 30%), the alcohol content increases slightly (room here for another discussion topic?). So my own personal guess is that 107 proof is about what would be expected to come out of a barrel of bourbon that had been 100-proof when the bung was first hammered down. Of course there are exceptions (Booker immediately comes to mind, and Old Grand Dad 114), but they're singular cases. The fact that 107 is seen so commonly make me think that it may be because 100 is the standard. On the other hand, as evidence that this might not be quite right, Baker (107), diluted to 90 proof with water doesn't taste the same as 90 proof Jim Beam Black Label.
So, whattya think?