That permit was enough to scare most small timers off. Dad and a neighbor set up a still to ferment the sorgham they were using to feed cattle. According to them, the cattle did better on the fermented mash than the raw sorgham and they were going to get rich selling the ethanol to Texaco. In the end, it wasn't worth the effort, even when they burned it themselves in farm machinery. Texaco demanded a purity level that was pretty much out of reach for a small producer. The main problem was the water absorption level which was pretty much impossible in a humid climate.
Nothing was added to make it undrinkable (man, a cocktail with that stuff put Everclear to shame) and I don't recall seeing any particular security setup. Hell, one slug of that stuff and you lost all desire for a nip of anything for a while!