Blue Stuff™ is an incredibly intoxicating liquid discovered many years ago in the Potemkin-B's Forward Lounge by Lieutenant Bjorn Vuelvas and Lieutenant Junior Grade Christiaan Back.
The myth is one of the most legendary aboard the Potemkin, and indeed in Starfleet as a whole. One night, after putting quite a dent in the ship's alcohol supply, the pair began searching the general stock for something different and unique.
Chris Back discovered a bottle of blue liquid that neither recognized. Its kick was unlike anything they had experienced before, and its taste was fantastic. After drinking the entire bottle, the two men were quite utterly incoherent.
Later, the two made a point to ask the bartender what the mysterious liquid was. He was unsure, and only knew that it had been in the stock since before he started bartending aboardship. To this day, the origin of Blue Stuff™ is unknown. It may be a cleaning solution or an alien liquor designed purely for intoxication. All that is known is that it appears in shipments from time to time and is extremely effective at killing brain cells.
Since its discovery, it has been given its legendary name, Blue Stuff™, and has been the highlight of parties where it has appeared ever since.