What's the rationale behind diluting the bitters down to 90 proof? Why not leave it at, say, 150 proof?
At 120 proof the heat overpowered the nuance...they were not a constructive addition to cocktails the 2-3 times I tried them in tests along the way. The water from the cooking process added another dimension and helped round out the flavors. It also had a different character and "shape" if you will than the spirits infused with the exact same material. Adding the water helped smooth out the flavors in an immidiate and extreme way. The burnt sugars added to the bitters also helped make those flavors "pop" more without adding any perceptable sweetness to the bitters themselves. And all this verbage boils down to the same thing that Toby said...so yeah.
Those are the actual effects dilution had, but as far as my rationale behind it...for one I've never seen a bitters recipe that did not call for dilution (at least not one I can recall offhand). Also no commercial cocktail bitters of which I am aware clocked in any higher than 100 proof. When the hobbyist or craft bartender makes his own bitters one can write off the dilution as an economic expedient, to stretch the return on investment by adding a free ingredient to an expensive one. When a commercial operation who is buying untaxed industrial alcohol by the tank car full is shipping out their bitters, which are legally a food additive (no tax), with a proof that moderate I figure their must be a reason. If higher proof in cocktail bitters (or baking extracts, etc) yielded a superior result one would think that someone out there would be doing it. Not a foolproof reasoning but it was good enough for me, which the aforementioned results confirmed as a sound decision. The fact that the amounts worked out so perfectly was a nice bonus as well.
I refrained from any further test runs today but tomorrow some sort of Martinez or Manhattan type thing is in order. Stay tuned. As a comparison I'll probably try out another Old Fashioned identical to the one I made this afternoon as well.
Edited by thirtyoneknots, 31 May 2009 - 10:26 PM.