I want to talk about two things I believe and why I believe them.
The first thing I believe is that there is, or rather was, a distinctive, one-of-a-kind whiskey known as Michter's Original Sour Mash Whiskey, that has a mash bill of 38 percent rye, 50 percent corn and 12 percent malt, as reported by Michael Jackson in his World Guide. I believe this whiskey was first made in 1951 and made periodically thereafter until 1989.
Assuming the mash bill above is correct, they deliberately wanted to make this not bourbon. Why? What follows is speculative, but I think it makes sense. Here is their thinking: Pennsylvania doesn't make bourbon, that's a Kentucky thing. Pennsylvania makes rye, but people don't like rye anymore. Let's make something that's closer to bourbon, so more people will like it, that's still close enough to straight rye to satisfy our traditional Pennsylvania consumers. Thus was Michter's Original Sour Mash Whiskey born. To further appeal to Pennsylvania heritage fans, they would bottle it in a crock rather than a bottle, and give it a Pennsylvania Dutch aura.
They may, too, have been looking at Jack Daniel's which managed to thrive without being either from Kentucky or being bourbon. Bourbon was "me too." Better to be distinctive.
The second thing I believe is that pot still distillation was something Forman and Beam always wanted to do but never did until the bicentennial distillery came along, and that wasn't a production system. It was a scale model.
I believe these two things because making a distinctive mash bill is fairly easy. A typical modern (i.e., post-1933) American whiskey plant can easily make different recipes. The term "continuous still" can be misleading. This may sound contradictory, but continuous still production is done in batches, just like pot still production.
Column stills are typically run for a week to ten days. During that period they truly run continuously, 24-hours-a-day. Remember that to run the stills you need a continuous supply of beer, which means you have fermenters going, cookers going, all in a choreographed ballet. The front end of the process is two to three days ahead of the back end of the process. After a run of 7 to 10 days, the pipeline is allowed to run dry, the still is shut down, allowed to cool down, and is cleaned out. Work never really stops, because while the still is being cleaned the next batch of mash is being cooked.
Between runs is when you change recipes. You can do many runs with the same recipe, or change the recipe with every run. It's not a big deal. A run can be no more than, say, ten days, but it can be of any length up to ten days, with the smallest run being probably the contents of one fermenter.
That is why contract distiller, as I believe the Schaefferstown distillery was, could be a reasonable business model. Michter's Original was, in effect, a periodic run, another contract. That's why, to John's point, it may have been made from time to time at distilleries other than Schaefferstown. For that matter, since for most of the brand's life there was no Michter's distillery, it was only made "at Michter's" before 1956 or after 1975, even if it was made at the Schaefferstown distillery.
I believe Forman had a pretty good run with Michter's, the brand. You can think of the brand and the distillery as two separate businesses. The distillery seems to have struggled more than the brand, though the brand too seems to have been dead by the end, though not for long. Nor did it stay dead for long, only about ten years.
Like I said, that's easy, making a proprietary recipe. Making it in an all pot still operation, that isn't easy. That's hard. As we know from Woodford Reserve, making American whiskey in a pot still requires a lot of adaptation. Pot stills didn't go out in the early 20th century, right before prohibition, they went out when column stills were intoduced in the middle of the 19th century. Everett Beam knew, I'm sure, as much as anyone, but no one in America had operated a production scale pot still operation for several generations.
Yet despite the fact that a true pot still distillery in the post-prohibition era would have been quite a novelty, there appears to be zero information about any details of this supposed pot still operation. What we have is a slogan, a name, and I believe that is all there ever was. I imagine a conversation like this:
Beam: It's just not practical today to make American Straight whiskey in pot stills.
Forman: But it would sure sound good, "Michter's Original Old-Fashioned Pot Still Whiskey."
Beam: Well, the doubler is technically a pot still.
Forman: Close enough! "Michter's Original Old-Fashioned Pot Still Whiskey" it is.
And thus was a legend born.