The K-1 I buy at the bulk dealer pumps it out of 55 gal drums. In the summer I burn most of what he sells. In the winter, he sells a whole lot more to the space heater people. Never a problem.

Jet A has an oilier feel to it as it evaporates off your fingers than K-1, whatever that may mean. The additives are not that great of a percentage, however. I don't know of anybody who has seen a noticable difference if the fuel comes from a known good source.