The size, number and position of the plates affect how complete a fractionating can be done with a given amount of mash or wash moving through the column. The larger and more sophisticated the column, the easier it will be to get a rectified product, i.e., a GNS of about 96% alcohol by volume. But the important thing to remember is a column still (any type) can be adjusted to produce a lower proof spirit. So the column stills in Kentucky either by design or the way they are operated, produce spirit at less than 160 proof (often much less) to be aged into bourbon. Therefore they are not that different from pot stills which produce alcohol at similar (final) tallies although in a different way and possibly requiring more distillations to do it. Some differences remain, e.g. live steam hits the mash in the column stills to do the separation and heat is applied to a pot to boil the contents, so the processes are not identical (apart that is from issues of throughput, energy efficiency and personnel requirements). It seems too at whatever proof the column delivers the resultant spirit it is "cleaner" than that issuing from a pot still. This may not be only a question of proof differences. I am sure, say, Craig and Parker Beam would know the answer to that one. Certainly one should not assume one still will necessarily make a better whiskey than the other. In considering the other day Woodford Reserve vs. Ancient Age Bonded, I felt the latter was better, for example. WR is only partly a pot still product and it has its particular profile and style. Possibly other pot still bourbons, if and when they emerge, will be sensational in taste and a clear advance on anything the Bluegrass columns have produced to date, but I doubt that will happen. More likely some pot still bourbon will be good, some very good (which WR generally is) and some great. That is true now of column still whiskey.

Gary