by cowdery » Wed Feb 02, 2005 8:40 pm
BIB doesn't require filtration.
There are doubtless lots of bourbons that could call themselves BIB. Mostly they don't because they don't think it means anything to the consumer.
Char level is a function of time. The gas jets flame on for X seconds for a #1 and Y seconds for a #2, so you get a 1/2 by splitting the difference. If you wanted to get silly about it, you could do a #2 5/16 if you wanted to.
Traditionally, #4 was the highest, the "alligator" char. This was somewhat arbitrary, but the cooperages said that if you burned the barrels more (i.e., longer) than that they would lose physical integrity. Then Buffalo Trace (naturally) started messing around to see if they could go futher and, again based on the traditional timing scale (I apologize, but I don't know the actual times, but it's something like 90 seconds for a #4), they pushed it up to a #7. Unfortunately, it didn't seem to really make the whiskey taste any different than a #4, so maybe the people who decided #4 was the limit knew what they were doing after all.