Black hole (beverage)

From Memory Alpha, the free Star Trek reference

A black hole is a somewhat repulsive Ferengi drink that Jadzia Dax enjoyed having for breakfast. Dax was introduced to the black hole by a bartender she has known for 100 years. (DS9: "The Circle", "Playing God")

When Rom became a technician on Deep Space 9 in 2372, he told Quark that he had wiped his last table and mixed his last black hole. (DS9: "Bar Association")

The drink was ordered by another customer later that year. (DS9: "Hard Time")

Quark offered the exhausted Kira Nerys a frosty Bajoran ale or a black hole in 2373, but eventually brought her warm Enyak's milk to help get her sleep. (DS9: "Ties of Blood and Water")